April Meeting : “This Crowded Galaxy” · April Meeting : “This Crowded Galaxy” ... visit to...
-
Upload
duongxuyen -
Category
Documents
-
view
214 -
download
1
Transcript of April Meeting : “This Crowded Galaxy” · April Meeting : “This Crowded Galaxy” ... visit to...
April 2014
SOCIETY JOURNAL April Meeting : “This Crowded Galaxy” with Dr Nicholas Rattenbury Monday April 14th at 8:00pm
W e have known for the last 20 years that there are
other planets orbiting stars other than our own Sun. Alien worlds exist -- if not necessarily the aliens themselves.
The types of planets discovered to date show a wonderful
variety, from massive gas giant planets orbiting very close to
their host star, to cooler rocky planets. A recent discovery is of a population of free-floating "nomad'' planets, which roam
the Galaxy without a host star. How planets form -- and form
in such diversity -- is an open question. For an answer we will need a more thorough sampling of the planets in our Galaxy.
We have detected extra-solar planets by using radial velocity
measurements of stars, making transit observations,
gravitational microlensing and direct imaging. All these techniques are reaching maturity and are complementary in
their ability to detect planets of various type and which lie at
distances from close to our own Solar system all the way to
the centre of our Galaxy.
How we discover planets through gravitational microlensing is
in a state of transition. The field is moving away from the
original symbiosis of the survey and follow-up collaborations,
to using monolithic, high cadence, survey-only operations.
In this talk I will discuss the basics of detecting extra-solar
planets using microlensing, the present status of the field,
how the study will evolve and how my work will contribute.
I will also outline a proposal to construct a robotic research-
grade telescope in the Greater Auckland area, for research
and teaching.
SOCIETY JOURNAL, April 2014 2
Calendar of Events for 2014
April 2014 Programme
Fri 4 7:30pm Young astronomers with Margaret Arthur
Mon 7 7:00pm
8:00pm
Astrophotography Group with Keith Smith
Practical Astronomy With Bill Thomas
Mon 14 8:00pm Society Meeting TBA
Mon 21 8:00pm Film night with Gavin Logan. Earthquakes
Wed 23 7:30pm Council Meeting
Mon 28 8:00pm Society AGM
May 2014 Programme
Fri 2 7:30pm Young astronomers with Margaret Arthur
Mon 5 7:00pm
8:00pm
Astrophotography Group With Keith Smith Practical astronomy with Bill Thomas
Mon 12 8:00pm Society Meeting
TBA
Mon 19 8:00pm Introduction to Astronomy with Bernie Brenner and Peter Felhofer
Wed 21 7:30pm Council Meeting
Mon 26 8:00pm Film Night with Gavin Logan. The Seven ages of Starlight
Lunar Eclipse April 15. Starting at 6:00pm and lasting until 9:33pm.
See Alan Gilmore’s article on Page 16, paragraph 4
Seven Ages of Starlight A documentary showing how stars are created, age and eventually die. It covers the different types of stars and discusses what makes them different in terms of lifespan, chemical composition, size, density and luminance. Film is 1 hour and 28 minutes long and will be the only film shown on the night.
Craig McGee (ordinary) Richard Gardener (family) Gaz Eves (ordinary) Savita Vegil (ordinary) Louisa Welsh (ordinary) Riley Steyn (family)
New members Welcome
Member Notices
The library has copies of the journals from other societies and groups around the country and even Australia. You can borrow these by visiting the library or contacting the librarian, Tony Reynolds
Andrew has organised a group discount to members for the Australian Sky and Telescope. To take advantage of this offer and confirm the price, contact Andrew Buckingham on 473-5877 or by email at [email protected].
Film Night Monday April 21 at 8:00pm
Eartquakes.Their patterns of occurrence. The film looks at whether scientist will ever be able to predict them.
Film Night Monday May 26 at 8:00pm
SOCIETY JOURNAL, April 2014 4
Can we make it to Mars? By Gavin Logan
A large attendance at March’s film night watched a film which looked at the feasibility of a manned mission to the red planet.
Issues included how the astronauts would be fed on such a long trip, how they would be protected from small particles puncturing the spacecraft and how to design and manufacture light, less cumbersome and more flexible spacesuits.
The film looked at the potential to build a spacecraft with shielding material that can withstand being hit by small particles while travelling through space. The problems of weightlessness over the long period of time it would take to travel to Mars were also examined. The idea of having a revolving room that created the feeling of gravity on the spacecraft so astronauts did not suffer from excessive muscle and bone loss was also examined.
NASA's thermo stabilised foods were not only examined, but sampled by the film’s presenter. Many of these would last in satisfactory condition for two years, but after five years they were inedible. The idea of shrink wrap type spacesuits was canvassed and a test design of one was demonstrated.
The main film was followed by the February 2014 Sky at Night show which focused on Jupiter. Of interest to some society members was the part of this program which showed the important contribution amateur observations and photography
of Jupiter make towards our scientific knowledge of the planet.
Next month's film night with is on Monday April 21sth at Stardome and features a film entitled "12 things you didn't know about earthquakes". This is a documentary that covers the causes of earthquakes, their patterns of occurrence and
Cartoon of the Mars Rover racing a tortoise and snail to demonstrate how slow the Rovers move on Mars. Human explorers would need faster surface transport.
Society Dark Sky Group By Gavin Logan
A uckland Astronomical Society has formed a dark sky group for the purpose of educating members and the public
about the issues of light pollution and the loss of the dark sky. The first meeting of the group was very well attended with well over 20 people indicating that they wanted to become active members of this group. The group also intends to make submissions on all relevant local government and central government plans and papers about street and road lighting as well as lighting and buildings.
It will also assist in monitoring sky brightness (sky glow) and see if new lighting technology improves this when it is installed. Much discussion occurred about local issues of invasive street and building lighting being installed in areas where attendees of the meeting lived. It was decided that the group would actively pursue these, especially if they contravene the new guidelines that Auckland Council and Auckland transport have published. The proposed development controls and street lighting ordinances were discussed and the society will be making submissions on them.
It is hoped that if we can establish a good working group and that we can form a chapter of the International Dark Sky
Association. Anyone interested in joining this group please contact either Gavin Logan or Steve Hennerley. You do not have to be an astronomical Society member to belong to this group, but just have an interest in the subject.
Inaurural Group members: President Jim Dougherty, from left to right, Gavin Logan, Jim Dougherty, Lighting designer John McKensey and Society President Grant Christie.
5 WWW.ASTRONOMY.ORG.NZ
Celestial Navigation Expressions of Interest
Following my Introduction to Astronomy talk last Monday, there was some
interest in further Celestial Navigation sessions with the aim of using marine
sextants to determine position.
I am seeking expressions in interest from AAS members.
The program will take about 10 lessons of one hour duration on three
Mondays a month with perhaps a longer session on months with a fifth
Monday (June and September). Some prior knowledge of the Celestial Sphere
would be helpful although not essential. There is applied spherical
trigonometry however I have a range of Microsoft Excel templates which
crunches the calculations. I have access to a class set of six or seven
professional marine sextants.*
There will be some practical sessions at Long Bay beach during morning
twilight. It is important to be able to see the sea horizon and first magnitude
stars simultaneously. Evening sessions can take place at Muriwai gannet
platforms.
Morning twilight is easier as the location of stars can be seen before the sun rises while in the evening you are waiting for
the sky to dim enough before the stars to appear.
There are places for a minimum of ten participants while numbers would be limited to a maximum of 20. This topic is
something I teach four times a year. I have a range of resources to assist in this subject. So come and experience the time
honoured skill of being able to determine your location on earth using only a sextant and a chronometer.
Contact David Wardle directly by email at: [email protected]
David Wardle, Senior Lecturer, NZ Maritime School
Some pictures from the recent society visit to the New Zealand Maritime School Ship Simulator facility courtesy of Goran Ristic.
SOCIETY JOURNAL, April 2014 6
Did Alien Life Evolve Just After the Big Bang? From Science Daily
E arthlings may be extreme latecomers to a universe full of
life, with alien microbes possibly teeming on exoplanets beginning just 15 million years after the Big Bang, new research
suggests.
Traditionally, astrobiologists keen on solving the mystery of the
origin of life in The Universe look for planets in habitable zones around stars. Also known as Goldilocks zones, these regions are
considered to be just the right distance away from stars for
liquid water, a pre-requisite for life as we know it, to exist.
But even exoplanets that orbit far beyond the habitable zone
may have been able to support life in the distant past, warmed
by the relic radiation left over from the Big Bang that created
The Universe 13.8 billion years ago, says Harvard astrophysicist Abraham Loeb. [The Big Bang to Now in 10 Easy Steps]
For comparison, the earliest evidence of life on Earth dates from
3.8 billion years ago, about 700 million years after our planet formed.
Just after the Big Bang, the cosmos was a much hotter place. It
was filled with sizzling plasma, superheated gas, that gradually
cooled. The first light produced by this plasma is the cosmic microwave background radiation (CMB) that we observe today,
which dates from about 389,000 years after the Big Bang.
Now the CMB is freezing cold, around minus 454 degrees Fahrenheit (minus 270 degrees Celsius; 3 degrees Kelvin). It
cooled down gradually with the expansion of The Universe, and
at some point during the cooling process, for a brief period of
seven million years or so, the temperature was just right for life to form , between 31 and 211 degrees Fahrenheit (0 and 100
degrees Celsius; 273 and 373 degrees Kelvin).
It is the CMB's heat that would have allowed water to remain liquid on ancient exoplanets, Loeb said.
"When The Universe was 15 million years old, the cosmic
microwave background had a temperature of a warm summer
day on Earth," he said. "If rocky planets existed at that epoch, then the CMB could have kept their surface warm even if they
did not reside in the habitable zone around their parent
star." [Gallery: Planck Spacecraft Sees Big Bang Relics]
But the question is whether planets, especially rocky planets,
could already have formed at that early epoch.
According to the standard cosmological model, the very first stars started to form out of hydrogen and helium tens of
millions of years after the Big Bang. Heavy elements, which are
necessary for planet formation, were not around yet.
But Loeb says that rare "islands" packed with denser matter may have existed in the early universe, and massive, short-lived
stars could have formed in them earlier than expected.
Explosions of these stars could have seeded the cosmos with
heavy elements, and the very first rocky planets would have
been born.
These first planets would have been bathed in the warm CMB radiation, and thus, Loeb argues, it would have been possible
for them to have liquid water on their surface for several million
years.
Loeb says that one way to test his theory is by searching in our
Milky Way galaxy for planets around stars with almost no heavy
elements. Such stars would be the nearby analogues of the early
planets in the nascent universe.
The Cosmic Microwave Background (CMB) radiation tells us the
age and composition of The Universe and raises new questions
that must be answered.
Constant or not?
Based on his findings, Loeb also challenges the idea in cosmology known as the anthropic principle. This concept
attempts to explain the values of fundamental parameters by
arguing that humans could not have existed in a universe where these parameters were any different than they are.
So while there might be many regions in a bigger "multiverse"
where the values of these parameters vary, intelligent beings are
supposed to exist only in a universe like ours, where these values are exquisitely tuned for life.
For instance, Albert Einstein identified a fundamental parameter,
dubbed the cosmological constant, in his theory of gravity. This constant is now thought to account for the accelerating
expansion of The Universe.
Also known as dark energy, this constant can be interpreted as
the energy density of the vacuum, one of the fundamental parameters of our universe.
Anthropic reasoning suggests that there might be different
Artist's impression of Kepler-62f, a potential super-Earth in its star's habitable zone. Credit: NASA/Ames/JPL-Caltech
7 WWW.ASTRONOMY.ORG.NZ
values for this parameter in different regions of the multiverse,
but our universe has been set up with just the right cosmological constant to allow our existence and to enable us
to observe the cosmos around us.
Loeb disagrees. He says that life could have emerged in the early
universe even if the cosmological constant was a million times bigger than observed, adding that "the anthropic argument has
a problem in explaining the observed value of the cosmological
constant."
An artist's representation of the 'habitable zone,' the range of
orbits around a star where liquid water may exist on the surface
of a planet. A new study unveiled Nov. 4, 2013 suggests one in
five Sun like stars seen by NASA's Kepler spacecraft has potentially habitable Earth-size planets.
Edwin Turner, a professor of astrophysical sciences at Princeton
University, who was not involved in the new study, called the
research "very original, stimulating and thought-provoking."
Astrophysicist Joshua Winn of the Massachusetts Institute of
Technology, who did not take part in the study either, agrees.
"In our field, it has become traditional to adopt a definition of a
'potentially habitable' planet as one that has a solid surface and a surface temperature conducive to liquid water,” he said.
"Many, many papers have been written about the exact
conditions under which we might find such planets, what type of interior composition, atmosphere, and stellar radiation field.
Avi has taken this point to a logical extreme, by pointing out
that if those two conditions are really the only important
conditions, then there is another way to achieve them, which is to make use of the cosmic microwave background."
Closest, brightest supernova in decades is also a little weird
From Science Daily
T he closest and brightest supernova in decades, SN 2014J,
brightens faster than expected for Type Ia supernovae, the exploding stars used to measure cosmic distances, according to
astronomers. Another recent supernova also brightened faster
than expected, suggesting that there is unsuspected new
physics going on inside these exploding stars. The finding may also help physicists improve their use of these supernovae to
measure cosmic distance.
provoking new questions about the exploding stars that scientists use as their main yardstick for measuring The Universe.
Called SN 2014J, the glowing supernova was discovered by a
professor and his students in the United Kingdom on Jan. 21,
about a week after the stellar explosion first became visible as a pinprick of light in its galaxy, M82, 11.4 million light years away
in the Big Dipper. Still visible today through small telescopes, it is
the brightest supernova seen from Earth since SN1987A, 27 years ago, and may be the closest Type Ia supernova -- the kind
used to measure cosmic distances -- in more than 77 years.
When University of California, Berkeley, astronomer Alex
Filippenko's research team looked for the supernova in data collected by the Katzman Automatic Imaging Telescope (KAIT)
at Lick Observatory near San Jose, Calif., they discovered that
the robotic telescope had actually taken a photo of it 37 hours after it appeared, unnoticed, on Jan. 14.
Combining this observation with another chance observation by
a Japanese amateur astronomer, Filippenko's team was able to
calculate that SN 2014J had unusual characteristics -- it brightened faster than expected for a Type Ia supernova and,
even more intriguing, it exhibited the same unexpected, rapid
brightening as another supernova that KAIT discovered and imaged last year -- SN 2013dy.
"Now, two of the three most recent and best-observed Type Ia
supernovae are weird, giving us new clues to how stars
explode," said Filippenko, referring to a third, though
apparently 'normal,' Type Ia supernova, SN 2011fe, discovered
three years ago. "This may be teaching us something general
about Type Ia supernovae that theorists need to understand. Maybe what we think of as 'normal' behavior for these
supernovae is actually unusual, and this weird behavior is the
new normal."
A paper describing the SN 2014J observations -- the first
published on this newly discovered supernova -- was posted
online by The Astrophysical Journal Letters and appeared in the
March 1 print issue.
A colour composite of SN 2014J, located in the "cigar galaxy" M82, 11.4 million light years away, made from KAIT images obtained through several different filters. The supernova is marked with an arrow. Other round objects are relatively nearby stars in our own Milky Way Galaxy. Image by W. Zheng and A. Filippenko, UC Berkeley.
SOCIETY JOURNAL, April 2014 8
Type Ia supernovae as standard candles
Astronomers noticed decades ago that Type Ia supernovae
explode with about the same brightness, no matter where they
are in The Universe. This makes them good "standard candles" with which to judge distance. In the 1990s, two teams (both of
them included Filippenko) used Type Ia supernovae to determine
the distances to galaxies, compared distance with velocity and discovered that The Universe is expanding faster and faster,
rather than slowing down as expected. The teams' leaders,
including UC Berkeley astrophysicist Saul Perlmutter, shared the
2011 Nobel Prize in Physics for this discovery.
While the latest discoveries do not contradict these results,
refinements in understanding Type Ia explosions could help
improve distance measurements and lead to more precise calculations of the expansion rate of The Universe, thereby
setting constraints on the nature of "Dark Energy," a still
mysterious energy comprising 70 percent of The Universe and
thought to be responsible for its acceleration.
The new data also provide information about the physics
occurring in the core of the explosion.
A Type Ia supernova is thought to be the explosion of a white dwarf -- an old and very dense star that has shrunk from the
size of the Sun to the size of Earth. When a white dwarf has a
stellar companion, it can sometimes gain matter from it until the
white dwarf becomes unstable, completely obliterating itself through a gigantic nuclear explosion.
New telescopes to catch more supernovae
Because of the importance of supernovae in measuring The
Universe, many new telescopes, such as the Palomar Transient
Factor in San Diego County and the Pan-STARRS in Hawaii,
continually rescan the sky to discover more of them. The KAIT
telescope has a smaller field of view than newer ones do, so Filippenko's team has switched its focus to discovering
supernovae earlier: it scans the same patches of sky every night
or every other night. The sooner a new explosion is discovered,
the sooner astronomers can capture information, such as spectra showing how the supernova brightens in different
colours or wavelengths.
Last year, for example, KAIT and Filippenko's Lick Observatory Supernova Search (LOSS) team discovered and photographed SN
2013dy within two and a half hours of its appearance, earlier
than for any other Type Ia. KAIT, which is operated by
postdoctoral scholar WeiKang Zheng, is programmed to automatically take images of likely supernovae in five different
wavelength bands, and in 2012 captured one supernova, SN
2012cg, three minutes after its discovery.
"Very, very early observations give us the most stringent
constraints on what the star's behavior really is in the first stages
of the explosion, rather than just relying on theoretical
speculation or extrapolating back from observations at later times, which is like observing adolescents to understand early
childhood," Filippenko said.
Filippenko's colleagues include Zheng; UC Berkeley graduate student Isaac Shivvers; assistant specialist Kelsey I. Clubb;
postdoctoral scholars Ori D. Fox, Melissa L. Graham, Patrick L.
Kelly and Jon C. Mauerhan; and amateur astronomer Koichi
Itagaki of the Itagaki Astronomical Observatory in Yamagata, Japan, who captured an image of SN 2014J just 20 hours after it
exploded.
Possible evidence for dark matter particle presented at UCLA physics symposium From Science Daily
D ark matter, the mysterious substance estimated to make
up approximately more than one-quarter of the mass of The Universe, is crucial to the formation of galaxies, stars and
even life but has so far eluded direct observation. At a recent
UCLA symposium attended by 190 scientists from around the
world, physicists presented several analyses that participants interpreted to imply the existence of a dark matter particle. The
likely mass would be approximately 30 billion electron-volts, said
the symposium's organizer.
Dark matter, the mysterious substance estimated to make up
approximately more than one-quarter of the mass of The
Universe, is crucial to the formation of galaxies, stars and even
life but has so far eluded direct observation.
At a recent UCLA symposium attended by 190 scientists from
around the world, physicists presented several analyses that
participants interpreted to imply the existence of a dark matter particle.
The likely mass would be approximately 30 billion electron-volts,
said the symposium's organizer, David Cline, a professor of physics in the UCLA College of Letters and Science and one of
the world's experts on dark matter.
The physicists at the Feb. 26-28 event were in agreement that
"there seems to be an excess in the available data that could be due to dark matter," Cline said.
"At this symposium, it was obvious that excitement is building
in the fields of dark matter theory and, especially, detection," said Cline, who noted that there are several ways dark matter
can be observed and that all were discussed at the UCLA
meeting.
"Because dark matter makes up the bulk of the mass of galaxies and is fundamental in the formation of galaxies and stars, it is
essential to the origin of life in The Universe and on Earth,"
Cline said.
9 WWW.ASTRONOMY.ORG.NZ
The first evidence for dark matter was discovered in 1933 using
the Mt. Wilson telescope outside of Los Angeles. More recently, various theoretical models and detector improvements have
made it possible to search for dark matter particles at extremely
sensitive levels -- some of the most sensitive measurements
made by any scientists in the world.
One search technique involves using the vast amount of dark
matter in our galaxy. The NASA Fermi Satellite Telescope, an
international collaboration involving NASA, the Goddard Space Flight Center and the SLAC National Accelerator Laboratory,
searches for gamma rays -- very high-energy light particles --
from this dark matter.
There are models of dark matter that would allow a signal in the galactic dark matter consistent with the claims at the meeting
and provide a small interaction consistent with the "null results"
in the direct dark matter searches all over the world.
Much larger direct dark matter detectors are being planned in
the U.S., Italy, Canada and China (including Xenon 3 Ton, LUX-
ZEPLIN 7 Ton and DarkSide, which will weigh five tons). These
larger detectors potentially could see a dark matter signal in the next few years, Cline said.
Dark matter is widely thought to be a kind of massive
elementary particle that interacts weakly with ordinary matter. Physicists refer to these particles as WIMPS, for weakly
interacting massive particles, and think they originated from the
Big Bang. WIMPs are thought to be streaming constantly
through the solar system and Earth.
Another search method is to look for an interaction of a WIMP with xenon or argon nuclei and others (like germanium) in very
low-background laboratories deep underground in Italy, the
U.S., Canada, China and other countries. While these
experiments have seen no signal of a WIMP above 30 billion electron volts, "there is no incompatibility with the interesting
excess in the FERMI data," Cline said.
The discovery of the Higgs boson, which won the 2013 Nobel Prize in physics, plays a role in the search for dark matter, Cline
said, adding that this topic was discussed in detail at the
meeting. Dark matter, he said, could consist of axions, WIMPs or
sterile neutrinos, all of which were discussed at the symposium.
The UCLA dark matter symposium is convened every two years;
this was the 11th such meeting. Cline said he and his
colleagues hope to clarify the dark matter puzzle at the 2016 symposium.
It was at this same dark matter symposium in 1998 that two
groups of scientists reported that The Universe is accelerating, as
well as expanding, a finding Cline described as "one of the greatest discoveries in the history of science."
Tremors of the Big Bang: First direct evidence of cosmic inflation From Science Daily
A lmost 14 billion years ago, The Universe we inhabit burst
into existence in an extraordinary event that initiated the Big Bang. In the first fleeting fraction of a second, The Universe
expanded exponentially, stretching far beyond the view of our
best telescopes. All this, of course, was just theory. Researchers
now announce the first direct evidence for this cosmic inflation. Their data also represent the first images of gravitational waves,
or ripples in space-time. These waves have been described as
the "first tremors of the Big Bang." Finally, the data confirm a deep connection between quantum mechanics and general
relativity.
Researchers from the BICEP2 collaboration today announced the
first direct evidence for this cosmic inflation. Their data also represent the first images of gravitational waves, or ripples in
space-time. These waves have been described as the "first
tremors of the Big Bang." Finally, the data confirm a deep connection between quantum mechanics and general relativity.
"Detecting this signal is one of the most important goals in
cosmology today. A lot of work by a lot of people has led up to
this point," said John Kovac (Harvard-Smithsonian Center for
Astrophysics), leader of the BICEP2 collaboration.
These groundbreaking results came from observations by the BICEP2 telescope of the cosmic microwave background -- a faint
glow left over from the Big Bang. Tiny fluctuations in this
afterglow provide clues to conditions in the early universe. For
example, small differences in temperature across the sky show where parts of The Universe were denser, eventually condensing
into galaxies and galactic clusters.
Since the cosmic microwave background is a form of light, it exhibits all the properties of light, including polarization. On
Earth, sunlight is scattered by the atmosphere and becomes
polarized, which is why polarized sunglasses help reduce glare.
In space, the cosmic microwave background was scattered by atoms and electrons and became polarized too.
"Our team hunted for a special type of polarization called 'B-
modes,' which represents a twisting or 'curl' pattern in the polarized orientations of the ancient light," said co-leader Jamie
Bock (Caltech/JPL).
Gravitational waves squeeze space as they travel, and this
squeezing produces a distinct pattern in the cosmic microwave
SOCIETY JOURNAL, April 2014 10
background. Gravitational waves have a "handedness," much
like light waves, and can have left- and right-handed polarizations.
"The swirly B-mode pattern is a unique signature of
gravitational waves because of their handedness. This is the first
direct image of gravitational waves across the primordial sky," said co-leader Chao-Lin Kuo (Stanford/SLAC).
The team examined spatial scales on the sky spanning about
one to five degrees (two to ten times the width of the full Moon). To do this, they travelled to the South Pole to take
advantage of its cold, dry, stable air.
"The South Pole is the closest you can get to space and still be
on the ground," said Kovac. "It's one of the driest and clearest locations on Earth, perfect for observing the faint microwaves
from the Big Bang."
They were surprised to detect a B-mode polarization signal considerably stronger than many cosmologists expected. The
team analysed their data for more than three years in an effort
to rule out any errors. They also considered whether dust in our
galaxy could produce the observed pattern, but the data suggest this is highly unlikely.
"This has been like looking for a needle in a haystack, but
instead we found a crowbar," said co-leader Clem Pryke
(University of Minnesota).
When asked to comment on the implications of this discovery,
Harvard theorist Avi Loeb said, "This work offers new insights
into some of our most basic questions: Why do we exist? How did The Universe begin? These results are not only a smoking
gun for inflation, they also tell us when inflation took place and
how powerful the process was."
BICEP2 is the second stage of a coordinated program, the BICEP and Keck Array experiments, which has a co-PI structure. The
four PIs are John Kovac (Harvard), Clem Pryke (UMN), Jamie
Bock (Caltech/JPL), and Chao-Lin Kuo (Stanford/SLAC). All have worked together on the present result, along with talented
teams of students and scientists. Other major collaborating
institutions for BICEP2 include the University of California at San
Did The Universe undergo an early epoch of extremely rapid expansion? Such an inflationary epoch has been postulated to explain several puzzling cosmic attributes such as why our universe looks similar in opposite directions. Yesterday, results were released showing an expected signal of unexpected strength, bolstering a prediction of inflation that specific patterns of polarization should exist in cosmic microwave background radiation -- light emitted 13.8 billion years ago as The Universe first became transparent. Called B-mode polarizations, these early swirling patterns can be directly attributed to squeeze and stretch effects that gravitational radiation has on photon-emitting electrons. The surprising results were discovered in data from the Background Imaging of Cosmic Extragalactic Polarization 2 (BICEP2) microwave observatory near the South Pole. BICEP2 is the building-mounted dish pictured above on the left. Note how the black polarization vectors appear to swirl around the coloured temperature peaks on the inset microwave sky map. Although statistically compelling, the conclusions will likely remain controversial while confirmation attempts are made with independent observations.
11 WWW.ASTRONOMY.ORG.NZ
More Kepler Planets Confirmed From RASNZ Newsletter by Alan Gilmore
I n February NASA's Kepler mission announced the discovery of 715 new exoplanets, planets outside our
solar system. These newly-verified worlds orbit 305 stars, revealing multiple-planet systems much like our own solar
system.
Nearly 95 percent of these planets are smaller than Neptune, which is four times the diameter of Earth and 17 times Earth's mass. This discovery marks a significant increase in the number of known small-sized planets more akin to Earth than previously identified exoplanets.
Since the discovery of the first planets outside our solar system roughly two decades ago, verification has been a
laborious planet-by-planet process. Now, scientists have a statistical technique that can be applied to many planets at once when they are found in systems that harbour more than one planet around the same star.
To verify this bounty of planets, a research team co-led by Jack Lissauer, planetary scientist at NASA's Ames Research Center in Moffett Field, Calif., analysed stars with more than one potential planet, all of which were detected in
the first two years of Kepler's observations -- May 2009 to March 2011.
The research team used a technique called verification by multiplicity, which relies in part on the logic of probability. Kepler observed 150,000 stars, and has found a few thousand of those to have planet candidates. If the candidates were randomly distributed among Kepler's stars, only a handful would have more than one planet
candidate. However, Kepler observed hundreds of stars that have multiple planet candidates. Through a careful study of this sample, these 715 new planets were verified.
This method can be likened to the behaviour we know of lions and lionesses. In our imaginary savannah, the lions are the Kepler stars and the lionesses are the planet candidates. The lionesses would sometimes be observed
grouped together whereas lions tend to roam on their own. If you see two lions it could be a lion and a lioness or it could be two lions. But if more than two large felines are gathered, then it is very likely to be a lion and his pride. Thus, through multiplicity the lioness can be reliably identified in much the same way multiple planet candidates can be found around the same star.
Four years ago, Kepler began a string of announcements of first hundreds, then thousands, of planet candidates -- but they were only candidate worlds," said Lissauer. "We've now developed a process to verify multiple planet
candidates in bulk to deliver planets wholesale, and have used it to unveil a veritable bonanza of new worlds."
These multiple-planet systems are fertile grounds for studying individual planets and the configuration of planetary neighbourhoods. This provides clues to planet formation. The planets in multi-systems are small and orbit in the same plane, similar to planets in our solar system.
Four of these new planets are less than 2.5 times the size
of Earth and orbit in their sun's habitable zone, defined as the range of distance from a star where the surface temperature of an orbiting planet may be suitable for life-giving liquid water.
One of these new habitable zone planets, called Kepler-296f, orbits a star half the size and 5 percent as bright as our Sun. Kepler-296f is twice the size of Earth, but
scientists do not know whether the planet is a gaseous world, with a thick hydrogen-helium envelope, or it is a water world surrounded by a deep ocean.
This latest discovery brings the confirmed count of planets outside our solar system to nearly 1,700.
Diego, the University of British Columbia, the National Institute
of Standards and Technology, the University of Toronto, Cardiff University, Commissariat à l'Energie Atomique.
BICEP2 is funded by the National Science Foundation (NSF). NSF
also runs the South Pole Station where BICEP2 and the other
telescopes used in this work are located. The Keck Foundation
also contributed major funding for the construction of the team's telescopes. NASA, JPL, and the Moore Foundation
generously supported the development of the ultra-sensitive
detector arrays that made these measurements possible.
SOCIETY JOURNAL, April 2014 12
Standard-candle supernovae are still standard, but why?
From Science daily
S ixteen years ago two teams of supernova hunters,
one led by Saul Perlmutter of the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley
Lab), the other by Brian Schmidt of the Australian National University, declared that the expansion of The
Universe is accelerating -- a Nobel Prize-winning discovery tantamount to the discovery of dark energy. Both teams
measured how fast The Universe was expanding at different times in its history by comparing the
brightnesses and red shifts of Type Ia supernovae, the
best cosmological "standard candles."
These dazzling supernovae are remarkably similar in
brightness, given that they are the massive thermonuclear explosions of white dwarf stars, which pack roughly the
mass of our Sun into a ball the size of Earth. Based on their colours and how fast they brighten and fade away,
the brightnesses of different Type Ia supernovae can be standardized to within about 10 percent, yielding
accurate gauges for measuring cosmic distances.
Until recently, scientists thought they knew why Type Ia
supernovae are all so much alike. But their favourite
scenario was wrong.
The assumption was that carbon-oxygen white dwarf
stars, the progenitors of the supernovae, capture additional mass by stripping it from a companion star or
by merging with another white dwarf; when they approach the Chandrasekhar limit (40 percent more
massive than our Sun) they experience thermonuclear runaway. Type Ia brightnesses were so similar, scientists
thought, because the amounts of fuel and the explosion
mechanisms were always the same.
"The Chandrasekhar mass limit has long been put forward
by cosmologists as the most likely reason why Type Ia supernovae brightnesses are so uniform, and more
importantly, why they are not expected to change systematically at higher red shifts," says cosmologist Greg
Aldering, who leads the international Nearby Supernova Factory (SNfactory) based in Berkeley Lab's Physics
Division. "The Chandrasekhar limit is set by quantum mechanics and must apply equally, even for the most
distant supernovae."
But a new analysis of normal Type Ia supernovae, led by SNfactory member Richard Scalzo of the Australian
National University, a former Berkeley Lab postdoc, shows that in fact they have a range of masses. Most are near or
slightly below the Chandrasekhar mass, and about one percent somehow manage to exceed it.
The SNfactory analysis has been accepted for publication
by the Monthly Notices of the Royal Astronomical Society
and is available online as an arXiv preprint.
A new way to analyse exploding stars
While white dwarf stars are common, Scalzo says, "it's hard to get a Chandrasekhar mass of material together in
a natural way." A Type Ia starts in a two-star (or perhaps a three-star) system, because there has to be something
from which the white dwarf accumulates enough mass to explode.
Some models picture a single white dwarf borrowing mass from a giant companion. However, says Scalzo, "The most
massive newly formed carbon-oxygen white dwarfs are
expected to be around 1.2 solar masses, and to approach the Chandrasekhar limit a lot of factors would have to line
up just right even for these to accrete the remaining 0.2
Type Ia supernovae result from the explosions of white dwarf stars. These supernovae vary widely in peak brightness, how long they stay bright, and how they fade away, as the lower graph shows. Theoretical models (dashed black lines) seek to account for the differences, for example why faint supernovae fade quickly and bright supernovae fade slowly. A new analysis by the Nearby Supernova Factory indicates that when peak brightnesses are accounted for, as shown in the upper graph, the late-time behaviours of faint and bright supernovae provide solid evidence that the white dwarfs that caused the explosions had different masses, even though the resulting blasts are all “standard candles.” ... and how they fade away, as the lower graph shows. Theoretical models (dashed black lines) seek to account for the differences, for example why faint supernovae fade quickly and bright supernovae fade slowly. A new analysis by the Nearby Supernova Factory indicates that when peak brightnesses are accounted for, as shown in the upper graph, the late-time behaviours of faint and bright supernovae provide solid evidence that the white dwarfs that caused the explosions had different masses, even though the resulting blasts are all “standard candles.” Credit: Image courtesy of DOE/Lawrence Berkeley National Laboratory
13 WWW.ASTRONOMY.ORG.NZ
solar masses."
If two white dwarfs are orbiting each other they somehow have to get close enough to either collide or gently
merge, what Scalzo calls "a tortuously slow process." Because achieving a Chandrasekhar mass seems so
unlikely, and because sub-Chandrasekhar white dwarfs are so much more numerous, many recent models have
explored how a Type Ia explosion could result from a sub-Chandrasekhar mass -- so many, in fact, that Scalzo was
motivated to find a simple way to eliminate models that
couldn't work.
He and his SNfactory colleagues determined the total
energy of the spectra of 19 normal supernovae, 13 discovered by the SNfactory and six discovered by others.
All were observed by the SNfactory's unique SNIFS spectrograph (Supernova Integral Field Spectrograph) on
the University of Hawaii's 2.2-meter telescope on Mauna Kea, corrected for ultraviolet and infrared light not
observed by SNIFS.
A supernova eruption thoroughly trashes its white dwarf
progenitor, so the most practical way to tell how much
stuff was in the progenitor is by spectrographically "weighing" the leftover debris, the ejected mass. To do
this Scalzo took advantage of a supernova's layered composition.
A Type Ia's visible light is powered by radioactivity from nickel-56, made by burning carbon near the white dwarf's
centre. Just after the explosion this radiation, in the form of gamma rays, is absorbed by the outer layers --
including iron and lighter elements like silicon and
sulphur, which consequently heat up and glow in visible wavelengths.
But a month or two later, as the outer layers expand and dissipate, the gamma rays can leak out. The supernova's
maximum brightness compared to its brightness at late times depends on how much gamma radiation is absorbed
and converted to visible light -- which is determined both by the mass of nickel-56 and the mass of the other
material piled on top of it.
The SNfactory team compared masses and other factors
with light curves: the shape of the graph, whether narrow
or wide, that maps how swiftly a supernova achieves its brightest point, how bright it is, and how hastily or
languorously it fades away. The typical method of "standardizing" Type Ia supernovae is to compare their
light curves and spectra.
"The conventional wisdom holds that the light curve
width is determined primarily or exclusively by the nickel-56 mass," Scalzo says, "whereas our results show that
there must also be a deep connection with the ejected
mass, or between the ejected mass and the amount of nickel-56 created in a particular supernova."
Exploding white dwarf stars, the bottom line
Greg Aldering summarizes the most basic result of the
new analysis: "The white dwarfs exploding as Type Ia supernovae have a range of masses, and the resulting
light-curve width is directly proportional to the total mass involved in the explosion."
For a supernova whose light falls off quickly, the progenitor is a lot less massive than the Chandrasekhar
mass -- yet it's still a normal Type Ia, whose luminosity can
be confidently standardized to match other normal Type Ia supernovae.
The same is true for a Type Ia that starts from a "classic" progenitor with Chandrasekhar mass, or even more. For
the heavyweights, however, the pathway to supernova detonation must be significantly different than for lighter
progenitors. These considerations alone were enough to eliminate a number of theoretical models for Type Ia
explosions.
Carbon-oxygen white dwarfs are still key. They can't
explode on their own, so another star must provide the
trigger. For super-Chandrasekhar masses, two C-O white dwarfs could collide violently, or one could accrete mass
from a companion star in a way that causes it to spin so fast that angular momentum supports it beyond the
Chandrasekhar limit.
More relevant for cosmology, because more numerous,
are models for sub-Chandrasekhar mass. From a companion star, a C-O white dwarf could accumulate
helium, which detonates more readily than carbon -- the
result is a double detonation. Or two white dwarfs could merge. There are other surviving models, but the
psychological "safety net" that the Chandrasekhar limit once provided cosmologists has been lost. Still, says
Scalzo, the new analysis narrows the possibilities enough for theorists to match their models to observations.
"This is a significant advance in furthering Type Ia supernovae as cosmological probes for the study of dark
energy," says Aldering, "likely to lead to further
improvements in measuring distances. For instance, light-curve widths provide a measure of the range of the star
masses that are producing Type Ia supernovae at each slice in time, well back into the history of The Universe."
This work was supported by DOE's Office of Science and the Gordon and Betty Moore Foundation, and in France
by CNRS/IN2P3 (National Center for Scientific Research, National Institute of Nuclear and Particle Physics), CNRS/
INSU (CNRS National Institute for Earth Sciences and Astronomy), and PNC (Programme National de
Cosmologie).
SOCIETY JOURNAL, April 2014 14
Rare form of nitrogen detected in comet ISON From Science Daily
A team of astronomers, led by Ph.D. candidate Yoshiharu
Shinnaka and Professor Hideyo Kawakita, both from Kyoto Sangyo University, successfully observed the Comet ISON during its
bright outburst in the middle of November 2013. Subaru
Telescope's High Dispersion Spectrograph (HDS) detected two
forms of nitrogen--14NH2 and 15NH2--in the comet. This is the first time that astronomers have reported a clear detection of the
relatively rare isotope 15NH2 in a single comet and also measured
the relative abundance of two different forms of nitrogen ("nitrogen isotopic ratio") of cometary ammonia (NH3). Their results
support the hypothesis that there were two distinct reservoirs of
nitrogen the massive, dense cloud ("solar nebula") from which our
Solar System may have formed and evolved.
Why did the team focus on studying these different forms of
nitrogen in the comet? Comets are relatively small Solar System
objects composed of ice and dust, which formed 4.6 billion years ago in the solar nebula when our Solar System was in its infancy.
Because they usually reside in cold regions far from the Sun, e.g.,
the Kuiper belt and Oort cloud, they probably preserve information
about the physical and chemical conditions in the early Solar System. Different forms and abundances of the same molecule
provide information about their source and evolution. Were they
from a stellar nursery (a primordial interstellar cloud) or from a distinctive cloud (solar nebula) that may have formed our Solar
System's star, the Sun? Scientists do not yet understand very well
how cometary molecules separate into isotopes with different
abundances. Isotopes of nitrogen from ammonia (NH3) may hold the key.
Ammonia (NH3) is a particularly important molecule, because it is
the most abundant nitrogen-bearing volatile (a substance that vaporizes) in cometary ice and one of the simplest molecules in an
amino group (-NH2) closely related to life. This means that these
different forms of nitrogen could link the components of interstellar
space to life on Earth as we know it.
Since ammonia is the major carrier of nitrogen in a comet, it is
necessary to clear it from the relative abundance of its isotopes to
understand how 15NH2 separates in cometary molecules. However, the direct detection of cometary ammonia is difficult, and there are
only a few reports of its clear detection. Therefore, the team
concentrated on studying the form of NH2 developed after the ammonia was broken down by the light ("photodissociation") in
the cometary coma. The team was fortunate to observe the comet
as it neared the Sun, when its icy composition was evaporating.
They were also fortunate that NH2, a derivative of ammonia (NH3), is easy to observe in the optical wavelength, and the relative
abundance of nitrogen isotopes of cometary ammonia is probably
close to that of NH2.
The team used Subaru Telescope's HDS to successfully observe
Comet ISON on November 15th and 16th when the comet had its
bright outburst that began on November 14th. The observation
clearly detected 15NH2 from Comet ISON, and the team inferred that
the ratio of cometary ammonia of 14N/15N (139±38) is consistent
with the average (14N/15N~130) of that from the spectra of 12 other comets. In other words, Comet ISON is typical in its relative
abundance of 14N/15N in cometary ammonia.
These findings support the hypothesis that there were two distinct reservoirs of nitrogen in the solar nebula: 1) primordial N2 gas
having a protosolar value of 14N/15N, and 2) less volatile and
probably solid molecules having a ratio of about 14N/15N~150 in the
solar nebula. In the case of a dense molecular cloud core, the isotopic ratio of hydrogen cyanide (HCN) is similar to that of comets
while its ratio in ammonia is different from its cometary value.
This may mean that the ammonia formed in an environment of a low temperature dust surface, not in the gas of the molecular
cloud. Laboratory experiments show that various complex molecules
can form on the surface of low temperature dust. If the ammonia molecule formed on the low temperature dust surface, the
cometary nucleus could contain a complex molecule that relates to
the origin of life, in addition to the ammonia. If this is so, it raises
the possibility that the comet brought these materials to Earth.
In the future, the team would like to increase the sample of comets
for which nitrogen isotopic ratios of cometary ammonia have been
determined. They would also like to carry out laboratory measurements of 15NH2 to obtain more precise isotopic ratios. On a
larger scale, the team hopes to investigate the origin of Comet
ISON and the mechanisms that triggered its outburst so that we can
better understand the evolution of the Solar System.
Close-up of spectra of NH2 emission lines (of the same transitions for both 14NH2 and 15NH2) in Comet ISON, showing the difference in wavelengths and relative intensity between the isotopes. The red and green-dashed lines indicate the observed spectrum. The blue line indicates 15NH2, clearly detected for the first time. Credit: Image courtesy of National Astronomical Observatory of Japan
15 WWW.ASTRONOMY.ORG.NZ
Society Telescopes for Hire The Society has a wide range of telescopes for hire to members.
If you are looking to purchase or upgrade a telescope and are not sure what to buy, this is a very good way to evaluate some of the available equipment. See also the advertisement on the back page. The society does, of course ,have more telescopes and other equipment, and you will start to see this equipment being made available to members as rental gear; including some equipment more suited for experienced members as well as beginners.
Three items that are now newly available for rental include:
• Celestron C5 5" SCT on iOptron Minitower Computerised GoTo mount
• Celestron Nexstar5 5” SCT on a computerised GoTo Alt/Az mount with tripod
• Meade 90mm Achromatic Refractor on a manual Equatorial Mount.
If you have a project idea where this telescope or other society equipment may help, particularly if you are happy to write a short article for the journal, please see Steve or Graham.
The society is also keen to hear what members would like to have available for rental (the availability of the C5 scopes is in response to a member request for a more portable rental option). Any submissions and ideas, or any questions or queries regarding rental equipment should go to Rental Coordinator, Steve Hennerley at [email protected] or on 027 245 6441
Explanation: What is creating the gamma rays at the centre of our Galaxy? Excitement is building that one answer is elusive dark matter. Over the past few years the orbiting Fermi Gamma-ray Space Telescope has been imaging our Galaxy's centre in gamma-rays. Repeated detailed analyses indicate that the region surrounding the Galactic centre seems too bright to be accounted by known gamma-ray sources. A raw image of the Galactic Centre region in gamma-rays is shown above on the left, while the image on the right has all known sources
subtracted -- leaving an unexpected excess. An exciting hypothetical model that seems to fit the excess involves a type of dark matter known as WIMPs, which may be colliding with themselves to create the detected gamma-rays. This hypothesis is controversial, however, and debate and more detailed investigations are ongoing. Finding the nature of dark matter is one of the great quests of modern science, as previously this unusual type of cosmologically pervasive matter has shown itself only through gravitation. Image Credit: T. Daylan et al., Fermi
Gamma Rays from Galactic Centre Dark Matter?
SOCIETY JOURNAL, April 2014 16
Jupiter is the 'evening star', the first seen after sunset. It is in the northwest and sets around 10:30 pm NZST. A small telescope will show the disk of Jupiter and its four bright 'Galilean' moons: the Moons discovered by Galileo in 1610. Jupiter is 800 million km away.
Mars is a bright orange-red 'star' in the northeast sky at dusk. By midnight it is due north, halfway up the north sky. Mars is at its closest in mid-April, but still 93 million km away so is small in a telescope. Magnified 120 times it will appear as big as the full Moon does to the naked eye. Right of Mars is bluish-white Spica, the brightest star in Virgo. Later in the evening the bright orange star Arcturus (not shown on the chart) rises in the northeast. It twinkles more than Mars, as stars do, often flashing red and green.
Saturn is near the eastern skyline, a little south of due east at dusk. It is a lone bright 'star', shining with a creamy tint. Well to its right is orange Antares, the heart of Scorpius. A small telescope shows Saturn as an oval, the rings and planet blended. Larger telescopes separate the planet and rings and show Saturn's moons looking like faint stars close to the planet. Titan is the biggest moon, appearing four ring-diameters from the planet. It takes two weeks to complete an orbit. Saturn is 1350 million km away. The full Moon will be just below Saturn on the 17th.
On April 15 there is a total lunar eclipse. It is ideally timed for New Zealand. The Moon is entering the penumbra, the outer part of Earth's shadow, around the time it rises, at sunset. So it will look darker on its lower edge. It then slowly darkens all over as it moves into the centre part of Earth's shadow, the umbra. By 7:07 pm it will be fully in the umbra. It begins to emerge from the umbra at 08:25 and is fully out by 9:33. By 10:38 it is completely clear of Earth's shadow.
Sirius is the first true star to appear at dusk, midway down the northwest sky. It is soon followed by Canopus, southwest of the zenith. Below Sirius are Rigel and Betelgeuse, the brightest stars in Orion. Between them is a line of three stars: Orion's belt. To southern hemisphere star watchers, the line of three makes the bottom of 'The Pot', now tipped on its side. Below and right of Sirius is Procyon.
Low in the north are Pollux and Castor, the heads of Gemini the twins, making a vertical pair. Above and right of them is a fuzzy patch of light, the Praesepe cluster, marking the shell of Cancer the crab. Praesepe is also called the Beehive cluster, the reason obvious when it is viewed in binoculars.
Crux, the Southern Cross, is high in the southeast. Below it, and brighter, are Beta and Alpha Centauri, often called 'The Pointers'. Alpha Centauri is the closest naked-eye star, 4.3 light years (l.y)* away. Beta Centauri, like most of the stars in Crux, is a blue-giant star hundreds of l.y. away. Canopus is also a very luminous distant star; 13 000 times brighter than the Sun and 300 l.y. away.
The Milky Way is brightest in the southeast above Crux. The Milky Way can be traced to nearly overhead where it fades. It becomes very faint in the northwest, right of Orion. The Milky Way is our edgewise view of the galaxy, the pancake of billions of stars of which the Sun is just one.
The Clouds of Magellan, LMC and SMC are midway down the southwest sky, easily seen by eye on a dark moonless night. They are two small galaxies about 160 000 and 200 000 light years away.
Venus (not shown) is the brilliant 'morning star'. It rises around 3 a.m. NZST at the beginning of the month. It slips lower, rising around 3:40 at the end of April. In a telescope it gets smaller and more gibbous (full) as it moves to the other side of the Sun. It is 130 million km away mid month.
Mercury (not shown) ends a morning sky appearance. It rises due east about 5 a.m. at the beginning of the month; a lone bright star. Through April it sinks into the dawn twilight as it moves to the far side of the Sun. It is tiny in a telescope; 1/3rd the size of Mars. It is 140 million km away in mid April.
*A light year (l.y.)is the distance that light travels in one year: nearly 10 million million km or 1013 km. Sunlight takes eight minutes to get here; moonlight about one second. Sunlight reaches Neptune, the outermost major planet, in four hours. It takes four years to reach the nearest star, Alpha Centauri.
The Evening Sky in April 2014 By Alan Gilmore
SOCIETY JOURNAL, April 2014 18
Library Corner With Tony Reynolds
The following titles have been recently added to the library.
Observing the Sun with Coronado Telescopes Phillip Pugh
The advent of the Coronado PST means that today’s amateur solar observers can see – and image – sunspots, flares, prominences, filaments, and active regions of the Sun, all in amazing detail.
Getting the very best out of a Coronado solar telescope still requires knowledge of specialist techniques and an accumulation of experience, which are what this book provides
Catalogue section: QB88
The Great Melbourne Telescope Richard Gillespie
One of the hidden treasures of 19th century Australia, this book covers the history of this great telescope and its role within Melbourne. Thanks to Jill for donating this book.
Catalogue section: QB81
Spectroscopy: the Key to the Stars Keith Robinson
Any amateur astronomer who carries out (or who is interested in) observational spectroscopy and who wants a non-technical account of the physical processes which determine the intensity and profile morphology of lines in stellar spectra will find this is the only book written specially for them. And of course, "armchair astronomers" who simply want to understand the physical processes which shape lines in stellar spectra will find this book equally fascinating.
Catalogue section: QB465
Using Commercial Amateur Astronomical Spectrographs Jeffery L. Hopkins
This book provides detailed information about how to get started inexpensively with low-resolution spectroscopy, and then how to move on to more advanced high-resolution spectroscopy. Uniquely, the instructions concentrate very much on the practical aspects of using commercially-available spectroscopes, rather than simply explaining how
spectroscopes work.
Catalogue section: QB465
Featured Section – QB465 Spectroscopy This section now contains modern titles from the Patrick Moore astronomy series covering both practical and theoretical aspects of
amateur spectroscopy in some detail.
Great if you're actively taking measurements of the stars or simply into spectrums
19 WWW.ASTRONOMY.ORG.NZ
Auckland Astronomical Society Inc, P O Box 24-187, Royal Oak,
Auckland 1345, New Zealand
Email [email protected]
Journal [email protected]
Website www.astronomy.org.nz facebook.com/AuckAstroSoc
Membership inquiries contact Andrew Buckingham at [email protected] or by phone on (09)-473-5877 or by mobile on 027-246-2446
Society Contacts
President Grant Christie (021) 024 04992
Vice-President Bill Thomas (09) 478 4874
Treasurer & Andrew Buckingham (09) 473 5877 Membership
Secretary Kleo Zois 022 691 2055
Curator of Graham Beazley (09) 537 1313 Instruments
Telescope Hire Steve Hennerley 027 245 6441
Librarian Tony Reynolds (09) 480 8607
Journal Editors Clive Bolt (09) 534 946
Shaun Fletcher (09) 480 5648
Milina Ristic 029 912 4748
Council Gavin Logan (09) 820 6001
Council Bernie Brenner 09) 445 3293
Council David Britten (09) 846 3657
Council Oana Jones 021 236 2962
The 2013 Council
Solar System Events April 2014 From the RASNZ Website
• apogee: Furthest point in the orbit of a body orbiting the Earth
• conjunction: Two astronomical objects are 'lined up' (have the same right ascension) when viewed from Earth
• declination: 'Latitude' for celestial objects. The distance in degrees above (north) or below (south) the celestial equator. • perigee: Nearest point in the orbit of a body orbiting the Earth
April 2 Uranus at conjunction
April 4 Aldebaran 2.0 degrees south of the Moon
April 5 Moon northern most declination (19.0 degrees)
April 6 Jupiter 5.3 degrees north of the Moon
April 7 Moon first quarter
April 8 Moon at apogee Mars at opposition
April 10 Regulus 4.9 degrees north of the Moon
April 12 Venus 0.7 degrees north of Neptune
April 14 Mars nearest to Earth Mars 3.3 degrees north of the Moon Mercury 1.2 degrees south of Uranus
April 15 Pluto stationary Spica 1.7 degrees south of the Moon Moon full Eclipse
April 17 Saturn 0.4 degrees north of the Moon Occn
April 19 Moon southern most declination (-19.0 degrees)
April 21 Pluto 2.4 degrees south of the Moon
April 22 Moon last quarter
April 23 Moon at perigee
April 24 Neptune 4.8 degrees south of the Moon
April 25 Venus 4.1 degrees south of the Moon
April 26 Mercury superior conjunction
April 27 Uranus 1.9 degrees south of the Moon
April 29 Moon new Eclipse Mercury 1.6 degrees north of the Moon