Observation and analysis of the youngest transiting planet candidate

Stefanie RätzResearch Fellow, ESA, ESTEC, Noordwijk, The Netherlands

YETI – Young Exoplanet Transit InitiativeSearch for transiting planets in young open clusters

• Main goal: Search for close-in, young planets and Brown Dwarfs with the transit method

• Young, open star clusters provide an ideal environment because they have a relatively high number of stars of same age, metallicity and distance

• Can give constraints on:– Limits for time scales of planet formation and migration– Effect of age, environment and metallicity on frequency of planets– Evolutionary models of planets and Brown Dwarfs

• Additional scientific output:– Constraints on Metallicity, age, distance– Large number of variable stars could be analyzed

• Different clusters in a range of 1-200 Myr were selected

Neuhäuser et. al. (2011)

Transit Observation

• we launched an international observing campaign

• Strategy: collecting data from 0.6 - 2.6-m telescopes spread worldwide at different longitudes

Aim: Observations 24/7

• three runs per year per cluster in two or three subsequent years: typically one to two weeks long

Gunma

Astronomical Observatory1.5-m telescope

Xinglong

Observatory90/60 cm

Byurakan

1.0 and 2.6 telescopes

Stara Lesna

Astronomical Institute0.6-m telescope

Jena

Astrophysical Institute0.9/0.6-m telescope

Sierra Nevada

1.5-m telescope

Gettysburg

Collage Observatory0.4-m telescope

Llano del Hato Observatory

1-m Schmidt telescope

Tenagra II

0.8-m telescope

Stony Brook

14““ telescope

Lulin

Lulin Observatory1m Telescope

Nainital

State Observatory1-m telescope

Rozhen

0.6 and 2-m telescopes

Torun

60 cm telescope

Calar Alto

2.2-m telescope

Swarthmore

0.6-m telescope

Observatorio Cerro Armazones

two 5.9’’ telescopes

Mauna Kea

Univ. of Hawaii2.2m telescope

25 Ori cluster(Briceño et al. 2007)

• Well defined group of at least 200 low-mass pre-main-sequence stars

• Concentrated within ~1° of the early-B star 25 Ori in Orion OB1a

• The parallaxes of the Hipparcos stars yield a mean distance of 323 pc

• Low mass members follow a well- defined band in the color-magnitude

Diagram isochronal age ~7-10 Myrs

• disk lifetime: ~ 5 -10 Myrs, hence 25 Ori cluster at the very age, when planet formation finishes

• Most populated cluster in this age range known within 500 pc

excellent laboratory to study the early evolution of sun-like stars, protoplanetary disks, and planet formation

3 Myrs

10 Myrs

1 Myr

30 Myrs100 Myrs

Observations

• Start of the monitoring of 25 Ori: January 2010– Observations from three different Observatories beginning of 2010– University Observatory Jena: 15 nights

• Season 1 (winter 2010/2011):– 2010 Dec. 10 – 17, 2011 Jan. 14 – 24, 2011 Feb. 16 – 28

– Observations from 13 different Observatories

– University Observatory Jena: 52 nights

• Season 2 (winter 2011/2012 ):– 2011 Dec. 05 – 16, 2012 Jan. 09 – 18, 2012 Jan. 31– Feb. 09

– Observations from 12 different Observatories

– University Observatory Jena: 42 nights

• Season 3 (winter 2011/2012 ):– 2012 Dec. 04 – 14, 2013 Jan. 08 – 18, 2013 Feb. 10 – 17

– Observations from 7 different Observatories

– University Observatory Jena: 5 nights

Duty Cycle: 54.5%

First Transit candidate

Barnes et al. 2013

Observations

• Start of the monitoring of 25 Ori: January 2010

• Season 1 (winter 2010/2011): 52 clear nights including 13 transits

• Season 2 (winter 2011/2012): 42 clear nights including 11 transits

• Season 3 (winter 2012/2013): only 5 observing nights

• Follow-up observations on the Observatorio de Sierra Nevada, Spain

– 5 transit observations in 2013 Nov-Dec

• After each season all transits were combined

Barnes et al. 2013:

a precessing planet transiting a gravity-darkened star

GravityDarkening

Fast rotation star is oblate (larger radius at the equator than at the poles) poles have a higher surface gravity, and thus, higher temperature and brightness

Outlook

Gaps in the observations were interpolated with 3rd order polynomials (continuity of the data points)

before

see Poster M. Kitze (EP-5)

Thank you for your attention !!!