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![Page 1: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/1.jpg)
![Page 2: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/2.jpg)
The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era.
Guillem Anglada-Escude (1,2)Alan P. Boss(1)
Alycia Weinberger (1)Ian Thompson (1)
(1)Carnegie Institution for Science(2) Institute for Astrophysics - University of Goettingen
![Page 3: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/3.jpg)
Astrometry and radial velocity methods
K
Time
RV
a
![Page 4: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/4.jpg)
1º
3474 km
1’
120 km
1/60
1/60
1’’
2 km
1/1000
2 m
1 mas
2 cm
10 mas1/100
1 mas
A closer look at astrometry…
![Page 5: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/5.jpg)
Astrometric recipes
masM
M
d
R
m
msun
pc
AU
jup
p *
Exo-Jupiter formula
3*M
M
d
R
m
mas sun
pc
AU
Earth
p
Exo-Earth formula
G dwarf @ 10 pc
M dwarf @ 10 pc
0.1 mas 1.0 masMan on
the moonBook on
the moon
3 mas0.3 masPaper
width on the moon
Euro width on the moon
Gaia/ESA Ground based
![Page 6: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/6.jpg)
Ground based AstrometryWhy M dwarfs?
Numerous
Faint
Low mass
Poorly characterized
Hosts to habitable planets (that can be
detected)
![Page 7: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/7.jpg)
Alan Boss (PI, DTM/CIW)Alycia Weinberger (DTM/CIW)Ian Thompson (OCIW)Chistoph Brik (OCIW)Greg Burley (OCIW)
2.5m duPont Telescope. Las Campanas Observatory, Chile
Follow-up a sample of 120 M, L and T dwarfs
Carnegie Astrometric planet Search
![Page 8: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/8.jpg)
Carnegie Astrometric planet Search
CAPScam (I band), 2048x2048
![Page 9: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/9.jpg)
Classic local astrometry
Input catalog Extract, centroid and crossmatch the sources
Fit field distortions Shift (2 par)rotation, scale (4 par)Quadratic deformations (6 para)
Obtain a new catalog
Iterate
![Page 10: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/10.jpg)
CAPS pipeline : ATPa software
If you are interested in testing with your own images, please check http://www.dtm.ciw.edu/anglada/
•Fully coded in Java (run on your computer)
•Graphic User Interface
•One night processing and Astrometric Iterative solution
• Final Data products : catalog, maps of extracted sources, reference stars, motion of each star, etc.
It also has a Manual!
![Page 11: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/11.jpg)
Carnegie Astrometric Planet search : Lots of parallaxes of cool dwarfs
200+ new and updated parallaxes
![Page 12: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/12.jpg)
Carnegie Astrometric Planet Search program so far…
• Astrometric detection needs long time baselines (5-10 yr)
• Overall precision better than 1 mas/epoch.
• Almost 4 years of baseline, Gas giants should be detected soon (if present)
• About 120 M dwarfs
![Page 13: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/13.jpg)
Carnegie Astrometric Planet Search… candidates?
brown dwarfs
gas giant planets
0.25 milliarcsec accuracy, S/N = 4
0.1HZ
0.5 HZ
![Page 14: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/14.jpg)
GJ 317 GJ 1214VB 10
Astrometric detectionPravdo & Shaklan 2010 ApJ
P=270 daysM ~ 6 Mjup
D = 7 pc
Galactic plane
Doppler candidateJohnson et al 2007, ApJ
P=690 daysM sin i ~ 2 Mjup
D = 9.6 pc
[Fe/H] = -0.3??
Transit + Doppler planetCharbonneau et al. 2009, Nat
P=1.83 daysM sin i ~ 6 Meartj
D = 12.0 pc
Radius 15% larger??
Lessons learned from individual targets
? ? ?
![Page 15: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/15.jpg)
Lessons learned from individual targets : VB 10
Black & Scargle 1982
Astrometry2 x offsets 2 x Proper motions 1 x Parallax
HD 125612Fischer et al. 2007
Doppler1xoffset
GJ 317, Anglada-Escude et al. 2012
![Page 16: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/16.jpg)
Lessons learned from individual targets : VB 10
Pravdo & Shaklan ApJ, 2009
Residual periodograms
Astrometric periodograms
K = 1500 m/sK = 3000 m/s
Anglada-Escude et al. ApJ, 2011
![Page 17: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/17.jpg)
Anglada-Escude et al. ApJ 2011, RV follow-up with MIKE/MagellanBean et al. 2011, RV follow-up with CRIRES/VLT
Lazorenko et al. 2011, Astrometric follow-up
Lessons learned from individual targets : VB 10
49.9 days 270 days
![Page 18: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/18.jpg)
Lessons learned from individual targets
GJ 317 GJ 1214VB 10
Astrometric detectionPravdo & Shaklan 2010 ApJ
P=270 daysM ~ 6 Mjup
D = 7 pc
Galactic plane
Doppler candidateJohnson et al 2007, ApJ
P=690 daysM sin i ~ 2 Mjup
D = 9.6 pc
[Fe/H] = -0.3??
Transit + Doppler planetCharbonneau et al. 2009, Nat
P=1.83 daysM sin i ~ 6 Meartj
D = 12.0 pc
Radius 15% larger??
Astrometric periodograms
(need better understanding of sampling)
![Page 19: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/19.jpg)
d = 9.6 pcM* = 0.24 Msun
M sin i = 1.85 Mjup
P = 692 days, a = 0.95 AU
masM
M
d
R
m
msun
pc
AU
jup
p *
Exo-Jupiter formula
0.78 mas
Jonhson, Butler et al. ApJ 2007
Lessons learned from individual targets : GJ 317
![Page 20: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/20.jpg)
d = 14.9 pc0.32 mas M* = 0.42 Msun
M sin i = 1.8 Mjup
P = 692 days a = 0.95 AU
d = 9.6 pca =0.78 mas
Lessons learned from individual targets : GJ 317
![Page 21: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/21.jpg)
𝒗 𝒓 (𝒕)=𝜸+𝑲 ¿𝑿 (𝒕)=𝑿𝟎+𝝁𝜶 (𝒕− 𝒕𝟎 )+∆𝜶 (𝒕)−𝝅𝒙𝒐𝒃𝒔 ∙ �̂�𝜶𝑨𝑼
𝒀 (𝒕)=𝒀 𝟎+𝝁𝜹 (𝒕− 𝒕𝟎 )+∆𝜹 (𝒕 )−𝝅𝒙𝒐𝒃𝒔 ∙ �̂�𝜹𝑨𝑼
Lessons learned from individual targets : GJ 317
![Page 22: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/22.jpg)
𝐿∝𝐸𝑋𝑃 [− 12𝜒2]
Likelihood function
Period
Mas
sLessons learned from individual targets : GJ 317
![Page 23: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/23.jpg)
𝐿∝𝐸𝑋𝑃 [− 12𝜒2]
Likelihood function
Period
Mas
s
Provides optimal sampling in highly dimensional spaces
N = 13
Run a few million steps and you are done!
Lessons learned from individual targets : GJ 317
![Page 24: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/24.jpg)
Lessons learned from individual targets : GJ 317
![Page 25: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/25.jpg)
First exoplanet “confirmed” with Ground based astrometry!
Lessons learned from individual targets : GJ 317
![Page 26: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/26.jpg)
Lessons learned from individual targets
GJ 317 GJ 1214
Doppler candidateJohnson et al 2007, ApJ
P=690 daysM sin i ~ 2 Mjup
D = 9.6 pc
[Fe/H] = -0.3??
Transit + Doppler planetCharbonneau et al. 2009, Nat
P=1.83 daysM sin i ~ 6 Meartj
D = 12.0 pc
Radius 15% larger??
VB 10
Astrometric detectionPravdo & Shaklan 2010 ApJ
P=270 daysM ~ 6 Mjup
D = 7 pc
Galactic plane
Astrometric periodograms
(need better understanding of sampling)
![Page 27: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/27.jpg)
Lessons learned from individual targets
GJ 317 GJ 1214VB 10
Astrometric detectionPravdo & Shaklan 2010 ApJ
P=270 daysM ~ 6 Mjup
D = 7 pc
Galactic plane
Doppler candidateJohnson et al 2007, ApJ
P=690 daysM sin i ~ 2 Mjup
D = 9.6 pc
[Fe/H] = -0.3??
Transit + Doppler planetCharbonneau et al. 2009, Nat
P=1.83 daysM sin i ~ 6 Meartj
D = 12.0 pc
Radius 15% larger??
Combine RV+Astrometry
Astrometric periodograms
(need better understanding of sampling)
![Page 28: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/28.jpg)
Lessons learned from individual targets : GJ 1214
CAPS Astrometry (new)RMS < 1.0 mas
HARPS-TERRA RVs (updated)
30 transit times and updated
Transit observablesSada et al, 2010, Carter et al. 2011, Kundurthy et al., 2011
• K band, low res(new)• 4 Optical bands• 3x2MASS bands• 4xWISE bands (new)
![Page 29: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/29.jpg)
Lessons learned from individual targets : GJ 1214
d
M*
L*
Teff
14.47 (0.14) pc
0.175 (0.009) Ms
3.9 10-3 Ls
3200 K
12.9 (1.0) pc
0.155 Ms
3.3 10-3Ls
2900 K
+12%+13%
+19%+10%
Previous NEW!
![Page 30: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/30.jpg)
Lessons learned from individual targets : GJ 1214
![Page 31: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/31.jpg)
Lessons learned from individual targets : GJ 1214
![Page 32: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/32.jpg)
Lessons learned from individual targets
GJ 317 GJ 1214VB 10
Astrometric detectionPravdo & Shaklan 2010 ApJ
P=270 daysM ~ 6 Mjup
D = 7 pc
Galactic plane
Doppler candidateJohnson et al 2007, ApJ
P=690 daysM sin i ~ 2 Mjup
D = 9.6 pc
[Fe/H] = -0.3??
Transit + Doppler planetCharbonneau et al. 2009, Nat
P=1.83 daysM sin i ~ 6 Meartj
D = 12.0 pc
Radius 15% larger??
Combine RV+Astrometry
Astrometric periodograms
(need better understanding of sampling)
![Page 33: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/33.jpg)
Lessons learned from individual targets
GJ 317 GJ 1214VB 10
Astrometric detectionPravdo & Shaklan 2010 ApJ
P=270 daysM ~ 6 Mjup
D = 7 pc
Galactic plane
Doppler candidateJohnson et al 2007, ApJ
P=690 daysM sin i ~ 2 Mjup
D = 9.6 pc
[Fe/H] = -0.3??
Transit + Doppler planetCharbonneau et al. 2009, Nat
P=1.85 daysM sin i ~ 6 Meartj
D = 14.5 pc
Everything is good!
Combine RV+Astrometry
Transits+RV, astrometry
Simultaneous FIT!
Astrometric periodograms
(need better understanding of sampling)
![Page 34: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/34.jpg)
‘Other’ exoplanet related programs… 10 years before Gaia
Young field M dwarfs (UV and X ray sources) from Shkolnik et al. 2009 ApJ
12 New members to nearby young moving groups (Beta Pictoris 10 Myr, AB Dor 40 Myr)
61 new parallaxes!
Shkonlik, Anglada-Escude, Weinberger, Boss et al. 2011 (to be submitted!)
Based on astrometry obtained with ATPa (just accepted for publication, ApJ)
J. O’Faherty PhD. Thesis
![Page 35: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/35.jpg)
Early L brown dwarf at 12 pc
![Page 36: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/36.jpg)
Early L brown dwarf at 12 pc
![Page 37: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/37.jpg)
Synergies?
The obvious…
• Combine with ground based observations
• Targeted follow-up of peculiar systems
• Extend time baselines
![Page 38: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/38.jpg)
How you do that???
𝒗 𝑯𝑰𝑹𝑬𝑺(𝒕)=𝜸𝟏+𝑲 ¿
𝒗 𝑯𝑨𝑹𝑷𝑺(𝒕)=𝜸𝟐+𝑲 ¿
𝒖 (𝒕 )=𝒖𝟎+𝝁 ′𝜶 (𝒕−𝒕𝟎 )−𝝅𝒙𝒐𝒃𝒔 ∙ �̂�𝜶𝑨𝑼
+∆𝜶 (𝒕)
v
𝒓=¿(�⃗�−�⃗�𝟎) �⃗�>¿
Gai
a
𝑿 (𝒕 )=𝑿𝟎+𝝁𝜶 (𝒕−𝒕𝟎)−𝝅�⃗�𝒐𝒃𝒔 ∙ �̂�𝜶𝑨𝑼
+∆𝜶 (𝒕)
𝒀 (𝒕)=𝒀 𝟎+𝝁𝜹 (𝒕−𝒕𝟎 )−𝝅𝒙𝒐𝒃𝒔 ∙ �̂�𝜹𝑨𝑼
+∆𝜹 (𝒕 )
CAPS
DopplerM
CMC
![Page 39: The Carnegie Astrometric Planet Search and the role of ground based astrometry in the pre-Gaia era. Guillem Anglada-Escude (1,2) Alan P. Boss(1) Alycia.](https://reader030.fdocuments.in/reader030/viewer/2022032722/56649ce05503460f949a99be/html5/thumbnails/39.jpg)
How you do that???
𝒗 𝑯𝑰𝑹𝑬𝑺(𝒕)=𝜸𝟏+𝑲 ¿
𝒗 𝑯𝑨𝑹𝑷𝑺(𝒕)=𝜸𝟐+𝑲 ¿
𝒖 (𝒕 )=𝒖𝟎+𝝁 ′𝜶 (𝒕−𝒕𝟎 )−𝝅𝒙𝒐𝒃𝒔 ∙ �̂�𝜶𝑨𝑼
+∆𝜶 (𝒕)
v
𝒓=¿(�⃗�−�⃗�𝟎) �⃗�>¿
Gai
a
𝑿 (𝒕 )=𝑿𝟎+𝝁𝜶 (𝒕−𝒕𝟎)−𝝅�⃗�𝒐𝒃𝒔 ∙ �̂�𝜶𝑨𝑼
+∆𝜶 (𝒕)
𝒀 (𝒕)=𝒀 𝟎+𝝁𝜹 (𝒕−𝒕𝟎 )−𝝅𝒙𝒐𝒃𝒔 ∙ �̂�𝜹𝑨𝑼
+∆𝜹 (𝒕 )
CAPS
DopplerM
CMC
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𝑿 (𝒕 )=𝑿𝟎+𝝁𝜶 (𝒕−𝒕𝟎)−𝝅𝒑 (𝒕 )+𝑨𝒄𝒐𝒔 (𝒘𝒕 )+𝑩𝒔𝒊𝒏 (𝒘𝒕 )
𝒀 (𝒕 )=𝒀 𝟎+𝝁𝜹 (𝒕− 𝒕𝟎 )−𝝅𝒒(𝒕 )+𝑪𝒄𝒐𝒔 (𝒘𝒕 )+𝑫𝒔𝒊𝒏(𝒘𝒕 )
Astrometric model is LINEAR in the relevant quantities
Only becomes (a bit) more complicate when combined with RVs, or for highly eccentric orbits (e>0.6)
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Conclusions
Experience : As ground based transit surveys did for COROT & Kepler… prepares the tools, identifies pitfalls
Cool parallaxes NOW : Ground based astrometry, gives your parallaxes NOW at sufficient accuracy (nearby cool stars)
When Gaia data is released (residuals, not solutions!) …
• Combine astrometric solutions• Time to pack (at least CAPS, RECONS and a few others)• … work continues on L, T and Y dwarfs! (nIR astrometry)
First population statistics of ‘long period’ Gas giants around M dwarfs available before Gaia