Discovery of a planet by astrometry

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Discovery of a planet by astrometry

Post by Lazarus on 28th May 2009, 4:53 pm

Say hello to VB 10b, the first exoplanet discovered by astrometry. Six times the mass of Jupiter around a tiny star, have fun with the planet formation theories...
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Re: Discovery of a planet by astrometry

Post by youknowandy on 29th May 2009, 1:57 am

It's really, really the first planet discovered by astrometry? They actually decided to declare such a planetary discovery confirmed. I'm still bitter about that one Lalande system never being confirmed. But wow. That's good news for people like me who like to hear about new planets that are close to the sun. 20 light years for this one, not bad. I hope they accellerate the number of planets confirmed in this manner.
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Re: Discovery of a planet by astrometry

Post by Borislav on 29th May 2009, 5:28 am

may 2008
exep.jpl.nasa.gov/ExoplanetForumFiles/04-5_Pravdo_astrometrysp.pdf


http://www.palomar.caltech.edu:8000/instruments/abstracts.tcl?run_id=2201
Proposal#: P-13
Title: Sub-Jupiter Mass Planets
Abstract: Continuation of an NGS AO astrometric exoplanet survey sensitive to sub-Jupiter-mass planets around mid-M-dwarfs.

http://www.palomar.caltech.edu:8000/instruments/abstracts.tcl?run_id=2196
Confirmation of a G218-020 Planet

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Re: Discovery of a planet by astrometry

Post by Edasich on 29th May 2009, 6:11 am

Finally something awesome Very Happy

Plus, I add this other article:

http://www.space.com/scienceastronomy/090528-exoplanet-small-star.html
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Re: Discovery of a planet by astrometry

Post by Borislav on 29th May 2009, 6:39 am

STEPS Targets
http://steps.jpl.nasa.gov/links/docs/stepswhitepaper.pdf

http://www.solstation.com/stars/wolf1055.htm
VB 10 = Gliese 752 = Wolf 1055

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Re: Discovery of a planet by astrometry

Post by Sirius_Alpha on 29th May 2009, 8:37 am

So, we have a planet orbiting Van Biesbroek's Star. Isn't this an eclipsing binary system? Solstation also claims it is.

It would be interesting to catch VB 10 b transiting the other star in the system, which if the system is truly an eclipsing binary, should happen occasionally.

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Re: Discovery of a planet by astrometry

Post by Lazarus on 29th May 2009, 1:20 pm

SIMBAD lists GJ 752 as an eclipsing binary, however the two components (GJ 752A and GJ 752B=VB 10) have a separation of 74.72 arcseconds which corresponds to a projected separation of about 440 AU using the revised Hipparcos parallax of 170.36 mas for GJ 752A. Neither of the individual components is listed as being an eclipsing binary though.
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Re: Discovery of a planet by astrometry

Post by Borislav on 29th May 2009, 2:29 pm

http://steps.jpl.nasa.gov/links/docs/pravdoshaklan09vb10b.pdf

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Re: Discovery of a planet by astrometry

Post by Lazarus on 29th May 2009, 2:39 pm

How exactly did you find that link? My (admittedly quick) search of the STEPS website didn't show that paper available from the main site... it's not on their publication list for example.
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Re: Discovery of a planet by astrometry

Post by Borislav on 29th May 2009, 2:57 pm

Link
http://steps.jpl.nasa.gov/news/news_052809.html

http://steps.jpl.nasa.gov/
update

STEPS has made the first astrometric discovery of an exoplanet. The planet is called VB 10b and the star, VB 10, is one of the smallest known, just above the boundary separating low-mass stars and brown dwarfs. Read the preprint about this unique planet by following the links under 05.28.2009 on the right.

STEPS has discovered 5 low-mass companions to M-dwarfs that were previously believed to be single (see references). The companions are brown dwarfs or late M dwarfs. The dynamical measurements of the masses of all the components add to the currently scarce knowledge of such masses. Other candidate companions that are extrasolar giant planets (EGPs) can be confirmed with further STEPS observations. One of these would be the first astrometrically discovered EGP

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Re: Discovery of a planet by astrometry

Post by Lazarus on 29th May 2009, 3:04 pm

Ok, no worries.
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Re: Discovery of a planet by astrometry

Post by Edasich on 30th May 2009, 7:36 am

EPE lists this old article in the bibliography:

http://adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1983AJ.....88.1038H&db_key=AST&link_type=ABSTRACT&high=43f438855e18572

Should we revisit VB8's inferred planetary companion now?
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Re: Discovery of a planet by astrometry

Post by Borislav on 30th May 2009, 9:39 am

http://steps.jpl.nasa.gov/links/docs/pravdoshaklan09vb10b.pdf
A report of a planetary companion to VB 10 (Harrington, Kallarkal, & Dahn 1983) was later ruled out by subsequent observations (Monet et al. 1992, Harrington et al. 1993).

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Re: Discovery of a planet by astrometry

Post by Lazarus on 30th May 2009, 9:50 am

Another good thing about this discovery is that it provides a test for developing instruments to measure high precision radial velocities for such red stars, which are brightest in the infrared. Current RV techniques work in the optical region of the spectrum.
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Re: Discovery of a planet by astrometry

Post by Sirius_Alpha on 5th June 2009, 2:41 pm

Not exactly understanding the image that was provided of VB 10's astrometric motion, I looked around and found a .avi video on the Planetary Photojournal. I converted the .avi to .gif.


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Re: Discovery of a planet by astrometry

Post by Lazarus on 5th June 2009, 3:55 pm

For those who like coincidences, it turns out there's a pretty good match between the following mass ratios

mVB 10 / mSun = 0.0779
mVB 10b / mVB 10 = 0.0784

See also Greg Laughlin's take on the discovery, where he characterises it as "a low-mass brown dwarf impinging into the 'planet desert' from above".
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