Retired A Stars and Their Companions IV. Seven Jovian Exoplanets from Keck Observatory

View previous topic View next topic Go down

Retired A Stars and Their Companions IV. Seven Jovian Exoplanets from Keck Observatory

Post by Mongo on 18th March 2010, 9:45 pm

http://xxx.lanl.gov/abs/1003.3445  We report precise Doppler measurements of seven subgiants from Keck Observatory. All seven stars show variability in their radial velocities consistent with planet-mass companions in Keplerian orbits. The host stars have masses ranging from 1.1 < Mstar/Msun < 1.9, radii 3.4 < Rstar/Rsun < 6.1, and metallicities -0.21 < [Fe/H] < +0.26. The planets are all more massive than Jupiter (Msini > 1 Mjup) and have semimajor axes > 1 AU. We present millimagnitude photometry from the T3 0.4m APT at Fairborn observatory for five of the targets. Our monitoring shows these stars to be photometrically stable, further strengthening the interpretation of the observed radial velocity variability. The orbital characteristics of the planets thus far discovered around former A-type stars are very different from the properties of planets around dwarf stars of spectral type F, G and K, and suggests that the formation and migration of planets is a sensitive function of stellar mass. Three of the planetary systems show evidence of long-term, linear trends indicative of additional distant companions. These trends, together with the high planet masses and increased occurrence rate, indicate that A-type stars are very promising targets for direct imaging surveys.
avatar
Mongo
Asteroid
Asteroid

Number of posts : 57
Age : 54
Location : Greater Toronto, Canada
Registration date : 2009-05-18

View user profile

Back to top Go down

Re: Retired A Stars and Their Companions IV. Seven Jovian Exoplanets from Keck Observatory

Post by Borislav on 19th March 2010, 7:05 am

http://solar-flux.forumandco.com/extrasolar-news-and-discoveries-f2/the-california-planet-survey-i-four-new-giant-exoplanets-t562-15.htm#3532
Uncertainty closed

In general, at 500 subgiants Keck telescope is rewritten, at least 100-150 new planetary systems.

Borislav
Jovian
Jovian

Number of posts : 556
Registration date : 2008-11-12

View user profile

Back to top Go down

Re: Retired A Stars and Their Companions IV. Seven Jovian Exoplanets from Keck Observatory

Post by Sponsored content


Sponsored content


Back to top Go down

View previous topic View next topic Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum