OGLE2-TR-L9 b

View previous topic View next topic Go down

OGLE2-TR-L9 b

Post by Sirius_Alpha on 3rd December 2008, 9:32 pm

OGLE2-TR-L9: An extrasolar planet transiting a fast-rotating F3 star

http://arxiv.org/abs/0812.0599



Abstract wrote:Context: Photometric observations for the OGLE-II microlens monitoring campaign have been taken in the period 1997-2000. All light curves of this campaign have recently been made public. Our analysis of these data has revealed 13 low-amplitude transiting objects among ~15700 stars in three Carina fields towards the galactic disk. One of these objects, OGLE2-TR-L9 (P~2.5 days), turned out to be an excellent transiting planet candidate.
Aims: In this paper we report on our investigation of the true nature of OGLE2-TR-L9, by re-observing the photometric transit with the aim to determine the transit parameters at high precision, and by spectroscopic observations, to estimate the properties of the host star, and to determine the mass of the transiting object through radial velocity measurements.
Methods: High precision photometric observations have been obtained in g', r', i', and z' band simultaneously, using the new GROND detector, mounted on the MPI/ESO 2.2m telescope at La Silla. Eight epochs of high-dispersion spectroscopic observations were obtained using the fiber-fed FLAMES/UVES Echelle spectrograph, mounted on ESO's Very Large Telescope at Paranal.
Results: The photometric transit, now more than 7 years after the last OGLE-II observations, was re-discovered only ~8 minutes from its predicted time. The primary object is a fast rotating F3 star, with vsini=39.33+-0.38 km/s, T=6933+-58 K, log g = 4.25+-0.01, and [Fe/H] = -0.05+-0.20. The transiting object is an extrasolar planet with M_p=4.5+-1.5 M_Jup and R_p=1.61+-0.04 R_Jup. The rejection of possible blend scenarios was based on a quantitative analysis of the multi-color photometric data [abridged].


Last edited by Sirius_Alpha on 5th July 2010, 8:32 pm; edited 1 time in total

_________________
Caps Lock: Cruise control for 'Cool'!
avatar
Sirius_Alpha
Admin
Admin

Number of posts : 3495
Location : Earth
Registration date : 2008-04-06

View user profile http://solar-flux.forumandco.com/

Back to top Go down

Re: OGLE2-TR-L9 b

Post by Edasich on 4th December 2008, 8:44 am

Finally confirmed. The Hot Jupiter has quite a "bloated" radius, close to that of TrES-4b. And it's nearly as massive as Tau Bootis b.
avatar
Edasich
dM star
dM star

Number of posts : 1518
Location : Tau Ceti g - Mid Latitudes
Registration date : 2008-06-02

View user profile

Back to top Go down

Re: OGLE2-TR-L9 b

Post by Lazarus on 4th December 2008, 2:54 pm

avatar
Lazarus
dG star
dG star

Number of posts : 2845
Registration date : 2008-06-12

View user profile

Back to top Go down

Re: OGLE2-TR-L9 b

Post by Sirius_Alpha on 4th December 2008, 8:38 pm

Very interesting! Found by undergrad students during a search algorithm project. Very inspiring!

The claims that OGLE2-TR-L9 is the hottest star to host a planetary companion, however, are simply untrue, due to the discovery of three solar systems with A-type stars. Still, this star is rather hot for a RV detection of a planet.

_________________
Caps Lock: Cruise control for 'Cool'!
avatar
Sirius_Alpha
Admin
Admin

Number of posts : 3495
Location : Earth
Registration date : 2008-04-06

View user profile http://solar-flux.forumandco.com/

Back to top Go down

Re: OGLE2-TR-L9 b

Post by Lazarus on 4th December 2008, 8:44 pm

.


Last edited by Lazarus on 5th December 2008, 9:48 am; edited 1 time in total
avatar
Lazarus
dG star
dG star

Number of posts : 2845
Registration date : 2008-06-12

View user profile

Back to top Go down

Re: OGLE2-TR-L9 b

Post by Sirius_Alpha on 4th December 2008, 9:22 pm

The discovery paper also makes the claim of the hottest exoplanet host star. It may be that the paper was written before the announcement of Fomalhaut b and friends. Perhaps also the writer of the article just took information from this paper. Perhaps the writer of the article didn't know Fomalhaut was a hotter star, so just went along with it.

I find it curious that the writers of the paper did not edit their paper accordingly after Fomalhaut b, HR 8799 b, c, d, and Bet Pic b were all announced.

_________________
Caps Lock: Cruise control for 'Cool'!
avatar
Sirius_Alpha
Admin
Admin

Number of posts : 3495
Location : Earth
Registration date : 2008-04-06

View user profile http://solar-flux.forumandco.com/

Back to top Go down

Updated OGLE2-TR-L9 parameters. Evidence for TTVs?

Post by Sirius_Alpha on 5th July 2010, 8:29 pm

New Parameters and Transit Timing Studies for OGLE2-TR-L9 b
http://arxiv.org/abs/1007.0589

Abstract wrote:Context: Repeated observations of exoplanet transits allow us to refine the planetary parameters and probe them for any time dependent variations. In particular deviations of the period from a strictly linear ephemeris, transit timing variations (TTVs), can indicate the presence of additional bodies in the planetary system.
Aims: Our goal was to reexamine the largely unstudied OGLE2-TR-L9 system with high cadence, multi-color photometry in order to refine the planetary parameters and probe the system for TTVs.
Methods: We observed five full transits of OGLE2-TR-L9 with the GROND instrument at the ESO/MPG 2.2 m telescope at La Silla Observatory. GROND is a multichannel imager that allowed us to gather simultaneous light curves in the g', r', i', and z' filters.
Results: From our analysis we find that the semi-major axis and the inclination differ from the previously published values. With the newly observed transits, we were able to refine the ephemeris to 2454492.80008(+/- 0.00014) + 2.48553417(+/- 6.4) x 10^-7 E. The newly derived parameters are a=0.0418 (+/- 0.0015) AU, r_p =1.67 (+/- 0.05) R_j, and inc=82.47{\deg} (+/- 0.12), differing significantly in a and inc from the previously published values. Within our data, we find indications for TTVs.

_________________
Caps Lock: Cruise control for 'Cool'!
avatar
Sirius_Alpha
Admin
Admin

Number of posts : 3495
Location : Earth
Registration date : 2008-04-06

View user profile http://solar-flux.forumandco.com/

Back to top Go down

Re: OGLE2-TR-L9 b

Post by youknowandy on 10th July 2010, 8:22 am

wow, the planet got bigger by 0.05 of a Jupiter radius.
avatar
youknowandy
Meteor
Meteor

Number of posts : 27
Registration date : 2008-06-16

View user profile

Back to top Go down

Re: OGLE2-TR-L9 b

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