New 24 Ám light curve for υ And b

View previous topic View next topic Go down

A new 24 micron phase curve for upsilon And b

Post by Borislav on 20th July 2010, 2:58 pm


Borislav
Jovian
Jovian

Number of posts : 561
Registration date : 2008-11-12

View user profile

Back to top Go down

New 24 Ám light curve for υ And b

Post by Sirius_Alpha on 3rd August 2010, 8:11 pm

A New 24 micron Phase Curve for upsilon Andromedae b
http://arxiv.org/abs/1008.0393

Abstract wrote:We report the detection of 24 micron variations from the planet-hosting upsilon Andromedae system consistent with the orbital periodicity of the system's innermost planet, upsilon And b. We find a peak-to-valley phase curve amplitude of 0.00130 times the mean system flux. Using a simple model with two hemispheres of constant surface brightness and assuming a planetary radius of 1.3 Jupiter radii gives a planetary temperature contrast of >900 K and an orbital inclination of >28 degrees. We further report the largest phase offset yet observed for an extrasolar planet: the flux maximum occurs ~80 degrees before phase 0.5. Such a large phase offset is difficult to reconcile with most current atmospheric circulation models. We improve on earlier observations of this system in several important ways: (1) observations of a flux calibrator star demonstrate the MIPS detector is stable to 10^-4 on long timescales, (2) we note that the background light varies systematically due to spacecraft operations, precluding use of this background as a flux calibrator (stellar flux measured above the background is not similarly affected), and (3) we calibrate for flux variability correlated with motion of the star on the MIPS detector. A reanalysis of our earlier observations of this system is consistent with our new result.

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

Number of posts : 3494
Location : Earth
Registration date : 2008-04-06

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

Back to top Go down

Re: New 24 Ám light curve for υ And b

Post by Borislav on 4th August 2010, 4:19 am


Borislav
Jovian
Jovian

Number of posts : 561
Registration date : 2008-11-12

View user profile

Back to top Go down

Re: New 24 Ám light curve for υ And b

Post by Sirius_Alpha on 4th August 2010, 2:01 pm

Yes, thanks for pointing that out. I thought there was already a thread but didn't see it.

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

Number of posts : 3494
Location : Earth
Registration date : 2008-04-06

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

Back to top Go down

Displaced hotspot on upsilon Andromedae b

Post by Lazarus on 19th October 2010, 3:43 pm

Yet another surprise from hot Jupiter atmospheres. Hotspot seems to be 80 degrees away from the substellar point.

Hot Jupiters are weird.
avatar
Lazarus
dG star
dG star

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

View user profile

Back to top Go down

Re: New 24 Ám light curve for υ And b

Post by Sirius_Alpha on 19th October 2010, 5:20 pm

The preprint for this can be found here.

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

Number of posts : 3494
Location : Earth
Registration date : 2008-04-06

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

Back to top Go down

Re: New 24 Ám light curve for υ And b

Post by Lazarus on 19th October 2010, 5:22 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: New 24 Ám light curve for υ And b

Post by Sirius_Alpha on 19th October 2010, 6:18 pm

Done. Smile

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

Number of posts : 3494
Location : Earth
Registration date : 2008-04-06

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

Back to top Go down

Re: New 24 Ám light curve for υ And b

Post by Borislav on 20th October 2010, 4:21 am

http://arxiv.org/abs/1008.0393


Probably it says is the constant weather phenomenon, and that the planets really tidally captured (otherwise, the phase curves would have been different).

Borislav
Jovian
Jovian

Number of posts : 561
Registration date : 2008-11-12

View user profile

Back to top Go down

Re: New 24 Ám light curve for υ And 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