No transits detected for HD 168443 b, confirmation of c

View previous topic View next topic Go down

No transits detected for HD 168443 b, confirmation of c

Post by Sirius_Alpha on 25th September 2011, 8:17 pm

A Search for the Transit of HD 168443b: Improved Orbital Parameters and Photometry
http://arxiv.org/abs/1109.5166

The discovery of transiting planets around bright stars holds the potential to greatly enhance our understanding of planetary atmospheres. In this work we present the search for transits of HD 168443b, a massive planet orbiting the bright star HD 168443 V=6.92 with a period of 58.11 days. The high eccentricity of the planetary orbit e=0.53 significantly enhances the a-priori transit probability beyond that expected for a circular orbit, making HD 168443 a candidate for our ongoing Transit Ephemeris Refinement and Monitoring Survey (TERMS). Using additional radial velocities from Keck-HIRES, we refined the orbital parameters of this multi-planet system and derived a new transit ephemeris for HD 168443b. The reduced uncertainties in the transit window make a photometric transit search practicable. Photometric observations acquired during predicted transit windows were obtained on three nights. CTIO 1.0 m photometry acquired on 2010 September 7 had the required precision to detect a transit but fell just outside of our final transit window. Nightly photometry from the T8 0.8 m Automated Photometric Telescope (APT) at Fairborn Observatory, acquired over a span of 109 nights, demonstrates that HD 168443 is constant on a time scale of weeks. Higher-cadence photometry on 2011 April 28 and June 25 shows no evidence of a transit. We are able to rule out a non-grazing transit of HD 168443b.

Having been discovered in 1998, was this planet not checked for transits before now? We weren't exactly suffering an over-abundance of planet candidates to check for transits in 1998.

_________________
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: No transits detected for HD 168443 b, confirmation of c

Post by tommi59 on 26th September 2011, 3:15 am

This is weird they was not interested in seeking transits especially when discovery of planets were not often.Where is confirmation planet c?
avatar
tommi59
Jovian
Jovian

Number of posts : 548
Age : 39
Location : Baile Atha Cliath
Registration date : 2010-07-31

View user profile

Back to top Go down

Re: No transits detected for HD 168443 b, confirmation of c

Post by Sirius_Alpha on 26th September 2011, 7:20 am

They present a two-planet fit for the system. Last I heard the outer planet was unconfirmed.

_________________
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: No transits detected for HD 168443 b, confirmation of c

Post by tommi59 on 26th September 2011, 7:43 am

At least 17 mass of jupiter planet c was previously reported as brown dwarf before the limit for bd was increased in my opinion not rightfully.The planet b is so eccentric that inclination probably is high so there is no possibility for transit is rather far from host star
avatar
tommi59
Jovian
Jovian

Number of posts : 548
Age : 39
Location : Baile Atha Cliath
Registration date : 2010-07-31

View user profile

Back to top Go down

Re: No transits detected for HD 168443 b, confirmation of c

Post by Lazarus on 26th September 2011, 1:14 pm

EPE demoted it to unconfirmed after astrometric results suggested the true mass was around 35 Jupiter masses or so, well into the brown dwarf regime (note EPE used to use a 20 Jupiter masses limit anyway).

Contrary to tommi59's assertion, the eccentricity does has no implications whatsoever the inclination relative to the plane of the sky (this is the inclination that is relevant for transit probabilities). Whether it suggests there might be high mutual inclination between the orbits of the planets is another matter.
avatar
Lazarus
dG star
dG star

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

View user profile

Back to top Go down

Re: No transits detected for HD 168443 b, confirmation of c

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