Extrasolar Planets

[RigelKentaurusA]

HAT-P-31b,c: A Transiting, Eccentric, Hot Jupiter and a Long-Period, Massive Third-Body
http://arxiv.org/abs/1106.1169

HAT-P-32b and HAT-P-33b: Two Highly Inflated Hot Jupiters Transiting High-Jitter Stars
http://arxiv.org/abs/1106.1212

Possible detection of two giant extrasolar planets orbiting the eclipsing polar UZ Fornacis
http://arxiv.org/abs/1106.1404

 

[RigelKentaurusA]

Discovery and Mass Measurements of a Cold, 10-Earth Mass Planet and Its Host Star
http://arxiv.org/abs/1106.2160

 

[RigelKentaurusA]

Multiple "new" planets from CoRoT. Some of them were public before today, but they're all being announced in a nice batch of ten.

CoRoT-16 b - a hot Jupiter.
CoRoT-17 b - a hot Jupiter.
CoRoT-18 b - a hot Jupiter.
CoRoT-19 b - a hot Jupiter.
CoRoT-20 b - a very young (~0.1 Gyr) hot Jupiter system.
CoRoT-21 b - a hot Jupiter.
CoRoT-22 b - sub-Saturn planet, highly inflated, unconfirmed, pending a mass measurement.
CoRoT-23 b - a hot Jupiter.
CoRoT-24 b,c - two ~Neptunes, both unconfirmed, pending mass measurements? (I dunno how they got the mass for the outermost planet, the paper is not yet public).

 

[RigelKentaurusA]

One of the Kepler planet candidates has been confirmed as a planet.
SOPHIE velocimetry of Kepler transit candidates III. KOI-423b: a 18 Mjup transiting companion around a F7IV star

Another candidate is determined to be a low-mass star. Another candidate wasn't detected in radial velocity, ruling out a mass > 3.4 M_jupiter

 

[RigelKentaurusA]

Five planets, two of which are in one system:
The HARPS search for southern extra-solar planets. XXX. Planetary systems around stars with solar-like magnetic cycles and short-term activity variation
http://arxiv.org/list/astro-ph.EP/new

Transiting exoplanets from the CoRoT space mission. XX. CoRoT-18b: a massive hot jupiter on a prograde, nearly aligned orbit
http://arxiv.org/abs/1107.2032

I've not been able to attend to this thread much recently due to difficulties getting the intertubes established at my new residence. This problem has been resolved.

 

[CommonEnlightenment]

I realize that this 'discovery' is not as new as most that are posted in this thread. It's a finding that originally peaked my interest some years ago.


http://www.nasa.gov/mission_pages/hubble/science/hst_img_20080319.html

 

[RigelKentaurusA]

Visible light detection of the eclipse of TrES-2 b behind its star.
This gives us a measure of how much visible light it reflects back, which turns out to be very low, about 2%, but some of that optical brightness is thermal in origin. So the planet itself is very dark.

Detection of visible light from the darkest world

 

[nasher168]

Do they understand the reason for it being so dark yet? It might have been mentioned in the abstract linked, but if I'm honest, most of it is only vaguely comprehensible to me :?

 

[CommonEnlightenment]

Not saying that ice or snow or water are present (probably far too hot) but I think you catch the drift.......

 

[RigelKentaurusA]

They have some ideas, but nothing definitive. Some dark absorber in the atmosphere, perhaps Titanium Oxide or Vanadium, could be the cause.
Theory suggests hot Jupiters are typically dark. Of the four hot Jupiters for which we have albedo measurements, three conform to this idea (CoRoT-1 b, HAT-P-7 b, and now TrES-2 b), while one does not (Kepler-7 b).

 

[CommonEnlightenment]

Not an Extrasolar planet but still interesting (Well, I would imagine that many Extrasolar planets exist if we use our Galaxy as a model).

http://www.astronomy.com/en/News-Observing/News/2011/08/A%20cosmic%20exclamation%20point.aspx

 

[RigelKentaurusA]

A bunch of low mass planets have been announced.

Planetary system at HD 20794. Three planets, with orbital periods of 18.315, 40.114, 90.309 days, circular orbits, and masses of 2.7, 2.4, and 4.8 Earth-masses.

Planetary system at HD 192310. It has a previously announced Neptune-mass planet with a mass of 16.9 Earths, at a period of 74.72 days. This new announcement adds another Neptune with a mass of 24 Earths at a period of 525.8 days.

A planetary companion to HD 85512 in the inner edge of the habitable zone. It has a mass of 3.6 Earths at a period of 58.43 days. This planet is now probably our best shot at a habitable exoplanet.

The HARPS search for Earth-like planets in the habitable zone: I -- Very low-mass planets around HD20794, HD85512 and HD192310
http://arxiv.org/abs/1108.3447

A Habitable Planet around HD 85512?
http://arxiv.org/abs/1108.3561

 

[televator]

Looking good. They're getting better at detecting lower mass planets. Not that finding exact earth dimensions would really matter for a planet that could possibly harbor life, right?

 

[RigelKentaurusA]

TrES-5: A Massive Jupiter-sized Planet Transiting A Cool G-dwarf
http://arxiv.org/abs/1108.3572

 

[RigelKentaurusA]

Retired A Stars and Their Companions: Eighteen New Jovian Planets
http://arxiv.org/abs/1108.4205

 

[RigelKentaurusA]

A remarkable new planetary system from Kepler, KOI-730 (pending Kepler-# designation).

Four sub-Jovian planets in a chain of resonances about their host star. Much as how Jupiter's three inner Galilean moons have a 1:2:4 resonance (for every orbit of Ganymede, Callisto conducts two, Io conducts four), the four planets at KOI-730 are also in resonance. The resonant configuration here is 3:4:6:8 (for every three orbits of the outermost planet, the adjacent planet further in conducts four, the next planet in completes six, and the innermost completes eight).

This is the most complex resonant configuration known of any astronomical body, and has implications for our understanding of planetary migration.

The masses of these four planets are not determined, but there are two strong arguments for a planetary nature:

1) The orbital period of a planet candidate discovered through transit photometry is easy to measure. If you have both the orbital period and the transit duration, you have a value for the orbital velocity and can determine the stellar mass. The stellar radius can be reasonably well inferred. This allows you to estimate the stellar density. For multiple planets transiting the same star, they will all give values of for the stellar density that are in agreement with each other. If there were an eclipsing binary (or two, or three, or four) in the background to produce these transit-like signatures, then each periodicity will yield different values for the stellar mass.

2) Resonances. What's the likelihood that background eclipsing binaries are going to have orbital period ratios in a nice 3:4:6:8 pattern, better than one part in a thousand? Inconceivable.

So the most reasonable situation is that four, sub-Jovian sized objects are orbiting a single star. Their masses must be in the planetary regime to avoid dynamic instability for the system, protecting it from the mutual perturbations of each object and leading to scattering. A planetary nature for all four candidates is thus overwhelmingly the most likely scenario.

 

[RigelKentaurusA]

Additional Kepler results.

For the first time, a non-transiting planet has been discovered through transit timing variations, at Kepler-19.

Press release.
EPE Stats.
Discovery Paper.

"The Kepler-19 System: A Transiting 2.2 R_⊕ Planet and a Second Planet Detected via Transit Timing Variations"

 

[RigelKentaurusA]

Discovery and Atmospheric Characterization of Giant Planet Kepler-12b: An Inflated Radius Outlier
http://arxiv.org/abs/1109.1611

 

[nasher168]

Out of interest, is that a Celestia screenshot in your KOI-730 post?
If so, how did it get updated so soon after a discovery?

 

[RigelKentaurusA]

Out of interest, is that a Celestia screenshot in your KOI-730 post?

Yes.

If so, how did it get updated so soon after a discovery?

Manually. You can open any .ssc and .stc file and see that definitions for stars and planets are pretty straightforward. It doesn't take much effort to write one up and craft planets and stars all over the Universe.