Two more planet candidates detected by the Planet Hunters announced at the AAS 219.
Great news. That 284-day candidate is truly exciting, should it be confirmed.
Well, this one is interesting!
Possible Disintegrating Short-Period Super-Mercury Orbiting KIC 12557548
We report here on the discovery of stellar occultations, observed with Kepler, that recur periodically at 15.685 hour intervals, but which vary in depth from a maximum of 1.2% to a minimum that can be less than 0.2%. The star that is apparently being occulted is KIC 12557548, a V = 16 magnitude K dwarf with T_eff = 4400 K. The out-of-occultation behavior shows no evidence for ellipsoidal light variations, indicating that the mass of the orbiting object is less than ~3 M_J. Because the eclipse depths are highly variable, they cannot be due solely to transits of a single planet with a fixed size. We discuss but dismiss a scenario involving a binary giant planet whose mutual orbit plane precesses, bringing one of the planets into and out of a grazing transit. This scenario seems ruled out by the dynamical instability that would result from such a configuration. The much more likely explanation involves macroscopic particles - e.g., dust, possibly in the form of micron-sized pyroxene grains - escaping the atmosphere of a slowly disintegrating planet not much larger than Mercury in size. The planetary surface is hot enough to sublimate; the resultant silicate vapor accelerates off the planet via a Parker-type thermal wind, dragging dust grains with it. We infer a mass loss rate from the observations of order ~1 M_earth/Gyr, with a dust-to-gas ratio possibly of order unity. For our fiducial 0.1 M_earth planet (twice the mass of Mercury), the evaporation timescale may be ~0.2 Gyr. Smaller mass planets are disfavored because they evaporate still more quickly, as are larger mass planets because they have surface gravities too strong to sustain outflows with the requisite mass-loss rates. The occultation profile evinces an ingress-egress asymmetry that could reflect a comet-like dust tail trailing the planet; we present simulations of such a tail.
The KIC lists magnitudes of g=16.7, r=15.6, i=15.3,
and z= 15.1 for star 12557548. From this we estimate
the V magnitude is 16.2 (Windhorst et al. 1991). If we
take the absolugte visual magnitude of the K star to be
+7.6 (with Ls ' 0:14L), and correct for an estimated
AV ' 0:22, this puts the object at a distance of about
This proliferation of tiny planets is becoming quite confusing... And none of them confirmed with radial velocity measurements.
A Jovian planet detected orbiting the white dwarf/red dwarf binary RR Cae using transit timings. Another planet with long orbit (p>26.3 years) suspected.
Seems that planets are common in such systems.
A Circumbinary Planet in Orbit Around the Short-Period White-Dwarf Eclipsing Binary RR Cae
The central binary has a period of only 7.3h. The (probable) planet has mass >= 4.2+/-0.4 MJ and period 11.9 years. If the system is co-planar the true mass should be close to the lower limit because the binary is eclipsing.
arxiv.org/abs/1201.5075We report the discovery of HAT-P-38b, a Saturn-mass exoplanet transiting the V=12.56 dwarf star GSC 2314-00559 on a P = 4.6404 d circular orbit. The host star is a 0.89Msun late G-dwarf, with solar metallicity, and a radius of 0.92Rsun. The planetary companion has a mass of 0.27MJ, and radius of 0.82RJ. HAT-P-38b is one of the closest planets in mass and radius to Saturn ever discovered.
Generally, I like this thread but I don't always find the "interesting" aspect of the listed discoveries self-evident. Sometimes, I could use a little tip.
Here is an explanation of the "Box Least-Squares method" that was used.
The new phenomenon of "exoplanet ennui"
LOL. Much as I love exoplanets, I'm sure the day will come (maybe even within my own lifetime) when exoplanets become the new "vermin of the skies".
Imagine: "Another Earthlike planet? If you're not seeing the red edge and free oxygen, Myers, round file it with the rest..."
That makes 39 planets discovered this year!
According to the Extrasolar Planets Encyclopaedia, a total of 188 planets were discovered in 2011 (histogram view). For the year 2010 the number is 114, so the jump is huge. The discovery rate looks exponential! Of course, the values are not constant so some candidates may be removed (or new ones added).
If it's another "hot Jupiter" that's been discovered, what makes it different from the other "hot Jupiters" that we already know about? What makes the particular world in a given link distinctive? Just saying that it's there doesn't necessarily make it interesting. Even a quick sentence saying, "Based on its mass, we believe this world is made entirely of marshmallow fluff" or "Based on its mass and orbital period, we believe this world may get swallowed by its star in less than 1000 years" would be very helpful and enlightening to us lay folk.
I'm just asking for the same sort of treatment for extrasolar planet discoveries as BAUT suggests for linking to other content: instead of just providing the link, also provide a brief description of what's being linked to and why we might think it's interesting.
I consider a typical extrasolar planet discovery "uninteresting" when we start finding Earth-like planets in thousands.
700+ planets, even though impressive, are not that much after all.