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TOPIC: Extrasolar Planets
Blobrana


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HD167042b
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Title: Retired A Stars and Their Companions II: Jovian planets orbiting kappa Coronae Borealis and HD167042
Authors: John A. Johnson, Geoffrey W. Marcy, Debra A. Fischer, Jason T. Wright, Sabine Reffert, Julia M. Kregenow, Peter K. G. Williams, Kathryn M. G. Peek

We report precise Doppler measurements of two evolved stars, kappa CrB (HD142091) and HD 167042, obtained at Lick Observatory as part of our search for planets orbiting intermediate-mass subgiants. Periodic variations in the radial velocities of both stars reveal the presence of substellar orbital companions. These two stars are notably massive with stellar masses of 1.80 Msun and 1.64 Msun, indicating that they are former A-type dwarfs that have evolved off of the main sequence and are now K-type subgiants. The planet orbiting kappa CrB has a minimum mass Msini = 1.8 Mjup, eccentricity e = 0.146 and a 1208 day period, corresponding to a semimajor axis of 2.7 AU. The planet around HD167042 has a minimum mass Msini = 1.7 Mjup and a 412.6 day orbit, corresponding to a semimajor axis of 1.3 AU. The eccentricity of HD167042b is consistent with circular (e = 0.027±0.04), adding to the rare class of known exoplanets in long-period, circular orbits similar to the Solar System gas giants. Like all of the planets previously discovered around evolved A stars, kappa CrBb and HD167042b orbit beyond 0.8 AU.

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Blobrana


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Posts: 131433
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OGLE-TR-211
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Title: OGLE-TR-211 - a new transiting inflated hot Jupiter from the OGLE survey and ESO LP666 spectroscopic follow-up program
Authors: A. Udalski, F. Pont, D. Naef, C. Melo, F. Bouchy, N.C. Santos, C. Moutou, R.F. Diaz, W. Gieren, M. Gillon, S. Hoyer, M. Mayor, T. Mazeh, D. Minniti, G. Pietrzynski, D. Queloz, S. Ramirez, M.T. Ruiz, O. Tamuz, S. Udry, M. Zoccali, M. Kubiak, M.K. Szymanski, I. Soszynski, O. Szewczyk, K. Ulaczyk, L. Wyrzykowski

We present results of the photometric campaign for planetary and low-luminosity object transits conducted by the OGLE survey in 2005 season (Campaign #5). About twenty most promising candidates discovered in these data were subsequently verified spectroscopically with the VLT/FLAMES spectrograph.
One of the candidates, OGLE-TR-211, reveals clear changes of radial velocity with small amplitude of 82 m/sec, varying in phase with photometric transit ephemeris. Thus, we confirm the planetary nature of the OGLE-TR-211 system. Follow-up precise photometry of OGLE-TR-211 with VLT/FORS together with radial velocity spectroscopy supplemented with high resolution, high S/N VLT/UVES spectra allowed us to derive parameters of the planet and host star. OGLE-TR-211b is a hot Jupiter orbiting a F7-8 spectral type dwarf star with the period of 3.68 days. The mass of the planet is equal to 1.03+/-0.20 M_Jup while its radius 1.36+0.18-0.09 R_Jup. The radius is about 20% larger than the typical radius of hot Jupiters of similar mass. OGLE-TR-211b is, then, another example of inflated hot Jupiters - a small group of seven exoplanets with large radii and unusually small densities - objects being a challenge to the current models of exoplanets.

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Blobrana


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RE: Extrasolar Planets
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Title: HD196885, a close binary star with a 3.7-year planet
Authors: A.C.M. Correia, S. Udry, M. Mayor, A. Eggenberger, D. Naef, J.-L. Beuzit, C. Perrier, D. Queloz, J.-P. Sivan, F. Pepe, N.C. Santos, D. Segransan

We report the presence of a planet orbiting HD196885_A, with an orbital period of 1349 days. This star was previously suggested to host a 386-day planet, but we cannot confirm its existence. We also detect the presence of a stellar companion, HD196885_B, and give some constraints on its orbit.

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Blobrana


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Title: Microlensing Searches for Planets: Results and Future Prospects
Authors: B. Scott Gaudi (Ohio State University)

Microlensing is potentially sensitive to multiple-planet systems containing analogs of all the solar system planets except Mercury, as well as to free floating planets. I review the landscape of microlensing planet searches, beginning with an outline of the method itself, and continuing with an overview of the results that have been obtained to date. Four planets have been detected with microlensing. I discuss what these detections have taught us about the frequency of terrestrial and giant planets with separations beyond the ``snow line.'' I then discuss the near and long-term prospects for microlensing planet searches, and in particular speculate on the expected returns of next-generation microlensing experiments both from the ground and from space. When combined with the results from other complementary surveys, next generation microlensing surveys can yield an accurate and complete census of the frequency and properties of essentially all planets with masses greater than that of Mars.

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Blobrana


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Extra solar planets, which are known as `Super-Earths`, might harbour life for a longer period than our own, reveals a new research by scientists.
Similar to Earth, these planets can stay warm enough for life up to 35 per cent longer than the Earth.
The time period for the longevity of such planets is up to 11.9 billion, beating the estimated 8.8 billion years for Earth.
The reason for `Super-Earths` staying hot for longer than planets like ours are based on a number of factors that make a planet habitable. They mainly include volcanism and the atmosphere and the size of the star tat the planet orbits.

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Blobrana


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Journey to a Star Rich With Planets



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Blobrana


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A new world has been discovered nestled in the largest planetary system ever seen outside our solar system, fuelling speculation there are many other habitable Earth-like planets in the Milky Way galaxy.
Astronomers doubt the new-found planet - one of five circling a nearby star, which is visible with binoculars - can support life.
But they told a teleconference Tuesday the discovery fuels their conviction that many Earth-like planets are just waiting to be discovered.

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Blobrana


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Title: Extreme Habitability: Formation of Habitable Planets in Systems with Close-in Giant Planets and/or Stellar Companions
Authors: Nader Haghighipour

With more than 260 extrasolar planetary systems discovered to-date, the search for habitable planets has found new grounds. Unlike our solar system, the stars of many of these planets are hosts to eccentric or close-in giant bodies. Several of these stars are also members of moderately close (<40 AU) binary or multi-star systems. The formation of terrestrial objects in these "extreme" environments is strongly affected by the dynamics of their giant planets and/or their stellar companions. These objects have profound effects on the chemical structure of the disk of planetesimals and the radial mixing of these bodies in the terrestrial regions of their host stars. For many years, it was believed that such effects would be so destructive that binary stars and also systems with close-in giant planets would not be able to form and harbour habitable bodies. Recent simulations have, however, proven otherwise. I will review the results of the simulations of the formation and long-term stability of Earth-like objects in the habitable zones of such "extreme" planetary systems, and discuss the possibility of the formation of terrestrial planets, with significant amounts of water, in systems with hot Jupiters, and also around the primaries of moderately eccentric close binary stars.

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Blobrana


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55 Cancri.kmz
Google Sky file


55 Cancri (1 Cnc)

Location
RA: 8h52m35.8s
DEC: +28°19m51.0s

-- Edited by Blobrana at 16:14, 2008-01-12

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Blobrana


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Date:
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55 Cancri



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