Exoplanets, 2003–2013

© 2014 by the American Academy of Arts & Sciences.Cosmologists and philosophers had long suspected that our sun was a star, and that just like the sun, other stars were also orbited by planets. These and similar ideas led to Giordano Bruno being burned at the stake by the Roman Inquisition in 1600. It was not until 1989, however, that the first exoplanet–a planet outside the solar system–was discovered. While the rate of subsequent discoveries was slow, most of these were important milestones in the research on extrasolar planets, such as finding planets around a pulsar (a compact remnant of a collapsed star) and finding Jupiter-mass planets circling their stars on extremely short period orbits (in less than a few Earth-days). But the first decade of our millennium witnessed an explosion in the number of discovered exoplanets. To date, there are close to one thousand confirmed and three thousand candidate exoplanets. We now know that a large fraction of stars have planets, and that these planets show an enormous diversity, with masses ranging from that of the moon (1/100 that of Earth, or 0.01M⊕) to twenty-five times that of Jupiter (25MJ, or approximately 10,000M⊕); orbital periods from less than a day to many years; orbits from circular to wildly eccentric (ellipses with an “eccentricity” parameter of 0.97, corresponding to an aspect ratio of 1:4); and mean densities from 0.1g cm−3(1/10 of water) to well over 25g cm−3. Some of these planets orbit their stars in the same direction as the star spins, some orbit in the opposite direction or pass over the stellar poles. Observations have been immensely useful in constraining theories of planetary astrophysics, including with regard to the formation and evolution of planets. In this essay, I summarize some of the key results

ZASPE: A Code to Measure Stellar Atmospheric Parameters and their Covariance from Spectra

We describe the Zonal Atmospheric Stellar Parameters Estimator (ZASPE), a new algorithm, and its associated code, for determining precise stellar atmospheric parameters and their uncertainties from high-resolution echelle spectra of FGK-type stars. ZASPE estimates stellar atmospheric parameters by comparing the observed spectrum against a grid of synthetic spectra only in the most sensitive spectral zones to changes in the atmospheric parameters. Realistic uncertainties in the parameters are computed from the data itself, by taking into account the systematic mismatches between the observed spectrum and the best-fitting synthetic one. The covariances between the parameters are also estimated in the process. ZASPE can in principle use any pre-calculated grid of synthetic spectra, but unbiased grids are required to obtain accurate parameters. We tested the performance of two existing libraries, and we concluded that neither is suitable for computing precise atmospheric parameters. We describe a process to synthesize a new library of synthetic spectra that was found to generate consistent results when compared with parameters obtained with different methods (interferometry, asteroseismology, equivalent widths)

First Results of the Konkoly Blazhko Survey II

The two parts of the Konkoly Blazhko Survey (KBS I and II) are introduced. The most important preliminary findings of the second part are presented in comparison to the results of the first part. Two interesting cases of very strong modulation from the KBS II are also shown

HAT-P-20b-HAT-P-23b: Four Massive Transiting Extrasolar Planets

We report the discovery of four relatively massive (2–7 M J ) transiting extrasolar planets. HAT-P-20b orbits the moderately bright V = 11.339 K3 dwarf star GSC 1910-00239 on a circular orbit, with a period P = 2 . 875317 ± 0 . 000004 days, transit epoch T c = 2455080 . 92661 ± 0 . 00021 (BJD UTC ), and transit dura- tion 0 . 0770 ± 0 . 0008 days. The host star has a mass of 0 . 76 ± 0 . 03 M , radius of 0 . 69 ± 0 . 02 R , effective temperature 4595 ± 80 K, and metallicity [Fe / H] = +0 . 35 ± 0 . 08. The planetary companion has a mass of 7 . 246 ± 0 . 187 M J and a radius of 0 . 867 ± 0 . 033 R J yielding a mean density of 13 . 78 ± 1 . 50 g cm − 3 . HAT-P-21b orbits the V = 11.685 G3 dwarf star GSC 3013-01229 on an eccentric ( e = 0 . 228 ± 0 . 016) orbit, with a period P = 4 . 124481 ± 0 . 000007 days, transit epoch T c = 2454996 . 41312 ± 0 . 00069, and transit duration 0 . 1530 ± 0 . 0027 days. The host star has a mass of 0 . 95 ± 0 . 04 M , radius of 1 . 10 ± 0 . 08 R , effective temperature 5588 ± 80 K, and metallicity [Fe / H] = +0 . 01 ± 0 . 08. The planetary companion has a mass of 4 . 063 ± 0 . 161 M J and a radius of 1 . 024 ± 0 . 092 R J yielding a mean density of 4 . 68 +1 . 59 − 0 . 99 gcm − 3 . HAT-P-21b is a borderline ob- ject between the pM and pL class planets, and the transits occur near apastron. HAT-P-22b orbits the bright V = 9.732 G5 dwarf star HD 233731 on a circular orbit, with a period P = 3 . 212220 ± 0 . 000009 days, transit epoch T c = 2454930 . 22001 ± 0 . 00025, and transit duration 0 . 1196 ± 0 . 0014 days. The host star has a mass of 0 . 92 ± 0 . 03 M , radius of 1 . 04 ± 0 . 04 R , effective temperature 5302 ± 80 K, and metallicity [Fe / H] = +0 . 24 ± 0 . 08. The planet has a mass of 2 . 147 ± 0 . 061 M J and a compact radius of 1 . 080 ± 0 . 058 R J yielding a mean density of 2 . 11 +0 . 40 − 0 . 29 gcm − 3 . The host star also harbors an M-dwarf companion at a wide separation. Finally, HAT-P-23b orbits the V = 12.432 G0 dwarf star GSC 1632-01396 on a close to circular orbit, with a period P = 1 . 212884 ± 0 . 000002 days, transit epoch T c = 2454852 . 26464 ± 0 . 00018, and transit duration 0 . 0908 ± 0 . 0007 days. The host star has a mass of 1 . 13 ± 0 . 04 M , radius of 1 . 20 ± 0 . 07 R , effective temperature 5905 ± 80 K, and metallicity [Fe / H] = +0 . 15 ± 0 . 04. The planetary companion has a mass of 2 . 090 ± 0 . 111 M J and a radius of 1 . 368 ± 0 . 090 R J yielding a mean density of 1 . 01 ± 0 . 18 g cm − 3 . HAT-P-23b is an inflated and massive hot Jupiter on a very short period orbit, and has one of the shortest characteristic infall times (7 . 5 +2 . 9 − 1 . 8 Myr) before it gets engulfed by the star

HAT-P-32b and HAT-P-33b: Two Highly Inflated Hot Jupiters Transiting High-jitter Stars

We report the discovery of two exoplanets transiting high-jitter stars. HAT-P-32b orbits the bright V = 11.289 late-F–early-G dwarf star GSC 3281-00800, with a period P = 2 . 150008 ± 0 . 000001 d. The stellar and planetary masses and radii depend on the eccentricity of the system, which is poorly constrained due to the high-velocity jitter ( ∼ 80 m s − 1 ). Assuming a circular orbit, the star has a mass of 1 . 16 ± 0 . 04 M and radius of 1 . 22 ± 0 . 02 R , while the planet has a mass of 0 . 860 ± 0 . 164 M J and a radius of 1 . 789 ± 0 . 025 R J . The second planet, HAT-P-33b, orbits the bright V = 11.188 late-F dwarf star GSC 2461-00988, with a period P = 3 . 474474 ± 0 . 000001 d. As for HAT-P-32, the stellar and planetary masses and radii of HAT-P-33 depend on the eccentricity, which is poorly constrained due to the high jitter ( ∼ 50 m s − 1 ). In this case, spectral line bisector spans (BSs) are significantly anti-correlated with the radial velocity residuals, and we are able to use this correlation to reduce the residual rms to ∼ 35 m s − 1 . We find that the star has a mass of 1 . 38 ± 0 . 04 M and a radius of 1 . 64 ± 0 . 03 R while the planet has a mass of 0 . 762 ± 0 . 101 M J and a radius of 1 . 686 ± 0 . 045 R J for an assumed circular orbit. Due to the large BS variations exhibited by both stars we rely on detailed modeling of the photometric light curves to rule out blend scenarios. Both planets are among the largest radii transiting planets discovered to date

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darnn. 1. Dawn. 2. A drink.Dawn, a drink.G.M. Story July 1959PRINTED ITEMNot usedNot usedNot usedChecked by Cathy Wiseman on Wed 17 Dec 201