- ID:
- ivo://CDS.VizieR/J/A+A/520/A66
- Title:
- CoRoT-8b light and RV curves
- Short Name:
- J/A+A/520/A66
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of CoRoT-8b, a dense small Saturn-class exoplanet that orbits a K1 dwarf in 6.2 days, and we derive its orbital parameters, mass, and radius. We analyzed two complementary data sets: the photometric transit curve of CoRoT-8b as measured by CoRoT and the radial velocity curve of CoRoT-8 as measured by the HARPS spectrometer. We find that CoRoT-8b is on a circular orbit with a semi-major axis of 0.063+/-0.001AU. It has a radius of 0.57+/-0.02RJ, a mass of 0.22+/-0.03MJ, and therefore a mean density 1.6+/-0.1g/cm^3^. With 67% of the size of Saturn and 72% of its mass, CoRoT-8b has a density comparable to that of Neptune (1.76g/cm^3^). We estimate its content in heavy elements to be 47-63 Earth masses, and the mass of its hydrogen-helium envelope to be 7-23 Earth masses. At 0.063AU, the thermal loss of hydrogen of CoRoT-8b should be no more than about 0.1% over an assumed integrated lifetime of 3Ga.
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- ID:
- ivo://CDS.VizieR/J/AJ/146/113
- Title:
- Differential griz photometry of HATS-3
- Short Name:
- J/AJ/146/113
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery by the HATSouth survey of HATS-3b, a transiting extrasolar planet orbiting a V=12.4 F dwarf star. HATS-3b has a period of P=3.5479days, mass of M_p_=1.07M_J_, and radius of R_p_=1.38R _J_. Given the radius of the planet, the brightness of the host star, and the stellar rotational velocity (vsini=9.0km/s), this system will make an interesting target for future observations to measure the Rossiter-McLaughlin effect and determine its spin-orbit alignment. We detail the low-/medium-resolution reconnaissance spectroscopy that we are now using to deal with large numbers of transiting planet candidates produced by the HATSouth survey. We show that this important step in discovering planets produces logg and T_eff_ parameters at a precision suitable for efficient candidate vetting, as well as efficiently identifying stellar mass eclipsing binaries with radial velocity semi-amplitudes as low as 1km/s.
- ID:
- ivo://CDS.VizieR/J/AJ/147/144
- Title:
- Differential griz photometry of HATS-5
- Short Name:
- J/AJ/147/144
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of HATS-5b, a transiting hot Saturn orbiting a G-type star, by the HATSouth survey. HATS-5b has a mass of M_p_{approx}0.24M_J_, radius of R_p_{approx}0.91R_J_, and transits its host star with a period of P{approx}4.7634days. The radius of HATS-5b is consistent with both theoretical and empirical models. The host star has a V-band magnitude of 12.6, mass of 0.94M_{sun}_, and radius of 0.87R_{sun}_. The relatively high scale height of HATS-5b and the bright, photometrically quiet host star make this planet a favorable target for future transmission spectroscopy follow-up observations. We reexamine the correlations in radius, equilibrium temperature, and metallicity of the close-in gas giants and find hot Jupiter-mass planets to exhibit the strongest dependence between radius and equilibrium temperature. We find no significant dependence in radius and metallicity for the close-in gas giant population.
- ID:
- ivo://CDS.VizieR/J/A+A/501/785
- Title:
- Discovery and characterization of WASP-6b
- Short Name:
- J/A+A/501/785
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of WASP-6b, an inflated sub-Jupiter mass planet transiting every 3.3610060^+0.0000022^_-0.0000035_days a mildly metal-poor solar-type star of magnitude V=11.9. A combined analysis of the WASP photometry, high-precision followup transit photometry and radial velocities yield a planetary mass M_p_=0.503^+0.019^_-0.038_ and radius R_p_=1.224^+0.051^_0.052_, resulting in a density {rho}_p_=0.27{+/-}0.05{rho}_J_. The mass and radius for the host star are M_*_=0.88^+0.05^-0.08_M_{sun}_ and R_*_=0.870^0.025^_-0.036_R_{sun}_. The non-zero orbital eccentricity e=0.054^+0.018^_-0.015_ that we measure suggests that the planet underwent a massive tidal heating ~1Gyr ago that could have contributed to its inflated radius. High-precision radial velocities obtained during a transit allow us to measure a sky-projected angle between the stellar spin and orbital axis {beta}=11^+14^_-18_{deg}. In addition to similar published measurements, this result favors a dominant migration mechanism based on tidal interactions with a protoplanetary disk.
- ID:
- ivo://CDS.VizieR/J/A+A/613/A41
- Title:
- 5 exoplanet light and RV curves
- Short Name:
- J/A+A/613/A41
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The measurement of the orbital obliquity of hot Jupiters, with different physical characteristics, can provide clues to the mechanisms of migration and orbital evolution of this particular class of giant exoplanets. We aim to derive the degree of alignment between planetary orbit and stellar spin angular momentum vectors and look for possible links with other orbital and fundamental physical parameters of the star-planet system. Here we focus on the characterisation of five transiting planetary systems (HAT-P-3, HAT-P-12, HAT-P-22, WASP-39 and WASP-60) and the determination of their sky-projected planet orbital obliquity through the measurement of the Rossiter-McLaughlin effect. We used HARPS-N high-precision radial velocity measurements, gathered during transit events, to measure the Rossiter-McLaughlin effect in the target systems and determine the sky-projected angle between the planetary orbital plane and the stellar equator. The characterisation of stellar atmospheric parameters was performed exploiting the HARPS-N spectra, using line equivalent width ratios, and spectral synthesis methods. Photometric parameters of the five transiting exoplanets were re-analysed through 17 new light curves, obtained with an array of medium-class telescopes, and other light curves from the literature. Survey-time-series photometric data were analysed for determining the rotation periods of the five stars and their spin inclination. From the analysis of the Rossiter-McLaughlin effect we derived a sky-projected obliquity of {lambda}=21.2+/-8.7{deg}, {lambda=-54^+41^_-13_{deg}, {lambda=-2.1+/-3.0{deg}, lambda=0+/-11{deg} and lambda=-129+/-17{deg} for HAT-P-3 b, HAT-P-12 b, HAT-P-22 b, WASP-39 b and WASP-60 b, respectively. The latter value indicates that WASP-60 b is moving on a retrograde orbit. These values represent the first measurements of {lambda} for the five exoplanetary systems under study. The stellar activity of HAT-P-22 indicates a rotation period of 28.7+/-0.4-days, which allowed us to estimate the true misalignment angle of HAT-P-22 b, {psi}=24+/-18{deg}. The revision of the physical parameters of the five exoplanetary systems returned values fully compatible with those existing in the literature, with the exception of the WASP-60 system, for which, based on higher quality spectroscopic and photometric data, we found a more massive and younger star, and a larger and hotter planet.
- ID:
- ivo://CDS.VizieR/J/A+A/591/A55
- Title:
- Five transiting hot Jupiters discovered using WASP
- Short Name:
- J/A+A/591/A55
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have used photometry from the WASP-South instrument to identify 5 stars showing planet-like transits in their light curves. The planetary nature of the companions to these stars has been confirmed using photometry from the EulerCam instrument on the Swiss Euler 1.2-m telescope and the TRAPPIST telescope, and spectroscopy obtained with the CORALIE spectrograph. The planets discovered are hot Jupiter systems with orbital periods in the range 2.17 to 5.75 days, masses from 0.3M_{Jup}_ to 1.2M_{Jup}_ and with radii from 1R_{Jup}_ to 1.5R_{Jup}_. These planets orbit bright stars (V=11-13) with spectral types in the range F9 to G4. WASP-126 is the brightest planetary system in this sample and hosts a low-mass planet with a large radius (0.3M_{Jup}_, 0.95R_{Jup}_), making it a good target for transmission spectroscopy. The high density of WASP-129 A suggests that it is a helium-rich star similar to HAT-P-11 A. WASP-133 has an enhanced surface lithium abundance compared to other old G-type stars, particularly other planet host stars. These planetary systems are good targets for follow-up observations with ground-based and space-based facilities to study their atmospheric and dynamical properties.
- ID:
- ivo://CDS.VizieR/J/AJ/152/136
- Title:
- Follow-up photometry and spectroscopy of KELT-17
- Short Name:
- J/AJ/152/136
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of a hot Jupiter transiting the V=9.23mag main-sequence A-star KELT-17 (BD+14 1881). KELT-17b is a 1.31_-0.29_^+0.28^M_J_, 1.525_-0.060_^+0.065^R_J_ hot-Jupiter in a 3.08-day period orbit misaligned at -115.9{deg}+/-4.1{deg} to the rotation axis of the star. The planet is confirmed via both the detection of the radial velocity orbit, and the Doppler tomographic detection of the shadow of the planet during two transits. The nature of the spin-orbit misaligned transit geometry allows us to place a constraint on the level of differential rotation in the host star; we find that KELT-17 is consistent with both rigid-body rotation and solar differential rotation rates ({alpha}<0.30 at 2{sigma} significance). KELT-17 is only the fourth A-star with a confirmed transiting planet, and with a mass of 1.635_-0.061_^+0.066^M_{Sun}_, an effective temperature of 7454+/-49K, and a projected rotational velocity of vsinI_*_=44.2_-1.3_^+1.5^km/s; it is among the most massive, hottest, and most rapidly rotating of known planet hosts.
- ID:
- ivo://CDS.VizieR/J/ApJ/750/84
- Title:
- Follow-up photometry and velocity of Qatar 2
- Short Name:
- J/ApJ/750/84
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery and initial characterization of Qatar-2b, a hot Jupiter transiting a V = 13.3 mag K dwarf in a circular orbit with a short period, P_b_= 1.34 days. The mass and radius of Qatar-2b are M_P_ = 2.49 M_J_ and R_P_= 1.14 R_J_, respectively. Radial-velocity monitoring of Qatar-2 over a span of 153 days revealed the presence of a second companion in an outer orbit. The Systemic Console yielded plausible orbits for the outer companion, with periods on the order of a year and a companion mass of at least several M_J_. Thus, Qatar-2 joins the short but growing list of systems with a transiting hot Jupiter and an outer companion with a much longer period. This system architecture is in sharp contrast to that found by Kepler for multi-transiting systems, which are dominated by objects smaller than Neptune, usually with tightly spaced orbits that must be nearly coplanar.
- ID:
- ivo://CDS.VizieR/J/ApJ/710/1724
- Title:
- Follow-up photometry for HAT-P-11
- Short Name:
- J/ApJ/710/1724
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the discovery of HAT-P-11b, the smallest radius transiting extrasolar planet (TEP) discovered from the ground, and the first hot Neptune discovered to date by transit searches. HAT-P-11b orbits the bright (V=9.587) and metal rich ([Fe/H]=+0.31+/-0.05) K4 dwarf star GSC 03561-02092 with P=4.8878162+/-0.0000071 days and produces a transit signal with depth of 4.2mmag, the shallowest found by transit searches that is due to a confirmed planet. We present a global analysis of the available photometric and radial velocity (RV) data that result in stellar and planetary parameters, with simultaneous treatment of systematic variations. HAT-P-11b orbits in an eccentric orbit with e=0.198+/-0.046 and {omega}=355.2{deg}+/-17.3{deg}, causing a reflex motion of its parent star with amplitude 11.6+/-1.2m/s, a challenging detection due to the high level of chromospheric activity of the parent star. Our ephemeris for the transit events is T_c_=2454605.89132+/-0.00032 (BJD), with duration 0.0957+/-0.0012 days, and secondary eclipse epoch of 2454608.96+/-0.15 days (BJD).
- ID:
- ivo://CDS.VizieR/J/AJ/144/19
- Title:
- Follow-up photometry for HAT-P-34 through HAT-P-37
- Short Name:
- J/AJ/144/19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of four transiting extrasolar planets (HAT-P-34b-HAT-P-37b) with masses ranging from 1.05 to 3.33M_J_ and periods from 1.33 to 5.45days. These planets orbit relatively bright F and G dwarf stars (from V=10.16 to V=13.2). Of particular interest is HAT-P-34b which is moderately massive (3.33M_J_), has a high eccentricity of e=0.441+/-0.032 at a period of P=5.452654+/-0.000016days, and shows hints of an outer component. The other three planets have properties that are typical of hot Jupiters.