- ID:
- ivo://CDS.VizieR/J/ApJ/728/138
- Title:
- Follow-up photometry of HAT-P-26
- Short Name:
- J/ApJ/728/138
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of HAT-P-26b, a transiting extrasolar planet orbiting the moderately bright V=11.744 K1 dwarf star GSC 0320-01027, with a period P=4.234516+/-0.000015 days, transit epoch T_c_=2455304.65122+/-0.00035 (BJD; Barycentric Julian dates throughout the paper are calculated from Coordinated Universal Time (UTC)), and transit duration 0.1023+/-0.0010 days. The host star has a mass of 0.82+/-0.03M_{sun}_, radius of 0.79^+0.10^_-0.04_R_{sun}_, effective temperature 5079+/-88K, and metallicity [Fe/H]=-0.04+/-0.08. The planetary companion has a mass of 0.059+/-0.007M_J_, and radius of 0.565^+0.072^_-0.032_R_J_ yielding a mean density of 0.40+/-0.10g/cm^3^. HAT-P-26b is the fourth Neptune-mass transiting planet discovered to date. It has a mass that is comparable to those of Neptune and Uranus, and slightly smaller than those of the other transiting Super-Neptunes, but a radius that is ~65% larger than those of Neptune and Uranus, and also larger than those of the other transiting Super-Neptunes. HAT-P-26b is consistent with theoretical models of an irradiated Neptune-mass planet with a 10M_{earth}_ heavy element core that comprises >~50% of its mass with the remainder contained in a significant hydrogen-helium envelope, though the exact composition is uncertain as there are significant differences between various theoretical models at the Neptune-mass regime. The equatorial declination of the star makes it easily accessible to both Northern and Southern ground-based facilities for follow-up observations.
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- ID:
- ivo://CDS.VizieR/J/AJ/145/5
- Title:
- Follow-up photometry of HATS-1
- Short Name:
- J/AJ/145/5
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of HATS-1b, a transiting extrasolar planet orbiting the moderately bright V=12.05 G dwarf star GSC 6652-00186, and the first planet discovered by HATSouth, a global network of autonomous wide-field telescopes. HATS-1b has a period of P{approx}3.4465days, mass of M_p_{approx}1.86M_J_, and radius of R_p_{approx}1.30R_J_. The host star has a mass of 0.99M_{sun}_ and radius of 1.04R_{sun}_. The discovery light curve of HATS-1b has near-continuous coverage over several multi-day timespans, demonstrating the power of using a global network of telescopes to discover transiting planets.
- ID:
- ivo://CDS.VizieR/J/A+A/506/359
- Title:
- FORS2 and HAWKI photometry of CoRoT-1
- Short Name:
- J/A+A/506/359
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present VLT eclipse photometry for the giant planet CoRoT-1b. We observed a transit in the R-band filter and an occultation in a narrow filter centered on 2.09{mu}m. Our analysis of this new photometry and published radial velocities, in combination with stellar-evolutionary modeling, leads to a planetary mass and radius of 1.07^+0.13^_-0.18_M_{Jup}_ and 1.45^+0.07^_-0.13_R_{Jup}, confirming the very low density previously deduced from CoRoT photometry. The large occultation depth that we measure at 2.09{mu}m (0.278^0.043^_-0.066_% ) is consistent with thermal emission and is better reproduced by an atmospheric model with no redistribution of the absorbed stellar flux to the night side of the planet.
- ID:
- ivo://CDS.VizieR/J/A+A/596/A47
- Title:
- FORS2 transmission spectroscopy of WASP-17b
- Short Name:
- J/A+A/596/A47
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present FORS2 (attached to ESO's Very Large Telescope) observations of the exoplanet WASP-17b during its primary transit, for the purpose of differential spectrophotometry analysis. We use the instrument in its Mask eXchange Unit (MXU) mode to simultaneously obtain low resolution spectra of the planet hosting star, as well as several reference stars in the field of view. The integration of these spectra within broadband and smaller 100{AA} bins provides us with 'white' and spectrophotometric light curves, from 5700 to 8000{AA}. Through modelling the white light curve, we obtain refined bulk and transit parameters of the planet, as well as wavelength-dependent variations of the planetary radius from smaller spectral bins through which the transmission spectrum is obtained. The inference of transit parameters, as well as the noise statistics, is performed using a Gaussian Process model. We achieve a typical precision in the transit depth of a few hundred parts per million from various transit light curves. From the transmission spectra we rule out a flat spectrum at >3{sigma} and detect marginal presence of the pressure-broadened sodium wings. Furthermore, we detect the wing of the potassium absorption line in the upper atmosphere of the planet with 3-{sigma} confidence, both facts pointing to a relatively shallow temperature gradient in the atmosphere. These conclusions are mostly consistent with previous studies of this exo-atmosphere, although previous potassium measurements have been inconclusive.
- ID:
- ivo://CDS.VizieR/J/A+A/510/A100
- Title:
- Four new SDSS eclipsing systems
- Short Name:
- J/A+A/510/A100
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photometry of nine cataclysmic variable stars identified by the Sloan Digital Sky Survey, aimed at measuring the orbital periods of these systems. Four of these objects show deep eclipses, from which we measure their orbital periods. The light curves of three of the eclipsing systems are also analysed using the LCURVE code, and their mass ratios and orbital inclinations determined. SDSS J075059.97+141150.1 has an orbital period of 134.1564+/-0.0008min, making it a useful object with which to investigate the evolutionary processes of cataclysmic variables. SDSS J092444.48+080150.9 has a period of 131.2432+/-0.0014min and is probably magnetic. The white dwarf ingress and egress phases are very deep and short, and there is no clear evidence that this object has an accretion disc. SDSS J115207.00+404947.8 and SDSS J152419.33+220920.1 are nearly identical twins, with periods of 97.5+/-0.4 and 93.6+/-0.5min and mass ratios of 0.14+/-0.03 and 0.17+/-0.03, respectively. Their eclipses have well-defined white dwarf and bright spot ingress and egress features, making them excellent candidates for detailed study. All four of the orbital periods presented here are shorter than the 2-3 hour period gap observed in the known population of cataclysmic variables.
- ID:
- ivo://CDS.VizieR/J/A+A/572/A93
- Title:
- Four new transiting planets
- Short Name:
- J/A+A/572/A93
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The characterization of four new transiting extrasolar planets is presented here. KOI-188b and KOI-195b are bloated hot Saturns, with orbital periods of 3.8 and 3.2-days, and masses of 0.25 and 0.34M_Jup_, respectively. They are located in the low-mass range of known transiting, giant planets. KOI-192b has a similar mass (0.29M_Jup_) but a longer orbital period of 10.3 days. This places it in a domain where only few planets are known. KOI-830b, finally, with a mass of 1.27M_Jup_ and a period of 3.5-days, is a typical hot Jupiter. The four planets have radii of 0.98, 1.09, 1.2, and 1.08R_Jup_, respectively. We detected no significant eccentricity in any of the systems, while the accuracy of our data does not rule out possible moderate eccentricities. The four objects were first identified by the Kepler Team as promising candidates from photometry of the Kepler satellite. We establish here their planetary nature thanks to the radial velocity follow-up we secured with the HARPS-N spectrograph at the Telescopio Nazionale Galileo. The combined analyses of the whole datasets allow us to fully characterize the four planetary systems. These new objects increase the number of well-characterized exoplanets for statistics, and provide new targets for individual follow-up studies. The pre-screening we performed with the SOPHIE spectrograph at the Observatoire de Haute-Provence as part of that study also allowed us to conclude that a fifth candidate, KOI-219.01, is not a planet but is a false positive.
- ID:
- ivo://CDS.VizieR/J/MNRAS/420/2580
- Title:
- Four transits of HAT-P-13
- Short Name:
- J/MNRAS/420/2580
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photometry of four transits of the planetary system HAT-P-13, obtained using defocused telescopes. We analyse these, plus nine data sets from the literature, in order to determine the physical properties of the system. The mass and radius of the star are M_A_=1.320+/-0.048+/-0.039M_{sun}} and R_A_=1.756+/-0.043+/-0.017R_{sun}_ (statistical and systematic error bars). We find the equivalent quantities for the transiting planet to be M_b_=0.906+/-0.024+/-0.018M_Jup_ and R_b_=1.487+/-0.038+/-0.015R_Jup_, with an equilibrium temperature of T'_eq_=1725+/-31K. Compared to previous results, which were based on much sparser photometric data, we find the star to be more massive and evolved, and the planet to be larger, hotter and more rarefied.
- ID:
- ivo://CDS.VizieR/J/ApJ/652/1715
- Title:
- Four transits of the exoplanet XO-1b
- Short Name:
- J/ApJ/652/1715
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present RIz photometry of four consecutive transits of the newly discovered exoplanet XO-1b. We improve on the estimates of the transit parameters, finding the planetary radius to be R_P_=1.184^0.028^_0.018_R_J_, and the stellar radius to be R*=0.928^+0.018^_0.013_R_{sun}_, assuming a stellar mass of M*=(1.00+/-0.03)M_{sun}_.
- ID:
- ivo://CDS.VizieR/J/ApJ/733/127
- Title:
- Four transits of WASP-4b
- Short Name:
- J/ApJ/733/127
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photometry of four transits of the exoplanet WASP-4b, each with a precision of approximately 500ppm and a time sampling of 40-60s. We have used the data to refine the estimates of the system parameters and ephemerides. During two of the transits we observed a short-lived, low-amplitude anomaly that we interpret as the occultation of a starspot by the planet. We also found evidence for a pair of similar anomalies in previously published photometry. The recurrence of these anomalies suggests that the stellar rotation axis is nearly aligned with the orbital axis, or else the starspot would not have remained on the transit chord. By analyzing the timings of the anomalies we find the sky-projected stellar obliquity to be {lambda}=-1^+14^_-12_degrees. This result is consistent with (and more constraining than) a recent observation of the Rossiter-McLaughlin effect. It suggests that the planet migration mechanism preserved the initially low obliquity, or else that tidal evolution has realigned the system. Future applications of this method using data from the CoRoT and Kepler missions will allow spin-orbit alignment to be probed for many other exoplanets.
- ID:
- ivo://CDS.VizieR/J/AJ/134/1133
- Title:
- Fraction of contact binary trojan asteroids
- Short Name:
- J/AJ/134/1133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of an optical light-curve survey of 114 Jovian Trojan asteroids conducted to determine the fraction of contact binaries. Sparse sampling was used to assess the photometric range of the asteroids, and those showing the largest ranges were targeted for detailed follow-up observations. This survey led to the discovery of two Trojan asteroids, (17365) and (29314), displaying large light-curve ranges (~1mag) and long rotation periods (<2rotations/day) consistent with a contact binary nature.
