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1501. HARPS radial velocity follow up of TOI-1634
ID:
ivo://CDS.VizieR/J/AJ/162/79
Title:
HARPS radial velocity follow up of TOI-1634
Short Name:
J/AJ/162/79
Date:
11 Mar 2022
Publisher:
CDS
Description:
Studies of close-in planets orbiting M dwarfs have suggested that the M-dwarf radius valley may be well explained by distinct formation timescales between enveloped terrestrials and rocky planets that form at late times in a gas-depleted environment. This scenario is at odds with the picture that close-in rocky planets form with a primordial gaseous envelope that is subsequently stripped away by some thermally driven mass-loss process. These two physical scenarios make unique predictions of the rocky/enveloped transition's dependence on orbital separation such that studying the compositions of planets within the M-dwarf radius valley may be able to establish the dominant physics. Here, we present the discovery of one such keystone planet: the ultra-short-period planet TOI-1634b (P=0.989days, F=121F{Earth}, r_p_=1.790_-0.081_^+0.080^R{Earth}) orbiting a nearby M2 dwarf (K_s_=8.7, R_s_=0.450R{sun}, M_s_=0.502M{sun}) and whose size and orbital period sit within the M-dwarf radius valley. We confirm the TESS-discovered planet candidate using extensive ground-based follow-up campaigns, including a set of 32 precise radial velocity measurements from HARPS-N. We measure a planetary mass of 4.91_-0.70_^+0.68^M{Earth}, which makes TOI-1634b inconsistent with an Earth-like composition at 5.9{sigma} and thus requires either an extended gaseous envelope, a large volatile-rich layer, or a rocky composition that is not dominated by iron and silicates to explain its mass and radius. The discovery that the bulk composition of TOI-1634b is inconsistent with that of Earth supports the gas-depleted formation mechanism to explain the emergence of the radius valley around M dwarfs with M_s_<~0.5M{sun}.
1502. H-ATLAS search for strongly lensed galaxies
ID:
ivo://CDS.VizieR/J/ApJ/749/65
Title:
H-ATLAS search for strongly lensed galaxies
Short Name:
J/ApJ/749/65
Date:
21 Oct 2021
Publisher:
CDS
Description:
While the selection of strongly lensed galaxies (SLGs) with 500{mu}m flux density S_500_>100mJy has proven to be rather straightforward, for many applications it is important to analyze samples larger than the ones obtained when confining ourselves to such a bright limit. Moreover, only by probing to fainter flux densities is it possible to exploit strong lensing to investigate the bulk of the high-z star-forming galaxy population. We describe HALOS (the Herschel-ATLAS Lensed Objects Selection), a method for efficiently selecting fainter candidate SLGs, reaching a surface density of =~1.5-2/deg^2^, i.e., a factor of about 4-6 higher than that at the 100mJy flux limit. HALOS will allow the selection of up to ~1000 candidate SLGs (with amplifications {mu}>~2) over the full H-ATLAS survey area. Applying HALOS to the H-ATLAS Science Demonstration Phase field (=~14.4deg^2^) we find 31 candidate SLGs, whose candidate lenses are identified in the VIKING near-infrared catalog. Using the available information on candidate sources and candidate lenses we tentatively estimate a =~72% purity of the sample. As expected, the purity decreases with decreasing flux density of the sources and with increasing angular separation between candidate sources and lenses. The redshift distribution of the candidate lensed sources is close to that reported for most previous surveys for lensed galaxies, while that of candidate lenses extends to redshifts substantially higher than found in the other surveys. The counts of candidate SLGs are also in good agreement with model predictions. Even though a key ingredient of the method is the deep near-infrared VIKING photometry, we show that H-ATLAS data alone allow the selection of a similarly deep sample of candidate SLGs with an efficiency close to 50%; a slightly lower surface density (=~ 1.45/deg2) can be reached with a ~70% efficiency.
1503. HATNet Pleiades Rotation Period Catalogue
ID:
ivo://CDS.VizieR/J/MNRAS/408/475
Title:
HATNet Pleiades Rotation Period Catalogue
Short Name:
J/MNRAS/408/475
Date:
21 Oct 2021
Publisher:
CDS
Description:
Using data from the Hungarian-made Automated Telescope Network (HATNet) survey for transiting exoplanets, we measure photometric rotation periods for 368 Pleiades stars with 0.4~<M~<1.3M_{sun}_. We detect periodic variability for 74 per cent of the cluster members in this mass range that are within our field-of-view, and 93 per cent of the members with 0.7~<M~<1.0M_{sun}_. This increases, by a factor of 5, the number of Pleiades members with measured periods. We compare these data to the rich sample of spectroscopically determined projected equatorial rotation velocities (vsini) available in the literature for this cluster. Included in our sample are 14 newly identified probable cluster members which have proper motions, photometry and rotation periods consistent with membership.
1504. HATNET variability survey
ID:
ivo://CDS.VizieR/J/AJ/128/1761
Title:
HATNET variability survey
Short Name:
J/AJ/128/1761
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Hungarian-made Automated Telescope Network (HATnet) is an ongoing project to detect transiting extrasolar planets using small-aperture (11cm diameter) robotic telescopes. In this paper, we present the results from using image subtraction photometry to reduce a crowded stellar field observed with one of the HATnet telescopes (HAT-5). This field was chosen to overlap with the planned Kepler mission. We obtained I-band light curves for 98,000 objects in a 67 square degree field of view centered at J2000 ({alpha},{delta})=(19h44m00.0s, +37{deg}32'00.0"), near the Galactic plane in the constellations Cygnus and Lyra. These observations include 788 exposures of 5' length over 30-days. For the brightest stars (I~8.0) we achieved a precision of 3.5mmag, falling to 0.1mag at the faint end (I~14). From these light curves we identify 1617 variable stars, of which 1439 are newly discovered.
1505. HAT-P-18 and HAT-P-19 follow-up
ID:
ivo://CDS.VizieR/J/ApJ/726/52
Title:
HAT-P-18 and HAT-P-19 follow-up
Short Name:
J/ApJ/726/52
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report the discovery of two new transiting extrasolar planets. HAT-P-18b orbits the V=12.759 K2 dwarf star GSC 2594-00646, with a period P=5.508023+/-0.000006 days, transit epoch T_c_=2454715.02174+/-0.00020(BJD), and transit duration 0.1131+/-0.0009 days. The host star has a mass of 0.77+/-0.03M_{sun}_, radius of 0.75+/-0.04R_{sun}_, effective temperature 4803+/-80K, and metallicity [Fe/H]=+0.10+/-0.08. The planetary companion has a mass of 0.197+/-0.013M_J_ and radius of 0.995+/-0.052R_J_, yielding a mean density of 0.25+/-0.04g/cm^3^. HAT-P-19b orbits the V=12.901 K1 dwarf star GSC 2283-00589, with a period P=4.008778+/-0.000006 days, transit epoch T_c_=2455091.53417+/-0.00034(BJD), and transit duration 0.1182+/-0.0014 days. The host star has a mass of 0.84+/-0.04M_{sun}_, radius of 0.82+/-0.05R_{sun}_, effective temperature 4990+/-130K, and metallicity [Fe/H]=+0.23+/-0.08. The planetary companion has a mass of 0.292+/-0.018M_J_ and radius of 1.132+/-0.072R_J_, yielding a mean density of 0.25+/-0.04g/cm^3^. The radial velocity residuals for HAT-P-19 exhibit a linear trend in time, which indicates the presence of a third body in the system. Comparing these observations with theoretical models, we find that HAT-P-18b and HAT-P-19b are each consistent with a hydrogen-helium-dominated gas giant planet with negligible core mass. HAT-P-18b and HAT-P-19b join HAT-P-12b and WASP-21b in an emerging group of low-density Saturn-mass planets, with negligible inferred core masses. However, unlike HAT-P-12b and WASP-21b, both HAT-P-18b and HAT-P-19b orbit stars with super-solar metallicity.
1506. HAT-P-32 and HAT-P-33 follow-up
ID:
ivo://CDS.VizieR/J/ApJ/742/59
Title:
HAT-P-32 and HAT-P-33 follow-up
Short Name:
J/ApJ/742/59
Date:
21 Oct 2021
Publisher:
CDS
Description:
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+/-0.000001d. The stellar and planetary masses and radii depend on the eccentricity of the system, which is poorly constrained due to the high-velocity jitter (~80m/s). Assuming a circular orbit, the star has a mass of 1.16+/-0.04M_{sun}_ and radius of 1.22+/-0.02R_{sun}_, while the planet has a mass of 0.860+/-0.164M_J_ and a radius of 1.789+/-0.025R_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+/-0.000001d. 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 (~50m/s). 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 ~35m/s. We find that the star has a mass of 1.38+/-0.04M_{sun}_ and a radius of 1.64+/-0.03R_{sun}_ while the planet has a mass of 0.762+/-0.101M_J_ and a radius of 1.686+/-0.045R_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.
1507. HAT-P-42b and HAT-P-43b ri light curves
ID:
ivo://CDS.VizieR/J/A+A/558/A86
Title:
HAT-P-42b and HAT-P-43b ri light curves
Short Name:
J/A+A/558/A86
Date:
21 Oct 2021
Publisher:
CDS
Description:
We announce the discovery of two new transiting planets, and provide their accurate initial characterization. First identified from the HATNet wide-field photometric survey, these candidate transiting planets were then followed-up with a variety of photometric observations. Determining the planetary nature of the objects and characterizing the parameters of the systems were mainly done with the SOPHIE spectrograph at the 1.93m telescope at OHP and the TRES spectrograph at the 1.5m telescope at FLWO.
1508. HAT-P-41b transmission spectra with HST WFC3/UVIS
ID:
ivo://CDS.VizieR/J/AJ/159/204
Title:
HAT-P-41b transmission spectra with HST WFC3/UVIS
Short Name:
J/AJ/159/204
Date:
09 Dec 2021
Publisher:
CDS
Description:
The ultraviolet-visible wavelength range holds critical spectral diagnostics for the chemistry and physics at work in planetary atmospheres. To date, time-series studies of exoplanets to characterize their atmospheres have relied on several combinations of modes on the Hubble Space Telescope's STIS/COS instruments to access this wavelength regime. Here for the first time, we apply the Hubble WFC3/UVIS G280 grism mode to obtain exoplanet spectroscopy from 200 to 800nm in a single observation. We test the G280 grism mode on the hot Jupiter HAT-P-41b over two consecutive transits to determine its viability for the characterization of exoplanet atmospheres. We obtain a broadband transit depth precision of 29-33ppm and a precision of on average 200ppm in 10nm spectroscopic bins. Spectral information from the G280 grism can be extracted from both the positive and negative first-order spectra, resulting in a 60% increase in the measurable flux. Additionally, the first Hubble Space Telescope orbit can be fully utilized in the time-series analysis. We present detailed extraction and reduction methods for use by future investigations with this mode, testing multiple techniques. We find the results to be fully consistent with STIS measurements of HAT-P-41b from 310 to 800nm, with the G280 results representing a more observationally efficient and precise spectrum. HAT-P-41b's transmission spectrum is best fit with a model with Teq=2091K, high metallicity, and significant scattering and cloud opacity. With these first-of-their-kind observations, we demonstrate that WFC3/UVIS G280 is a powerful new tool to obtain UV-optical spectra of exoplanet atmospheres, adding to the UV legacy of Hubble and complementing future observations with the James Webb Space Telescope.
1509. HAT-P-30 follow-up photometry
ID:
ivo://CDS.VizieR/J/ApJ/735/24
Title:
HAT-P-30 follow-up photometry
Short Name:
J/ApJ/735/24
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report the discovery of HAT-P-30b, a transiting exoplanet orbiting the V=10.419 dwarf star GSC 0208-00722. The planet has a period P=2.810595+/-0.000005 days, transit epoch T_c_=2455456.46561+/-0.00037 (BJD), and transit duration 0.0887+/-0.0015 days. The host star has a mass of 1.24+/-0.04M_{sun}_, radius of 1.21+/-0.05R_{sun}_, effective temperature of 6304+/-88K, and metallicity [Fe/H]=+0.13+/-0.08. The planetary companion has a mass of 0.711+/-0.028M_J_ and radius of 1.340+/-0.065R_J_ yielding a mean density of 0.37+/-0.05g/cm^3^. We also present radial velocity measurements that were obtained throughout a transit that exhibit the Rossiter-McLaughlin effect. By modeling this effect, we measure an angle of {lambda}=73.5+/-9.0{deg} between the sky projections of the planet's orbit normal and the star's spin axis. HAT-P-30b represents another example of a close-in planet on a highly tilted orbit, and conforms to the previously noted pattern that tilted orbits are more common around stars with T_eff*_>~6250K.
1510. HAT-P-12 light curve
ID:
ivo://CDS.VizieR/J/ApJ/706/785
Title:
HAT-P-12 light curve
Short Name:
J/ApJ/706/785
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report on the discovery of HAT-P-12b, a transiting extrasolar planet orbiting the moderately bright V~12.8 K4 dwarf GSC 03033-00706, with a period P=3.2130598+/-0.0000021d, transit epoch T_c_=2454419.19556+/-0.00020 (BJD), and transit duration 0.0974+/-0.0006d. The host star has a mass of 0.73+/-0.02M_{sun}_, radius of 0.70^+0.02^_-0.01_R_{sun}_, effective temperature 4650+/-60K, and metallicity [Fe/H]=-0.29+/-0.05. We find a slight correlation between the observed spectral line bisector spans and the radial velocity, so we consider, and rule out, various blend configurations including a blend with a background eclipsing binary, and hierarchical triple systems where the eclipsing body is a star or a planet. We conclude that a model consisting of a single star with a transiting planet best fits the observations, and show that a likely explanation for the apparent correlation is contamination from scattered moonlight. Based on this model, the planetary companion has a mass of 0.211+/-0.012M_J_ and radius of 0.959^+0.029^_-0.021_R_J_ yielding a mean density of 0.295+/-0.025g/cm^3^. Comparing these observations with recent theoretical models, we find that HAT-P-12b is consistent with a ~1-4.5Gyr, mildly irradiated, H/He-dominated planet with a core mass M_C_<~10M_{earth}_.