- ID:
- ivo://CDS.VizieR/J/ApJ/721/412
- Title:
- Photometry of polar CV* 1RXS J173006.4+033813
- Short Name:
- J/ApJ/721/412
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of 1RXS J173006.4+033813, a polar cataclysmic variable with a period of 120.21 minutes. The white dwarf primary has a magnetic field of B=42^+6^_-5_MG and the secondary is an M3 dwarf. The system shows highly symmetric double-peaked photometric modulation in the active state as well as in quiescence. These arise from a combination of cyclotron beaming and ellipsoidal modulation. The projected orbital velocity of the secondary is K_2_=390+/-4km/s. We place an upper limit of 830+/-65pc on the distance.
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- ID:
- ivo://CDS.VizieR/J/AJ/155/257
- Title:
- Photometry & RV follow-up observations of K2-18
- Short Name:
- J/AJ/155/257
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- K2-18 is a nearby M2.5 dwarf, located at 34 pc and hosting a transiting planet that was first discovered by the K2 mission and later confirmed with Spitzer Space Telescope observations. With a radius of ~2 R_{Earth}_ and an orbital period of ~33 days, the planet lies in the temperate zone of its host star and receives stellar irradiation similar to that of Earth. Here we perform radial velocity follow-up observations with the visual channel of CARMENES with the goal of determining the mass and density of the planet. We measure a planetary semi-amplitude of K_b_~3.5 m/s and a mass of M_b_~9 M_{Earth}_, yielding a bulk density around {rho}_b_~4 g/cm^3^. This indicates a low-mass planet with a composition consistent with a solid core and a volatile-rich envelope. A signal at 9 days was recently reported using radial velocity measurements taken with the HARPS spectrograph. This was interpreted as being due to a second planet. We see a weaker, time- and wavelength-dependent signal in the CARMENES data set and thus favor stellar activity for its origin. K2-18 b joins the growing group of low-mass planets detected in the temperate zone of M dwarfs. The brightness of the host star in the near-infrared makes the system a good target for detailed atmospheric studies with the James Webb Space Telescope.
- ID:
- ivo://CDS.VizieR/J/AJ/159/173
- Title:
- Photometry & RVs of 4 dwarfs hosting giant planets
- Short Name:
- J/AJ/159/173
- Date:
- 09 Dec 2021
- Publisher:
- CDS
- Description:
- We report the discovery of four transiting giant planets around K-dwarfs. The planets HATS-47b, HATS-48Ab, HATS-49b, and HATS-72b have masses of 0.369_-0.021_^+0.031^M_J_, 0.243_-0.030_^+0.022^M_J_, 0.353_-0.027_^+0.038^M_J_, and 0.1254{+/-}0.0039M_J_, respectively, and radii of 1.117{+/-}0.014R_J_, 0.800{+/-}0.015R_J_, 0.765{+/-}0.013R_J_, and 0.7224{+/-}0.0032R_J_, respectively. The planets orbit close to their host stars with orbital periods of 3.9228days, 3.1317days, 4.1480days, and 7.3279days, respectively. The hosts are main-sequence K-dwarfs with masses of 0.674_-0.012_^+0.016^M_{odot}_, 0.7279{+/-}0.0066M_{odot}_, 0.7133{+/-}0.0075M_{odot}_, and 0.7311{+/-}0.0028, and with V-band magnitudes of V=14.829{+/-}0.010, 14.35{+/-}0.11, 14.998{+/-}0.040 and 12.469{+/-}0.010. The super-Neptune HATS-72b (a.k.a. WASP-191b and TOI294.01) was independently identified as a transiting planet candidate by the HATSouth, WASP, and TESS surveys, and we present a combined analysis of all of the data gathered by each of these projects (and their follow-up programs). An exceptionally precise mass is measured for HATS-72b thanks to high-precision radial velocity (RV) measurements obtained with VLT/ESPRESSO, FEROS, HARPS, and Magellan/PFS. We also incorporate TESS observations of the warm Saturn-hosting systems HATS-47 (a.k.a. TOI1073.01), HATS-48A, and HATS-49. HATS-47 was independently identified as a candidate by the TESS team, while the other two systems were not previously identified from the TESS data. The RV orbital variations are measured for these systems using Magellan/PFS. HATS-48A has a resolved 5.4" neighbor in Gaia DR2, which is a common-proper-motion binary star companion to HATS-48A with a mass of 0.22M_{odot}_ and a current projected physical separation of ~1400au.
- ID:
- ivo://CDS.VizieR/J/ApJ/854/109
- Title:
- Photometry & spectroscopy follow-up of MWC 882
- Short Name:
- J/ApJ/854/109
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Disks in binary systems can cause exotic eclipsing events. MWC 882 (BD-224376, EPIC 225300403) is such a disk-eclipsing system identified from observations during Campaign 11 of the K2 mission. We propose that MWC 882 is a post-Algol system with a B7 donor star of mass 0.542+/-0.053M_{sun}_ in a 72-day orbit around an A0 accreting star of mass 3.24+/-0.29M_{sun}_. The 59.9+/-6.2R_{sun}_ disk around the accreting star occults the donor star once every orbit, inducing 19-day long, 7% deep eclipses identified by K2 and subsequently found in pre-discovery All-Sky Automated Survey and All Sky Automated Survey for Supernovae observations. We coordinated a campaign of photometric and spectroscopic observations for MWC 882 to measure the dynamical masses of the components and to monitor the system during eclipse. We found the photometric eclipse to be gray to ~1%. We found that the primary star exhibits spectroscopic signatures of active accretion, and we observed gas absorption features from the disk during eclipse. We suggest that MWC 882 initially consisted of a ~3.6M_{sun}_ donor star transferring mass via Roche lobe overflow to a ~2.1M_{sun}_ accretor in a ~7-day initial orbit. Through angular momentum conservation, the donor star is pushed outward during mass transfer to its current orbit of 72 days. The observed state of the system corresponds with the donor star having left the red giant branch ~0.3Myr ago, terminating active mass transfer. The present disk is expected to be short-lived (10^2^yr) without an active feeding mechanism, presenting a challenge to this model.
- ID:
- ivo://CDS.VizieR/J/other/PBeiO/16.18
- Title:
- Physical data of the FK stars
- Short Name:
- J/other/PBeiO/16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The precise positions and proper motions (J2000.0) of 1535 Basic FK5 (FK4) stars in FK5 system (Cat. <I/149>) have been used in the reduction of local vertical monitoring and catalog observations at the Beijing Astronomical Observatory. The same data of 1987 FK4Sup stars, in which 980 stars denoted with "F" will be included in FK5, are also available recently from Heidelberg by courtesy of Prof Tong Fu, the Director of the Purple Mountain Observatory. The positions and proper motions of the other 1007 FK4Sup stars in FK5 system have been given by the Astronomisches Rechen-Institut in Heidelberg with comparatively low accuracy. However, the physical data, such as the visual magnitudes and the spectral types of these stars with rather larger uncertainties are originated from the Henry Draper Catalogue since the compilation of FK4 and FK4Sup (Cat. <I/143>). The more accurate visual magnitudes are available in the well-defined photoelectric system and the spectral types in MK-system that may be found, for example, in the Bright Star Catalogue (Cat. <V/50>) and a Supplement to this catalogue (Cat. <V/36>).
- ID:
- ivo://CDS.VizieR/J/A+A/587/A64
- Title:
- Physical properties of giant exoplanets
- Short Name:
- J/A+A/587/A64
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- While giant extrasolar planets have been studied for more than two decades now, there are still some open questions as to their dominant formation and migration processes, as well as to their atmospheric evolution in different stellar environments. In this paper, we study a sample of giant transiting exoplanets detected by the Kepler telescope with orbital periods up to 400 days. We first defined a sample of 129 giant-planet candidates that we followed up with the SOPHIE spectrograph (OHP, France) in a 6-year radial velocity campaign. This allowed us to unveil the nature of these candidates and to measure a false-positive rate of 54.6+/-6.5% for giant-planet candidates orbiting within 400 days of period. Based on a sample of confirmed or likely planets, we then derived the occurrence rates of giant planets in different ranges of orbital periods. The overall occurrence rate of giant planets within 400 days is 4.6+/-0.6%. We recovered, for the first time in the Kepler data, the different populations of giant planets reported by radial velocity surveys. Comparing these rates with other yields, we find that the occurrence rate of giant planets is lower only for hot Jupiters but not for the longer-period planets. We also derive a first measurement of the occurrence rate of brown dwarfs in the brown-dwarf desert with a value of 0.29+/-0.17%. Finally, we discuss the physical properties of the giant planets in our sample. We confirm that giant planets receiving moderate irradiation are not inflated, but we find that they are on average smaller than predicted by formation and evolution models. In this regime of low-irradiated giant planets, we find a possible correlation between their bulk density and the iron abundance of the host star, which needs more detections to be confirmed.
- ID:
- ivo://CDS.VizieR/J/A+A/640/A73
- Title:
- pi Men radial velocity curves
- Short Name:
- J/A+A/640/A73
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Measuring the geometry of multi-planet extrasolar systems can provide insight into their dynamical history and the processes of planetary formation. These types of measurements are challenging for systems that are detected through indirect techniques such as radial velocity and transit, having only been measured for a handful of systems to date. We aim to place constraints on the orbital geometry of the outer planet in the {pi} Mensae system, a G0V star at a distance of 18.3pc that is host to a wide-orbit super-Jovian (Msini=10.02+/-0.15M_Jup_) with a 5.7-year period and an inner transiting super-Earth (M=4.82+/-0.85M_{Earth}_) with a 6.3-d period. The reflex motion induced by the outer planet on the Mensae star causes a significant motion of the photocenter of the system on the sky plane over the course of the 5.7-year orbital period of the planet. We combined astrometric measurements from the Hipparcos and Gaia satellites with a precisely determined spectroscopic orbit in an attempt to measure this reflex motion, and in turn we constrained the inclination of the orbital plane of the outer planet. We measure an inclination of i_b_=49.9^+5.3^_-4.5_deg for the orbital plane of {pi} Mensae b, leading to a direct measurement of its mass of 13:01^+1.03^_-0.95_M_{Jup}_. We find a significant mutual inclination between the orbital planes of the two planets, with a 95% credible interval for i_mut_ of between 34.5{deg} and 140.6{deg} after accounting for the unknown position angle of the orbit of {pi} Mensae c, strongly excluding a co-planar scenario for the two planets within this system. All orbits are stable in the present-day configuration, and secular oscillations of planet c's eccentricity are quenched by general relativistic precession. Planet c may have undergone high eccentricity tidal migration triggered by Kozai-Lidov cycles, but dynamical histories involving disk migration or in situ formation are not ruled out. Nonetheless, this system provides the first piece of direct evidence that giant planets with large mutual inclinations have a role to play in the origins and evolution of some super-Earth systems.
- ID:
- ivo://CDS.VizieR/J/A+A/642/A31
- Title:
- pi Men radial velocity curves
- Short Name:
- J/A+A/642/A31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The bright star {pi} Men was chosen as the first target for a radial velocity follow-up to test the performance of ESPRESSO, the new high-resolution spectrograph at the ESO's Very-Large Telescope (VLT). The star hosts a multi-planet system (a transiting 4M_{earth}_ planet at ~0.07au, and a sub-stellar companion on a ~2100-day eccentric orbit) which is particularly appealing for a precise multi-technique characterization. With the new ESPRESSO observations, that cover a time span of 200days, we aim to improve the precision and accuracy of the planet parameters and search for additional low-mass companions. We also take advantage of new photometric transits of {pi} Men c observed by TESS over a time span that overlaps with that of the ESPRESSO follow-up campaign. We analyse the enlarged spectroscopic and photometric datasets and compare the results to those in the literature. We further characterize the system by means of absolute astrometry with Hipparcos and Gaia. We used the high-resolution spectra of ESPRESSO for an independent determination of the stellar fundamental parameters. We present a precise characterization of the planetary system around {pi} Men. The ESPRESSO radial velocities alone (37 nightly binned data with typical uncertainty of 10cm/s) allow for a precise retrieval of the Doppler signal induced by {pi} Men c. The residuals show an RMS of 1.2m/s, which is half that of the HARPS data and, based on them, we put limits on the presence of additional low-mass planets (e.g. we can exclude companions with a minimum mass less than ~2M_{earth}_ within the orbit of {pi} Men c). We improve the ephemeris of {pi} Men c using 18 additional TESS transits, and in combination with the astrometric measurements, we determine the inclination of the orbital plane of {pi} Men b with high precision (i_b_=45.8^+1.4^_-1.1_deg). This leads to the precise measurement of its absolute mass m_b_=14.1^+0.5^_-0.4_Mjup, indicating that {pi} Men b can be classified as a brown dwarf. {pi} Men represents a nice example of the extreme precision radial velocities that can be obtained with ESPRESSO for bright targets. Our determination of the 3-D architecture of the {pi} Men planetary system, and the high relative misalignment of the planetary orbital planes, put constraints and challenges to the theories of formation and dynamical evolution of planetary systems. The accurate measurement of the mass of {pi} Men b contributes to make the brown dwarf desert a bit greener.
- ID:
- ivo://CDS.VizieR/J/A+A/619/L10
- Title:
- pi Men radial velocity curves
- Short Name:
- J/A+A/619/L10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the confirmation and mass determination of {pi} Men c, the first transiting planet discovered by NASA's TESS space mission. {pi} Men is a naked-eye (V=5.65mag), quiet G0 V star that was previously known to host a sub-stellar companion ({pi} Men b) on a longperiod (Porb=2091-days), eccentric (e=0.64) orbit. Using TESS time-series photometry, combined with Gaia data, published UCLES at AAT Doppler measurements, and archival HARPS at ESO-3.6m radial velocities, we found that {pi} Men c is a close-in planet with an orbital period of Porb=6.27-days, a mass of Mc=4.52+/-0.81M_{Earth}_, and a radius of Rc=2.06+/-0.03R_{Earth}_. Based on the planet's orbital period and size, {pi} Men c is a super-Earth located at, or close to, the radius gap, while its mass and bulk density suggest it may have held on to a significant atmosphere. Because of the brightness of the host star, this system is highly suitable for a wide range of further studies to characterize the planetary atmosphere and dynamical properties. We also performed an asteroseismic analysis of the TESS data and detected a hint of power excess consistent with the seismic values expected for this star, although this result depends on the photometric aperture used to extract the light curve. This marginal detection is expected from pre-launch simulations hinting at the asteroseismic potential of the TESS mission for longer, multi-sector observations and/or for more evolved bright stars.
- ID:
- ivo://CDS.VizieR/J/A+A/626/A90
- Title:
- Pismis 18 photometry and radial velocities
- Short Name:
- J/A+A/626/A90
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Pismis 18 is a moderately populated, intermediate-age open cluster located within the solar circle at a Galactocentric distance of about seven kpc. Few open clusters have been studied in detail in the inner disc region before the Gaia-ESO Survey. New data from the Gaia-ESO Survey allowed us to conduct an extended radial velocity membership study as well as spectroscopic metallicity and detailed chemical abundance measurements for this cluster. Gaia-ESO Survey data for 142 potential members, lying on the upper main sequence and on the red clump, yielded radial velocity measurements, which, together with proper motion measurements from the Gaia Second Data Release (Gaia DR2), were used to determine the systemic velocity of the cluster and membership of individual stars. Photometry from Gaia DR2 was used to re-determine cluster parameters based on high confidence member stars only. Cluster abundance measurements of six radial-velocity member stars with UVES high-resolution spectroscopy are presented for 23 elements. The average radial velocity of 26 high confidence members is -27.5+/-2.5(std)km/s with an average proper motion of pmra=-5.65+/-0.08(std)mas/yr and pmdec=-2.29+/-0.11(std)mas/yr. According to the new estimates, based on high confidence members, Pismis 18 has an age of {tau}=700^+40^_-50_Myr, interstellar reddening of E(B-V)=0.562^+0.012^_-0.026_mag and a de-reddened distance modulus of DM_0_=11.96^+0.10^_-0.24_mag. The median metallicity of the cluster (using the six UVES stars) is [Fe/H]=+0.23+/-0.05dex, with [{alpha}/Fe]=0.07+/-0.13 and a slight enhancement of s- and r- neutron-capture elements. With the present work, we fully characterized the open cluster Pismis 18.We confirmed its present location in the inner disc. We estimated a younger age than the previous literature values and we gave, for the first time, its metallicity and its detailed abundances. Its [{alpha}/Fe] and [s-process/Fe], both slightly super-solar, are in agreement with other inner-disc open clusters observed by the Gaia-ESO survey.
