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4271. RVs and light curves for HATS-60-HATS-69
ID:
ivo://CDS.VizieR/J/AJ/157/55
Title:
RVs and light curves for HATS-60-HATS-69
Short Name:
J/AJ/157/55
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report the discovery of 10 transiting extrasolar planets by the HATSouth survey. The planets range in mass from the super-Neptune HATS-62b, with M_p_<0.179 M_J_, to the super-Jupiter HATS-66b, with M_p_=5.33 M_J_, and in size from the Saturn HATS-69b, with R_p_=0.94 R_J_, to the inflated Jupiter HATS-67b, with R_p_=1.69 R_J_. The planets have orbital periods between 1.6092 days (HATS-67b) and 7.8180 days (HATS-61b). The hosts are dwarf stars with masses ranging from 0.89 M_{sun}_ (HATS-69) to 1.56 M_{sun}_ (HATS-64) and have apparent magnitudes between V=12.276+/-0.020 mag (HATS-68) and V=14.095+/-0.030 mag (HATS-66). The super-Neptune HATS-62b is the least massive planet discovered to date with a radius larger than Jupiter. Based largely on the Gaia DR2 distances and broadband photometry, we identify three systems (HATS-62, HATS-64, and HATS-65) as having possible unresolved binary star companions. We discuss in detail our methods for incorporating the Gaia DR2 observations into our modeling of the system parameters and into our blend analysis procedures.
4272. RVs and RI-photometry of HATS-37 and HATS-38
ID:
ivo://CDS.VizieR/J/AJ/160/222
Title:
RVs and RI-photometry of HATS-37 and HATS-38
Short Name:
J/AJ/160/222
Date:
09 Mar 2022 22:00:00
Publisher:
CDS
Description:
We report the discovery of two transiting Neptunes by the HATSouth survey. The planet HATS-37Ab has a mass of 0.099{+/-}0.042M_Jup_ (31.5{+/-}13.4M{Earth}) and a radius of 0.606{+/-}0.016R_Jup_, and is on a P=4.3315day orbit around a V=12.266{+/-}0.030mag, 0.843_-0.012_^+0.017^M{odot} star with a radius of 0.877_-0.012_^+0.019^R{odot}. We also present evidence that the star HATS-37A has an unresolved stellar companion HATS-37B, with a photometrically estimated mass of 0.654{+/-}0.033M{odot}. The planet HATS-38b has a mass of 0.074{+/-}0.011M_Jup_ (23.5{+/-}3.5M{Earth}) and a radius of 0.614{+/-}0.017R_Jup_, and is on a P=4.3750day orbit around a V=12.411{+/-}0.030mag, 0.890_-0.012_^+0.016^M{odot} star with a radius of 1.105{+/-}0.016 R{odot}. Both systems appear to be old, with isochrone-based ages of 11.46_-1.45_^+0.79^Gyr, and 11.89{+/-}0.60Gyr, respectively. Both HATS-37Ab and HATS-38b lie in the Neptune desert and are thus examples of a population with a low occurrence rate. They are also among the lowest-mass planets found from ground-based wide-field surveys to date.
4273. RVs & V-band LCs of probable members of Cyg OB2
ID:
ivo://CDS.VizieR/J/ApJ/811/85
Title:
RVs & V-band LCs of probable members of Cyg OB2
Short Name:
J/ApJ/811/85
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Cygnus OB2 Association is one of the nearest and largest collections of massive stars in the Galaxy. Situated at the heart of the "Cygnus X" complex of star-forming regions and molecular clouds, its distance has proven elusive owing to the ambiguous nature of kinematic distances along this l~=80{deg} sightline and the heavy, patchy extinction. In an effort to refine the three-dimensional geometry of key Cygnus X constituents, we have measured distances to four eclipsing double-lined OB-type spectroscopic binaries that are probable members of Cyg OB2. We find distances of 1.33+/-0.17, 1.32+/-0.07, 1.44+/-0.18, and 1.32+/-0.13kpc toward MT91 372, MT91 696, CPR2002 A36, and Schulte 3, respectively. We adopt a weighted average distance of 1.33+/-0.06kpc. This agrees well with spectrophotometric estimates for the Association as a whole and with parallax measurements of protostellar masers in the surrounding interstellar clouds, thereby linking the ongoing star formation in these clouds with Cyg OB2. We also identify Schulte 3C (O9.5V), a 4" visual companion to the 4.75 day binary Schulte 3(A+B), as a previously unrecognized Association member.
4274. RV variability in SDSS dwarf carbon stars
ID:
ivo://CDS.VizieR/J/ApJ/877/44
Title:
RV variability in SDSS dwarf carbon stars
Short Name:
J/ApJ/877/44
Date:
21 Oct 2021
Publisher:
CDS
Description:
Dwarf carbon (dC) stars (main-sequence stars showing carbon molecular bands) were initially thought to be an oxymoron because only asymptotic giant branch (AGB) stars dredge carbon into their atmospheres. Mass transfer from a former AGB companion that has since faded to a white dwarf seems the most likely explanation. Indeed, a few types of giants known to show anomalous abundances- notably, the CH, Ba and CEMP-s stars-are known to have a high binary frequency. The dC stars may be the enhanced-abundance progenitors of most, if not all of these systems, but this requires demonstrating a high binary frequency for dCs. Here, for a sample of 240 dC stars targeted for repeat spectroscopy by the SDSS-IV's Time Domain Spectroscopic Survey, we analyze radial velocity (RV) variability to constrain the binary frequency and orbital properties. A handful of dC systems show large velocity variability (>100km/s). We compare the dCs to a control sample with a similar distribution of magnitude, color, proper motion, and parallax. Using Markov chain Monte Carlo methods, we use the measured {Delta}RV distribution to estimate the binary fraction and the separation distribution assuming both a unimodal and bimodal distribution. We find the dC stars have an enhanced binary fraction of 95%, consistent with them being products of mass transfer. These models result in mean separations of less than 1 au corresponding to periods on the order of 1 yr. Our results support the conclusion that dC stars form from close binary systems via mass transfer.
4275. RX J105453.3+552102 cluster SDSS photometry
ID:
ivo://CDS.VizieR/J/A+A/527/A143
Title:
RX J105453.3+552102 cluster SDSS photometry
Short Name:
J/A+A/527/A143
Date:
21 Oct 2021
Publisher:
CDS
Description:
The most accepted scenario for the origin of fossil groups is that they are galaxy associations in which the merging rate was fast and efficient. These systems have assembled half of their mass at early epoch of the Universe, subsequently growing by minor mergers, and therefore could contain a fossil record of the galaxy structure formation. We have started an observational project in order to characterize a large sample of fossil groups. In this paper we present the analysis of the fossil system RX J105453.3+552102.
4276. RZJHK photometry for stellar sources in Serpens
ID:
ivo://CDS.VizieR/J/A+A/513/A38
Title:
RZJHK photometry for stellar sources in Serpens
Short Name:
J/A+A/513/A38
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a deep optical/near-infrared imaging survey of the Serpens molecular cloud. This survey constitutes the complementary optical data to the Spitzer "Core To Disk" (c2d) Legacy survey in this cloud. The survey was conducted using the Wide Field Camera at the Isaac Newton Telescope. About 0.96 square degrees were imaged in the R and Z filters, covering the entire region where most of the young stellar objects identified by the c2d survey are located. 26524 point-like sources were detected in both R and Z bands down to R=24.5mag and Z=23mag with a signal-to-noise ratio better than 3. The 95% completeness limit of our catalog corresponds to 0.04 solar masses for members of the Serpens star forming region (age 2Myr and distance 260pc) in the absence of extinction. Adopting the typical extinction of the observed area (Av=7mag), we estimate a 95% completeness level down to 0.1 solar masses. The astrometric accuracy of our catalog is 0.4-arcsec with respect to the 2MASS catalog. Our final catalog contains J2000 celestial coordinates, magnitudes in the R and Z bands calibrated to the SDSS photometric system and, where possible, JHK magnitudes from 2MASS for sources in 0.96 square degrees in the direction of Serpens. This data product has been already used within the frame of the c2d Spitzer Legacy Project analysis in Serpens to study the star/disk formation and evolution in this cloud; here we use it to obtain new indications of the disk-less population in Serpens.
4277. SAGA: Stromgren survey of seismic KIC stars
ID:
ivo://CDS.VizieR/J/ApJ/787/110
Title:
SAGA: Stromgren survey of seismic KIC stars
Short Name:
J/ApJ/787/110
Date:
21 Oct 2021
Publisher:
CDS
Description:
Asteroseismology has the capability of precisely determining stellar properties that would otherwise be inaccessible, such as radii, masses, and thus ages of stars. When coupling this information with classical determinations of stellar parameters, such as metallicities, effective temperatures, and angular diameters, powerful new diagnostics for Galactic studies can be obtained. The ongoing Stromgren survey for Asteroseismology and Galactic Archaeology (SAGA) has the goal of transforming the Kepler field into a new benchmark for Galactic studies, similar to the solar neighborhood. Here we present the first results from a stripe centered at a Galactic longitude of 74{deg} and covering latitude from about 8{deg} to 20{deg}, which includes almost 1000 K giants with seismic information and the benchmark open cluster NGC 6819. We describe the coupling of classical and seismic parameters, the accuracy as well as the caveats of the derived effective temperatures, metallicities, distances, surface gravities, masses, and radii. Confidence in the achieved precision is corroborated by the detection of the first and secondary clumps in a population of field stars with a ratio of 2 to 1 and by the negligible scatter in the seismic distances among NGC 6819 member stars. An assessment of the reliability of stellar parameters in the Kepler Input Catalog is also performed, and the impact of our results for population studies in the Milky Way is discussed, along with the importance of an all-sky Stromgren survey.
4278. SagDIG carbon and oxygen stars
ID:
ivo://CDS.VizieR/J/A+A/572/A42
Title:
SagDIG carbon and oxygen stars
Short Name:
J/A+A/572/A42
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Sagittarius dwarf irregular (also known as SagDIG or UKS 1927-177) is a gas-rich, low-metallicity and star-forming galaxy, at the outskirts (D~1.1Mpc) of the Local Group. Projected relatively close to the Galactic center [(l,b)=(21.06,-16.29)] the resolved stellar populations of this galaxy reflects a strong Galactic foreground contamination, attributed to the thin and thick disk and the halo. This has so far hampered the reconstruction of its star formation and chemical enrichment history, and studies of individual stars. We have analyzed two ACS@HST data-sets (GO-9820 and GO-10472) that were collected in August 2003 and June 2005, having a ~1.85 years epoch separation. The data has allowed the derivation of the relative proper-motion for the SagDIG stellar population and reduction of the heavy foreground contamination. This provides a much clearer view of the red stellar populations (young RSG and intermediate-age AGB as well as the old RGB and AGB). The ACS/WFC data was collected in the F475W, F606W and F814W HST filters, and the published table provides a photometric calibration of the ACS/WFC filters that follows Bedin et al. (2003AJ....126..247B). This is based on the Vega spectrum and follows the recipes given by Holtzmann et al. (1995PASP..107..156H) for WFPC2, using the most updated in-flight characterization of the camera (Sirianni et al. 2005PASP..117.1049S). Besides the reported magnitudes and their relative errors, we also provide the pixel-based offset between the two F814W epochs, which is used to separate the SagDIG stellar population from the Galactic foreground (see Sec.3 of the paper for details).
4279. SAGE AGB candidates
ID:
ivo://CDS.VizieR/J/ApJ/723/1195
Title:
SAGE AGB candidates
Short Name:
J/ApJ/723/1195
Date:
21 Oct 2021
Publisher:
CDS
Description:
We combine variability information from the MAssive Compact Halo Objects survey of the Large Magellanic Cloud with infrared photometry from the Spitzer Space Telescope Surveying the Agents of a Galaxy's Evolution survey to create a data set of ~30000 variable red sources. We photometrically classify these sources as being on the first ascent of the red giant branch, or as being in one of three stages along the asymptotic giant branch (AGB): oxygen-rich, carbon-rich, or highly reddened with indeterminate chemistry ("extreme" AGB candidates). We present linear period-luminosity (P-L) relationships for these sources using eight separate infrared bands (J, H, Ks, 3.6, 4.5, 5.8, 8.0, and 24um) as proxies for the luminosity. We find that the wavelength dependence of the slope of the P-L relationship is different for different photometrically determined classes of AGB stars. Stars photometrically classified as O-rich show the least variation of slope with wavelength, while dust enshrouded extreme AGB stars show a pronounced trend toward steeper slopes with increasing wavelength. We find that O-rich AGB stars pulsating in the fundamental mode obey a period-magnitude relation with a slope of -3.41+/-0.04 when magnitude is measured in the 3.6um band, in contrast to C-rich AGB stars, which obey a relation of slope -3.77+/-0.05.
4280. SAGE calibration stars
ID:
ivo://CDS.VizieR/J/AJ/132/2268
Title:
SAGE calibration stars
Short Name:
J/AJ/132/2268
Date:
21 Oct 2021
Publisher:
CDS
Description:
We are performing a uniform and unbiased imaging survey of the Large Magellanic Cloud (LMC; ~7{deg}x7{deg}) using the IRAC (3.6, 4.5, 5.8, and 8um) and MIPS (24, 70, and 160um) instruments on board the Spitzer Space Telescope in the Surveying the Agents of a Galaxy's Evolution (SAGE) survey, these agents being the interstellar medium (ISM) and stars in the LMC. This paper provides an overview of the SAGE Legacy project, including observing strategy, data processing, and initial results. The observing strategy includes two epochs in 2005, separated by 3 months, that both mitigate instrumental artifacts and constrain source variability. The SAGE data are nonproprietary. The data processing includes IRAC and MIPS pipelines and a database for mining the point-source catalogs, which will be released to the community in support of Spitzer proposal cycles 4 and 5. We present initial results on the epoch 1 data for a region near N79 and N83. The MIPS 70 and 160um images of the diffuse dust emission of the N79/N83 region reveal a similar distribution to the gas emissions, especially the HI 21cm emission.