- ID:
- ivo://CDS.VizieR/J/AcA/56/219
- Title:
- OGLE variable stars in NGC 6259
- Short Name:
- J/AcA/56/219
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a search for variable stars in the field of NGC6259. Altogether 85 variable stars have been discovered. 36 of them are eclipsing systems. This group contains 13 EA, 2 EB and 21 EW-type stars. Light curves of two variable stars resemble those of Miras. The remaining 47 variable stars detected in the field of this open cluster are most probably highly obscured red giants (OSARG, irregular). For all detected variable stars we provide their light curves, preliminary classification, discussion on the possible cluster membership, equatorial coordinates, finding charts and periods when possible.
Number of results to display per page
Search Results
252. Open cluster TR 10
- ID:
- ivo://CDS.VizieR/I/216A
- Title:
- Open cluster TR 10
- Short Name:
- I/216A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Positions for 979 stars in the area of Tr 10 are derived from fifteen plates taken recently with the ICDA refractor. For the determination of proper motions nine plates of the Cape Astrographic Catalogue are used as first epoch. The results make it appear doubtful that the object is a single cluster.
- ID:
- ivo://CDS.VizieR/J/ApJ/884/L55
- Title:
- Opt. follow-up of galaxies within S190814bv region
- Short Name:
- J/ApJ/884/L55
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- On 2019 August 14 the Laser Interferometer Gravitational Wave Observatory (LIGO) and the Virgo gravitational wave interferometer announced the detection of a binary merger, S190814bv, with a low false alarm rate of about 1 in 1.6x10^25^yr, a distance of 267+/-52Mpc, a 90% (50%) localization region of about 23 (5) deg^2^, and a probability of being a neutron star-black hole (NS-BH) merger of >99%. The LIGO/Virgo Collaboration (LVC) defines NS-BH such that the lighter binary member has a mass of <3M_{sun}_ and the more massive one has >5M_{sun}_, and this classification is in principle consistent with a BH-BH merger depending on the actual upper mass cutoff for neutron stars. Additionally, the LVC designated a probability that the merger led to matter outside the final BH remnant of <1%, suggesting that an electromagnetic (EM) counterpart is unlikely. Here we report our optical follow-up observations of S190814bv using the Magellan Baade 6.5m telescope to target all 96 galaxies in the Galaxy List for the Advanced Detector Era catalog within the 50% localization volume (representing about 70% of the integrated luminosity within this region). No counterpart was identified to a median 3{sigma} limiting magnitude of i=22.2 (M_i_~-14.9mag), comparable to the brightness of the optical counterpart of the binary neutron star merger GW170817 at the distance of S190814bv; similarly, we can rule out an on-axis jet typical of short GRBs. However, we cannot rule out other realistic models, such as a kilonova with only ~0.01M_{sun}_ of lanthanide-rich material, or an off-axis jet with a viewing angle of {theta}_obs_>~15{deg}.
- ID:
- ivo://CDS.VizieR/J/ApJ/848/L33
- Title:
- Opt. follow-up of GW events with LCO
- Short Name:
- J/ApJ/848/L33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an implementation of the Gehrels+ (2016ApJ...820..136G) galaxy-targeted strategy for gravitational-wave (GW) follow-up using the Las Cumbres Observatory global network of telescopes. We use the Galaxy List for the Advanced Detector Era (GLADE) galaxy catalog, which we show is complete (with respect to a Schechter function) out to ~300Mpc for galaxies brighter than the median Schechter function galaxy luminosity. We use a prioritization algorithm to select the galaxies with the highest chance of containing the counterpart given their luminosity, their position, and their distance relative to a GW localization, and in which we are most likely to detect a counterpart given its expected brightness compared to the limiting magnitude of our telescopes. This algorithm can be easily adapted to any expected transient parameters and telescopes. We implemented this strategy during the second Advanced Detector Observing Run (O2) and followed the black hole merger GW170814 and the neutron star merger GW170817. For the latter, we identified an optical kilonova/macronova counterpart thanks to our algorithm selecting the correct host galaxy fifth in its ranked list among the 182 galaxies we identified in the Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo localization.
- ID:
- ivo://CDS.VizieR/J/other/PABei/30.106
- Title:
- Optical identification of ROSAT AGN
- Short Name:
- J/other/PABei/30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The completeness of sample is especially important for the research of quasar and using data in one wavelength, such as in radio, infrared, optical or X-ray selection, to make candidate selection always suffers significant selection effect to some extent. Fortunately, some large area surveys have become increasingly prevalent across all wavelengths over the past decade, such as SDSS, NVSS, FIRST, RASS, etc. These surveys make it possible to select candidates in multiple wavelengths and the resulting sample is more complete.
- ID:
- ivo://CDS.VizieR/J/MNRAS/329/700
- Title:
- Optical IDs of JVAS using APM
- Short Name:
- J/MNRAS/329/700
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Files list1, list2, and list3 contain the lists of flat spectrum radio sources with their optical identifications from the APM (Automated Plate Measurement Facility at Cambridge) catalogue. List1 corresponds to the sources which are part of both the complete JVAS++ (a new complete sample constructed with selection criteria similar to those of JVAS -- Jodrell Bank VLA Astrometric Survey: S_5GHz_>200mJy, {alpha}_1.4-5GHz_>-0.5), and with the use of the more accurate GB6 and NVSS surveys) and original JVAS sample, List2 corresponds to sources which are only part of JVAS++, and List3 to sources which are only part of JVAS. The combination of List1 and List2 is a complete sample with S_6cm_>200mJy.
- ID:
- ivo://CDS.VizieR/J/ApJ/664/481
- Title:
- Optical/IR photometry of Collinder 69
- Short Name:
- J/ApJ/664/481
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present multiwavelength optical and IR photometry of 170 previously known low-mass stars and brown dwarfs of the 5Myr Collinder 69 cluster ({lambda} Orionis). The new photometry supports cluster membership for most of them, with less than 15% of the previous candidates identified as probable nonmembers. The near-IR photometry allows us to identify stars with IR excesses, and we find that the Class II population is very large, around 25% for stars (in the spectral range M0-M6.5) and 40% for brown dwarfs, down to 0.04M_{sun}_, despite the fact that the H{alpha} equivalent width is low for a significant fraction of them. In addition, there are a number of substellar objects, classified as Class III, that have optically thin disks. The Class II members are distributed in an inhomogeneous way, lying preferentially in a filament running toward the southeast. The IR excesses for the Collinder 69 members range from pure Class II (flat or nearly flat spectra longward of 1um), to transition disks with no near-IR excess but excesses beginning within the IRAC wavelength range, to two stars with excess only detected at 24um. Collinder 69 thus appears to be at an age where it provides a natural laboratory for the study of primordial disks and their dissipation.
- ID:
- ivo://CDS.VizieR/J/A+A/627/A33
- Title:
- Optically variable AGN in COSMOS field
- Short Name:
- J/A+A/627/A33
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The analysis of the variability of active galactic nuclei (AGNs) at different wavelengths and the study of possible correlations among different spectral windows are nowadays a major field of inquiry. Optical variability has been largely used to identify AGNs in multivisit surveys. The strength of a selection based on optical variability lies in the chance to analyze data from surveys of large sky areas by ground-based telescopes. However the effectiveness of optical variability selection, with respect to other multiwavelength techniques, has been poorly studied down to the depth expected from next generation surveys. Here we present the results of our r-band analysis of a sample of 299 optically variable AGN candidates in the VST survey of the COSMOS field, counting 54 visits spread over three observing seasons spanning >3yr. This dataset is >3 times larger in size than the one presented in our previous analysis (De Cicco et al., 2015, Cat. J/A+A/574/A112), and the observing baseline is 8 times longer. We push towards deeper magnitudes (r(AB)~23.5mag) compared to past studies; we make wide use of ancillary multiwavelength catalogs in order to confirm the nature of our AGN candidates, and constrain the accuracy of the method based on spectroscopic and photometric diagnostics. We also perform tests aimed at assessing the relevance of dense sampling in view of future wide-field surveys. We demonstrate that the method allows the selection of high-purity (>86%) samples. We take advantage of the longer observing baseline to achieve great improvement in the completeness of our sample with respect to X-ray and spectroscopically confirmed samples of AGNs (59%, vs. ~15% in our previous work), as well as in the completeness of unobscured and obscured AGNs. The effectiveness of the method confirms the importance to develop future, more refined techniques for the automated analysis of larger datasets.
- ID:
- ivo://CDS.VizieR/J/A+A/634/A50
- Title:
- Optically variable AGN in the VST/CDF-S
- Short Name:
- J/A+A/634/A50
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Variability has proven to be a powerful tool to detect active galactic nuclei (AGN) in multi-epoch surveys. The new-generation facilities expected to become operational in the next few years will mark a new era in time-domain astronomy and their wide-field multi-epoch campaigns will favor extensive variability studies. We present our analysis of AGN variability in the second half of the VST survey of the Wide Chandra Deep Field South (W-CDF-S), performed in the r band and covering a 2 sq. deg. area. The analysis complements a previous work, in which the first half of the area was investigated. We provide a reliable catalog of variable AGN candidates, which will be critical targets in future variability studies. We selected a sample of optically variable sources , and made use of infrared data from the Spitzer mission to validate their nature by means of color-based diagnostics. We obtain a sample of 782 AGN candidates among which 12 are classified as supernovae, 54 as stars, and 232 as AGN. We estimate a contamination <~ 20% and a completeness ~38% with respect to mid-infrared selected samples.
- ID:
- ivo://CDS.VizieR/J/A+AS/132/361
- Title:
- Optical observations of eight BL Lacs
- Short Name:
- J/A+AS/132/361
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Optical data in the Johnson's BV and Cousins' R bands are presented for eight X-ray selected BL Lacertae objects that have recently been pointed by the Satellite per Astronomia X `Beppo'(BeppoSAX). The observations were done with the 1.05m telescope of the Torino Astronomical Observatory and the observational periods include, or are close to, the satellite pointings. These data provide optical information on sources that have been rarely observed in the optical band. Moreover, they can be compared to the X-ray ones for a better understanding of the emission properties of these objects. Variability on short time scales (a few days) was found for MS 0317.0+1834, 1ES 0347-121, and MS 0737.9+7441. For a description of the (RI)c photometric system, see e.g. the General Catalog of Photometric Data <GCPD/54>
