- ID:
- ivo://CDS.VizieR/J/AJ/154/81
- Title:
- BVRI photometry of luminous stars in M31 and M33
- Short Name:
- J/AJ/154/81
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the first four years of BVRI photometry from an on-going survey to annually monitor the photometric behavior of evolved luminous stars in M31 and M33. Photometry was measured for 199 stars at multiple epochs, including 9 classic Luminous Blue Variables (LBVs), 22 LBV candidates, 10 post-RGB A/F type hypergiants, and 18 B[e] supergiants. At all epochs, the brightness is measured in the V-band and at least one other band to a precision of 0.04-0.10 mag down to a limiting magnitude of 19.0-19.5. Thirty three stars in our survey exhibit significant variability, including at least two classic LBVs caught in S Doradus-type outbursts. A hyperlinked version of the photometry catalog is at http://go.uis.edu/m31m33photcat
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Search Results
- ID:
- ivo://CDS.VizieR/J/other/BAJ/24.62
- Title:
- BVRI Photometry of 14 PMS stars
- Short Name:
- J/other/BAJ/24.6
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New photometric data from CCD multicolour BVRI observations of 14 pre-main sequence stars during the period from 2013 April to 2015 September are presented. The studied objects are located in the field of 'Gulf of Mexico' in the NGC 7000/IC 5070 star-forming complex. The stars from our study exhibit different types of photometric variability in all optical passbands. Using our long-term observations and data published by other authors, we tried to define the reasons for the observed brightness variations. On the basis of our new data previously unknown periodicity in the light curve of the star LkHa 189 (2.45-days) was registered.
- ID:
- ivo://CDS.VizieR/J/other/BAJ/22.3
- Title:
- BVRI photometry of 5 PMS stars
- Short Name:
- J/other/BAJ/22.3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new data from BVRI photometric observations of five PMS stars during the period from April 2013 to July 2014. The stars are located in the field of NGC 7000/IC 5070 ("Gulf of Mexico") - a region with active star formation. The presented paper is a continuation of our long-term photometric investigations of the young stellar objects in this region. The long-term multicolor photometric observations of PMS stars are very important for their exact classification. Our results show that the studied stars exhibit different types of photometric variability in all bands. We tried to classify them using our data from the long-term photometry and data published by other authors.
- ID:
- ivo://CDS.VizieR/J/other/NewA/17.46
- Title:
- BVR light curves of V1191 Cyg
- Short Name:
- J/other/NewA/17.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the analysis of photometric and spectroscopic variation, and orbital period study of the late-type contact binary system V1191 Cyg. The system is found to be a contact binary system having strange configuration with very small mass ratio and short orbital period comparing with the other members of the same group. We determined a new set of stellar physical parameters for hot and cooler companion as M_h_=0.13(1)M_{sun}_, M_c_=1.29(8)M_{sun}_, R_h_=0.52(15)R_{sun}_, R_c_=1.31(18)R_{sun}_, L_h_=0.46(25)L_{sun}_, L_c_=2.71(80)L_{sun}_, and the separation between the components a=2.20(8)R_{sun}_ from the simultaneous solution of the light and radial velocity curves. Analyses of the mid-eclipses time of the system indicate a period increase of dP/dt=1.3(1)x10^-6^days/yr that can be interpreted in terms of the high mass transfer dM/dt=2.0(4)x10^-7^M_{sun}_/yr from the less massive component to the more massive one.
- ID:
- ivo://CDS.VizieR/J/PAZh/21/596
- Title:
- BVR photometry of NGC 6584
- Short Name:
- J/PAZh/21/596
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Automatic stellar photographic BVR photometry reaching 1mag below the horizontal branch of NGC 6584, located at V~16.5mag, has been performed for this poorly studied globular cluster. One of the photoelectric standard stars used in our reductions appears to be variable. We also determined accurate coordinates of 52 variable stars in the cluster and around it.
- ID:
- ivo://CDS.VizieR/J/PASP/121/699
- Title:
- BVR photometry of V343 Ori
- Short Name:
- J/PASP/121/699
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- BVR light curves of V343 Orionis were observed with the 85cm telescope at Xinglong Station of the National Astronomical Observatories of the Chinese Academy of Sciences, in 2007 and 2008. Using the Wilson-Devinney program, the photometric solution of V343 Ori was first deduced from those observations. Photometric results indicated that V343 Ori is an A-subtype W Ursae Majoris binary, whose mass ratio and overcontact degree are q=0.253(+/-0.004) and f=86.9%(+/-2.1%), respectively.
- ID:
- ivo://CDS.VizieR/J/AJ/149/78
- Title:
- Candidate IR variables from SAGE-SMC survey
- Short Name:
- J/AJ/149/78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present our study on the infrared variability of point sources in the Small Magellanic Cloud (SMC). We use the data from the Spitzer Space Telescope Legacy Program "Surveying the Agents of Galaxy Evolution in the Tidally Stripped, Low Metallicity Small Magellanic Cloud" (SAGE-SMC) and the "Spitzer Survey of the Small Magellanic Cloud" (S^3^MC) survey, over three different epochs, separated by several months to 3 years. Variability in the thermal infrared is identified using a combination of Spitzer's InfraRed Array Camera 3.6, 4.5, 5.8, and 8.0{mu}m bands, and the Multiband Imaging Photometer for Spitzer 24{mu}m band. An error-weighted flux difference between each pair of three epochs ("variability index") is used to assess the variability of each source. A visual source inspection is used to validate the photometry and image quality. Out of ~2 million sources in the SAGE-SMC catalog, 814 meet our variability criteria. We matched the list of variable star candidates to the catalogs of SMC sources classified with other methods, available in the literature. Carbon-rich Asymptotic Giant Branch (AGB) stars make up the majority (61%) of our variable sources, with about a third of all of our sources being classified as extreme AGB stars. We find a small, but significant population of oxygen-rich (O-rich) AGB (8.6%), Red Supergiant (2.8%), and Red Giant Branch (<1%) stars. Other matches to the literature include Cepheid variable stars (8.6%), early type stars (2.8%), Young-stellar objects (5.8%), and background galaxies (1.2%). We found a candidate OH maser star, SSTISAGE1C J005212.88-730852.8, which is a variable O-rich AGB star, and would be the first OH/IR star in the SMC, if confirmed. We measured the infrared variability of a rare RV Tau variable (a post-AGB star) that has recently left the AGB phase. 59 variable stars from our list remain unclassified.
- ID:
- ivo://CDS.VizieR/J/MNRAS/376/313
- Title:
- Carbon star in Magellanic Cloud
- Short Name:
- J/MNRAS/376/313
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Dust radiative transfer models are presented for 60 carbon stars in the Magellanic Clouds (MCs) for which 535m Spitzer infrared spectrograph (IRS) spectra and quasi-simultaneous ground-based JHKL photometry are available. From the modelling, the luminosity and mass-loss rate are derived (under the assumption of a fixed expansion velocity and dust-to-gas ratio), and the ratio of silicon carbide (SiC) to amorphous carbon (AMC) dust is also derived. This ratio is smaller than observed in Galactic carbon stars, as has been noted before. Light curves for 36 objects can be retrieved from the massive compact halo object (MACHO) and optical gravitational lensing experiment (OGLE) data bases, and periods can be derived for all but two of these. Including data from the literature, periods are available for 53 stars.
- ID:
- ivo://CDS.VizieR/J/ApJ/814/71
- Title:
- Carina project IX: UBVI data of Carina variables
- Short Name:
- J/ApJ/814/71
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present new multiband (UBVI) time-series data of helium burning variables in the Carina dwarf spheroidal galaxy. The current sample includes 92 RR Lyrae --six of them are new identifications-- and 20 Anomalous Cepheids, one of which is new identification. The analysis of the Bailey diagram shows that the luminosity amplitude of the first overtone component in double-mode variables is located along the long-period tail of regular first overtone variables, while the fundamental component is located along the short-period tail of regular fundamental variables. This evidence further supports the transitional nature of these objects. Moreover, the distribution of Carina double-mode variables in the Petersen diagram (P_1_/P_0_ versus P_0_) is similar to metal-poor globulars (M15, M68), to the dwarf spheroidal Draco, and to the Galactic Halo. This suggests that the Carina old stellar population is metal-poor and affected by a small spread in metallicity. We use trigonometric parallaxes for five field RR Lyrae stars to provide an independent estimate of the Carina distance using the observed reddening free Period-Wesenheit [PW,(BV)] relation. Theory and observations indicate that this diagnostic is independent of metallicity. We found a true distance modulus of {mu}=20.01+/-0.02 (standard error of the mean)+/-0.05 (standard deviation) mag. We also provided independent estimates of the Carina true distance modulus using four predicted PW relations (BV, BI, VI, BVI) and we found: {mu}=(20.08+/-0.007+/-0.07)mag, {mu}=(20.06+/-0.006+/-0.06)mag, {mu}=(20.07+/-0.008+/-0.08)mag, and {mu}=(20.06+/-0.006+/-0.06)mag. Finally, we identified more than 100 new SX Phoenicis stars that together with those already known in the literature (340) make Carina a fundamental laboratory for constraining the evolutionary and pulsation properties of these transitional variables.
- ID:
- ivo://CDS.VizieR/J/ApJ/869/82
- Title:
- Carnegie-Chicago Hubble Program: RR Lyrae NIR obs.
- Short Name:
- J/ApJ/869/82
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present photometry of 30 Galactic RR Lyrae variables taken with HST WFC3/IR for the Carnegie-Chicago Hubble Program. These measurements form the base of the distance-ladder measurements that comprise a pure Population II base to a measurement of Ho at an accuracy of 3%. These data are taken with the same instrument and filter (F160W) as our observations of RR Lyrae stars in external galaxies so as to minimize sources of systematic error in our calibration of the extragalactic distance scale. We calculate mean magnitudes based on one to three measurements for each RR Lyrae star using star-by-star templates generated from densely time-sampled data at optical and midinfrared wavelengths. We use four RR Lyrae stars from our sample with well-measured HST parallaxes to determine a zero-point. This zero-point will soon be improved with the large number of precise parallaxes to be provided by Gaia. We also provide preliminary calibration with the TGAS and Gaia DR2 data, and all three zero points are in agreement, to within their uncertainties.