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1411. Far-UV stellar photometry
ID:
ivo://CDS.VizieR/J/ApJS/104/101
Title:
Far-UV stellar photometry
Short Name:
J/ApJS/104/101
Date:
21 Oct 2021
Publisher:
CDS
Description:
Far-ultraviolet photometry is presented for 121 objects in a 20deg diameter field centered on Rho Oph and for 649 objects in a field covering the Galactic center. Broadband magnitudes with effective wavelengths of 1375A and 1781A are given. The Galactic center field overlaps two fields which were discussed in an earlier paper. Eighty- eight percent of the ultraviolet objects in the Rho Oph field were identified with visible stars using the SIMBAD database, while only 9% of the objects are blends of early-type stars too close together to separate with our resolution. The photometric calibration was studied in detail, and corrections for nonlinearity were derived for the fields analyzed earlier as well as those discussed here. For stars in common between the Galactic center field and the previous fields, a comparison of the magnitudes yielded estimates of the internal errors of the magnitudes of sigma_1375=0.13mag and sigma_1781=0.21mag. A collated list of stars in the fields covering the Galactic center and incorporating the revised calibration is presented and compared with the S201 data of the same region. The properties of the sample of ultraviolet objects in the Rho Oph field are briefly commented upon.
1412. Fast-rotating nearby solar-type stars. I.
ID:
ivo://CDS.VizieR/J/A+A/384/491
Title:
Fast-rotating nearby solar-type stars. I.
Short Name:
J/A+A/384/491
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the results of high-resolution spectroscopic and high-precision photometric observations on a sample of 129 late-F and G-type nearby stars selected on the basis of their large rotational velocity. Using also data from the Hipparcos satellite, CORAVEL and from the ROSAT satellite database, we infer spectral types, compute radial velocities, vsini, Li abundances and X-ray luminosities and investigate the single or binary nature of the sample stars. Such a careful analysis of our sample shows a large fraction of binaries (~62%) and of young single disk stars. In particular, at least 9 stars can be considered bona-fide PMS or ZAMS objects, and 30 stars are identified as SBs for the first time. Information on the presence of Ca II K emission and on optical variability is given for some of the stars of the sample. The photometry has been obtained at the European Southern Observatory (ESO-La silla, Chile) during several observing runs (19/11-03/12 1993, 24/11-04/12 1994, 15-28/01/1995 and 1-12/10/1995), by using the 50cm ESO telescope. The figures were published in paper II.
1413. Fast transients in the Fornax cluster
ID:
ivo://CDS.VizieR/J/ApJ/682/1205
Title:
Fast transients in the Fornax cluster
Short Name:
J/ApJ/682/1205
Date:
21 Oct 2021
Publisher:
CDS
Description:
The luminosity gap between novae (M_R_<=-10) and supernovae (M_R_>=-14) has been well known since the pioneering research of Zwicky and Hubble. Nearby galaxy clusters and concentrations offer an excellent opportunity to search for explosions brighter than classical novae and fainter than supernovae. Here we present the results of a B-band survey of 23 member galaxies of the Fornax Cluster, performed at the Las Campanas 2.5m Irenee du Pont telescope. Observations with a cadence of 32 minutes discovered no genuine fast transient to a limiting absolute magnitude of M_B_=-9.3mag. We provide a detailed assessment of the transient detection efficiency and the resulting upper limits on the event rate as function of peak magnitude. Further, we discuss the discoveries of five previously unknown foreground variables which we identified as two flare stars, two W UMa-type eclipsing binaries and a candidate {delta} Scuti/SX Phe star.
1414. FAUST observations in 4th Galactic Quadrant
ID:
ivo://CDS.VizieR/J/MNRAS/313/641
Title:
FAUST observations in 4th Galactic Quadrant
Short Name:
J/MNRAS/313/641
Date:
21 Oct 2021
Publisher:
CDS
Description:
The UV observations of FAUST are analysed in four sky fields (Dor, Cen, M81 and Tel), located in the general direction of the Fourth Galactic Quadrant, where 777 UV sources are detected, about 50% more than detected originally by Bowyer et al. (1993ApJ...415..875B). Ground-based objective-prism information for two of the fields were used to select the best-matching optical objects with which to identify the UV sources. Using this, and correlations with existing catalogues, reliable identifications are presented for about 75% of the sources. Most of the remaining sources have assigned optical counterparts but, lacking additional information, we offer only plausible identifications. FAUST is a wide-field telescope (7.6{deg} diameter) designed to image diffuse and point sources in the wavelength range 140-180nm. The experiment, the mission and the data are described in a previous paper by Bowyer et al., 1993ApJ...415..875B .
1415. FAUST sources in NGC 4038-39 and 6752 direction
ID:
ivo://CDS.VizieR/J/MNRAS/324/580
Title:
FAUST sources in NGC 4038-39 and 6752 direction
Short Name:
J/MNRAS/324/580
Date:
21 Oct 2021
Publisher:
CDS
Description:
Analysis of ultraviolet (UV) observations with the FAUST shuttle-borne telescope toward the Antennae and NGC 6752 celestial regions resulted in the detection of 46 and 221 candidate sources respectively, for a signal-to-noise ratio of 8. We discuss the source detection process and the identification of UV sources with optical counterparts. Using correlations with existing catalogues, we present reliable identifications for approximately 60 per cent of the sources. We find that most identified objects are B, A and F stars. The remaining identified objects are galaxies, a white dwarf in a binary system, and two K-type stars. Nearly all of the remaining unidentified objects have assigned optical counterparts but, lacking additional information, we give these only as best estimates. With help from new diagnostic diagrams, we suggest that these unclassified objects are main-sequence (or giant) stars within the local spiral arm or halo; or other hot evolved objects within the local spiral arm. We discuss the nature of the objects found and compare our results with those predicted from spectral and Galactic models.
1416. FAUST UV sources towards Ophiuchus
ID:
ivo://CDS.VizieR/J/MNRAS/332/441
Title:
FAUST UV sources towards Ophiuchus
Short Name:
J/MNRAS/332/441
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present results of an analysis of a UV image in the direction of Ophiuchus, obtained with the FAUST instrument. The image contains 228 UV sources. Most of these are identified as normal early-type stars through correlations with catalogued objects. For the first time in this project we identify UV sources as such stars by selecting suitable candidates in crowded fields as the bluest objects in colour-colour diagrams using observations from the Wise Observatory. These candidates are then studied using low-resolution spectroscopy, which allows the determination of spectral types to an accuracy of about one-half class, for 60 stars. Synthetic photometry of spectral data is performed in order to predict the expected UV emission, on the basis of the photometric information. These results are used along with the Hipparcos/Tycho (<I/239>) information, to search for subluminous stars. The comparison of the predicted emission with the FAUST measured magnitudes allows us to select 12 stars as highly probable evolved hot stars. High signal-to-noise spectra are obtained for nine of these stars, and Balmer line profiles are compared with the prediction of atmosphere models and with the spectrum of real stellar atmospheres. Among the nine candidates, six are classified as previously unrecognized sdB stars, and two as white dwarfs. Our result indicates that indeed more bright subluminous stars are still unrecognized in the existing samples.
1417. FBS 13th list of late M and carbon stars
ID:
ivo://CDS.VizieR/J/other/Ap/45.322
Title:
FBS 13th list of late M and carbon stars
Short Name:
J/other/Ap/45.32
Date:
21 Oct 2021
Publisher:
CDS
Description:
The thirteenth list of faint late M and carbon type stars detected on the plates of the First Byurakan Spectral Sky Survey in zone +1{deg}<={delta}<=+13{deg} covering about 3118 sq. degrees is presented. From 285 stars, 161 are newly detected objects: they are 17 carbon stars, 25 carbon star candidates, and 117 M-type stars. The spectral type of two objects is assumed to be between M8 - M9 or late N-subtypes. Among 161 objects, 85 (66 PSC + 19 FSC) are unclassified IRAS sources. Accurate positions, spectral classes, red magnitudes, and color indices are given using several astronomical databases. Finding charts from DSS are given for the most interesting objects.
1418. FBS 14th list of late M and carbon stars
ID:
ivo://CDS.VizieR/J/other/Ap/46.475
Title:
FBS 14th list of late M and carbon stars
Short Name:
J/other/Ap/46.47
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the fourteenth list of faint late M and carbon type stars detected on the plates of the First Byurakan Spectral Sky Survey in the zone +13{deg}<=DE<=+33{deg} covering about 4736deg^2^. From 260 stars, 118 are newly detected objects: they are 19 carbon stars, 5 carbon star candidates, and 94 M-type stars. Among 118 detected objects 73 (57 PSC + 16 FSC) are unclassified IRAS sources. Accurate positions, spectral classes, red magnitudes, color indices, and near-infrared J, H and K photometry are given, using several astronomical databases. Finding charts from DSS are given for the most interesting objects.
1419. FBS 15th list of late M and carbon stars
ID:
ivo://CDS.VizieR/J/other/Ap/53.123
Title:
FBS 15th list of late M and carbon stars
Short Name:
J/other/Ap/53.12
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present the fifteenth list of faint late M and Carbon type stars detected on the Digitized First Byurakan Survey (DFBS) spectral plates in the zone with +45{deg}<={delta}<=+49{deg} covering 678.4{deg}^2^. Accurate DSS2 positions, USNO-B1.0 B, R, and I magnitudes, 2MASS near-infrared J, H, and Ks photometry, IRAS PSC/FSC fluxes (when available), approximate spectral types and luminosity class estimations are given for 72 objects from which 9 are new confirmed carbon stars and 63 are M-type stars. For seven Mirids with known pulsation periods the absolute luminosities are derived, using Period-Luminosity relations. Absolute visual magnitudes and distances for five M dwarfs are estimated, using V-I color index. The object FBS 0845+466 is a candidate carbon dwarf with distance r~72pc.
1420. FBS 11th list of late-type stars
ID:
ivo://CDS.VizieR/J/other/Ap/44.88
Title:
FBS 11th list of late-type stars
Short Name:
J/other/Ap/44.88
Date:
21 Oct 2021
Publisher:
CDS
Description:
The eleventh list of faint late M and carbon type stars detected on the plates of the First Byurakan Spectral Survey in zone -7{deg}<={delta}<=-3{deg} and covering about 1000 square degrees is presented. From 126 detected stars, 88 are newly discovered objects: they are 6 carbon stars, 8 carbon star candidates, and 74 M-type stars; among the latter 38 (26 PSC + 12 FSC) are unclassified IRAS sources, and one object is an unclassified ROSAT source. Distances to the 6 newly discovered early-type carbon stars are estimated. Equatorial coordinates, red magnitudes, and spectral classes determined from the Palomar E-charts are provided. The lack of optical counterparts on Palomar O and E maps for two detected late M-type stars indicates a large variability in brightnesses of these objects (amplitude not smaller than 7.0 magnitude).