- 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.
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Search Results
- 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.
4583. FBS blue stellar objects
- ID:
- ivo://CDS.VizieR/J/other/Ap/42.1
- Title:
- FBS blue stellar objects
- Short Name:
- J/other/Ap/42.1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The second part of the First Byurakan Survey is aimed at detecting all bright (B<16.5) UV-excess starlike objects in a large area of the sky. By comparison with other major surveys such as the ROSAT All Sky Survey (Cat. <IX/10>, the ROSAT WGACAT (Cat. <IX/12>) catalogue of point sources, the IRAS (Cat. <II/125>) survey, the 6cm Green Bank (Cat. <VIII/52>, the 1.4GHz NRAO VLA (Cat. <J/AJ/115/1693>, and the 92cm Westerbork Northern sky surveys (Cat. <VIII/62>) and with the catalogue of mean UBV data on stars, we estimate the number of AGNs present in the FBS survey and its completeness. We have made spectroscopic observations of nine of the most promising FBS candidates. We have found six new QSOs, bringing the total number of known QSOs in this survey to 42. By comparison with the Bright Quasar Survey, we found that the completeness of this last survey is of the order of 70% rather than 30-50% as suggested by several authors.
- ID:
- ivo://CDS.VizieR/J/A+A/426/367
- Title:
- FBS blue stellar objects DSS1/DSS2 astrometry
- Short Name:
- J/A+A/426/367
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Accurate measurements of the positions of 1103 First Byurakan Survey (FBS) blue stellar objects (the Second part of the FBS, <II/223>) have been carried out on the DSS1 and DSS2 (red and blue images). To establish the accuracy of the DSS1 and DSS2, measurements have been made for 153 AGN for which absolute VLBI coordinates have been published. The rms errors are: 0.45" for DSS1, 0.33" for DSS2 red, and 0.59" for DSS2 blue in each coordinate, the corresponding total positional errors being 0.64", 0.46", and 0.83", respectively. The highest accuracy (0.42") is obtained by weighted averaging of the DSS1 and DSS2 red positions. It is shown that by using all three DSS images accidental errors can be significantly reduced. The comparison of DSS2 and DSS1 images made it possible to reveal positional differences and proper motions for 78 objects (for 62 of these for the first time), including new high-probability candidate white dwarfs, and to find objects showing strong variability, i.e. high-probability candidate cataclysmic variables.
- ID:
- ivo://CDS.VizieR/J/other/Ap/46.46
- Title:
- FBS. Blue stellar objects. XII
- Short Name:
- J/other/Ap/46.46
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The twelfth list of blue stellar objects in the second part of the First Byurakan Spectral Sky Survey (FBS) is presented. This list contains 143 objects in the region -3{deg}<DE<+1{deg} at high latitudes with an area of approximately 992 square degrees (62 fields). The objects have magnitudes V of 11.8-18.1 and B-V colors ranging from -0.82 to +0.81. Of the 143 objects, 51 have been discovered for the first time. Equatorial coordinates, V magnitudes, color indices, and preliminary classifications of the objects are given. DSS identification charts are given for the newly discovered objects.
- 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.
- 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.
- 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.
- ID:
- ivo://CDS.VizieR/J/other/Ap/44.328
- Title:
- FBS 12th list of late-type stars
- Short Name:
- J/other/Ap/44.32
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The twelfth list of faint late M and carbon type stars detected on the plates of the First Byurakan Spectral Survey in zone -30{deg}<={delta}<=1{deg} covering about 1070 sq. degrees is presented. From 86 detected stars, 57 are newly discovered objects: they are 3 R-type carbon stars, 2 carbon star candidates and 52 M-type stars. Among the latter 34 (28 PSC + 6 FSC) are unclassified IRAS sources. Equatorial coordinates, spectral classes, color indices, and red magnitudes determined from the Palomar E-charts are presented.
- 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).