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- ID:
- ivo://CDS.VizieR/J/A+AS/49/715
- Title:
- New variable stars in Sgr B
- Short Name:
- J/A+AS/49/715
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- 621 new variable stars have been detected on plates obtained with the Schmidt telescopes of the Mount Palomar Observatory (1968) and of the European Southern Observatory (1976-1980). The astrometric measurements (ESO-CERN) and the photometrical ones (CDCA) which have followed the detection the variable stars (Observatoire de Lyon) have led to determine the parameters {alpha}, {delta}, l, b, R(Max), R(Min), {delta}m. So we notice that: - 379 variable stars have an amplitude of variation in magnitude between 0.5 and 2.0 (delm/N histogram). -The number of variable stars strongly decreases towards the great amplitudes. -The surface density of variable stars by square degree in this central galactic direction increases from 2 to 21 in the explored field of 5.5degx5.5deg size.
- ID:
- ivo://CDS.VizieR/J/AJ/117/1708
- Title:
- NGC 1741 HST photometry
- Short Name:
- J/AJ/117/1708
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We use Hubble Space Telescope (HST) Faint Object Camera (FOC) ultraviolet (UV) and WFPC2 optical images in conjunction with UV spectroscopic observations taken with the Goddard High Resolution Spectrograph to examine the star formation history and properties of the interacting galaxy system NGC 1741 in the Hickson Compact Group 31. The high spatial resolution afforded by HST has allowed us to identify a large number of starburst knots, or "superstar clusters" (SSCs), in the starburst regions of this system. Photometry of these SSCs in the UV and optical bands indicates that most of these objects have ages of a few Myr, with a few up to ~100Myr, and masses between 10^4^ and 10^6^M_{sun}_. The estimated age is confirmed by a spectral synthesis analysis of one knot for which we have obtained a UV spectrum. The V-band luminosity function of the SSCs is well represented by a power law {Phi}(L)~L^-{alpha}^ with an index of -1.85, with no evidence of a turnover brighter than the completeness limit. These properties are in good agreement with those found for SSCs in other starburst galaxies. Our results support the suggestion that some of these SSCs may be extremely young globular clusters formed in a relatively recent starburst episode that has been triggered by a merger event.
24. NOMAD Catalog
- ID:
- ivo://CDS.VizieR/I/297
- Title:
- NOMAD Catalog
- Short Name:
- I/297
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Naval Observatory Merged Astrometric Dataset (NOMAD) contains astrometric and photometric data for over 1 billion stars derived from the Hipparcos (I/239), Tycho-2 (I/259), UCAC2 (I/289), and USNO-B1.0 (I/284) catalogs for astrometry and optical photometry, supplemented by 2MASS (II/246) near-infrared photometry. For each unique star the "best" astrometric and photometric data are chosen from the source catalogs and merged into a single dataset. A sequence of priorities is followed and NOMAD contains flags to identify the source catalogs and gives cross-reference identifications. This first release of NOMAD is not a compiled catalog; that is, if a star is identified in more than 1 of the above mentioned catalogs, only 1 catalog entry is chosen. Thus the local and global systematic errors of the various source catalogs will be present in this version of NOMAD. All source catalogs astrometric data are on the International Celestial Reference System within the limitations of the source catalogs. For more information, see https://www.usno.navy.mil/USNO/astrometry/optical-IR-prod/nomad A dedicated remote query program can be downloaded from http://cdsweb.u-strasbg.fr/doc/cdsclient.html
- ID:
- ivo://CDS.VizieR/J/A+A/449/425
- Title:
- Optical identification of ROSAT-FSC sources
- Short Name:
- J/A+A/449/425
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Byurakan/Hamburg/ROSAT Catalogue (BHRC) of the optical identifications of X-ray sources is presented. The BHRC includes all 2791 sources from the ROSAT-FSC (<IX/29>) with |b|>30, DEC>0 and ROSAT count rate CR>0.04cts/s. The optical identifications were carried out by means of the Hamburg Quasar Survey (HQS) digitized spectroscopic plates, the DSS1 and DSS2 (blue, red, and IR) images, and other available data. We managed to identify 97% of sources (2696 sources) that are associated with 3202 optical objects. 2248 X-ray sources have a single optical counterpart, 144 have a double or multiple optical counterpart (binaries, galaxy groups etc.), and 304 have ambiguous identifications. The table gives all available multiwavelength data for the identified sources.
- ID:
- ivo://CDS.VizieR/J/MNRAS/275/591
- Title:
- Outer regions of Galactic Bulge
- Short Name:
- J/MNRAS/275/591
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Digitized UK Schmidt plate photometry, calibrated with CCD photometry, is obtained in 18 regions over the Bulge. Stars are selected for spectroscopic follow-up from with a carefully chosen colour-magnitude window, optimized for efficient detection of bulge K giants. Some 1500 stellar spectra are obtained with the AAT AUTOFIB facility. We derive a radial velocity and metallicity for each star, and quantify the uncertainties in these measurements. Luminosity classification is derived both by visual classification and by using an automated routine based on Principal Component Analysis. There are two basic results from this survey: the discovery of the Sagittarius dwarf galaxy described by Ibata, Gilmore and Irwin (1994Natur.370..194I), and a study of the Galactic Bulge by Ibata and Gilmore (1995MNRAS.275..605I) The catalogue contains coordinates, photometry, radial velocities, luminosity classification and chemical abundances for approximately 1500 stars in lines of sight towards the Galactic Bulge. A detailed description of the selection of these stars, the methods used to derive the data, and the reliability of the data, is presented in the paper.
- ID:
- ivo://CDS.VizieR/J/AJ/89/1707
- Title:
- Photographic observations of variable stars in M9
- Short Name:
- J/AJ/89/1707
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New observations from the southern hemisphere have been used to check the periods for the 11 RR Lyrae variables in and around the globular cluster Messier 9. The periods were determined previously with data from northern observatories where M9 can only be observed over a small range in hour angle. Three of the eleven published periods were found to be in error. As a result of this, the mean period of the RRc variables has been revised from 0.279d to 0.341d, the mean period of the RRab variables has been revised from 0.614d to 0.621d,and a star previously believed to be an RR Lyrae has been reclassified as a Population II Cepheid. One of the RRc variables may be a double-mode pulsator. Another variable was studied, but the data were not sufficient for determining its period.
- ID:
- ivo://CDS.VizieR/J/MNRAS/239/459
- Title:
- Photographic study of A2197 and A2199
- Short Name:
- J/MNRAS/239/459
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Radii, b26 magnitudes, (b-r) colors, position angles, and ellipticities have been measured on the plates of Palomar 48-inch Schmidt telescope taken in May 1976, for 6925 galaxies in a 5-sq deg field enclosing the close pair of rich clusters A2197 and A2199.
- ID:
- ivo://CDS.VizieR/J/PASP/105/78
- Title:
- Photometry in open cluster NGC 5822
- Short Name:
- J/PASP/105/78
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The study presents photoelectric photometry of stars in NGC 5822 on the UBVR and DDO systems. The BV data are employed to calibrate a photographic survey of the cluster, while UBV and DDO data are used to constrain the cluster reddening and metallicity. Taken in conjunction with previous photometric analysis, it is found that the cluster has a reddening of 0.15+/-0.015(pe) as defined for the stars at the turnoff, and a metallicity relative to the sun of -0.15+/-0.05(pe).
- ID:
- ivo://CDS.VizieR/J/AJ/64/28
- Title:
- Photometry in the globular cluster M22
- Short Name:
- J/AJ/64/28
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Photovisual and photographic magnitudes of more than 400 stars in the globular cluster M22 have been measured. The resulting color-magnitude diagram extends to slightly fainter than the RR Lyurae domain and is generally similar to those for other globular clusters, in particular most resembling the diagram for M13
