Search

Start Over Subject astrometry Capability Type Simple Cone Search
321. Orientation of galaxies in galaxy clusters
ID:
ivo://CDS.VizieR/J/ApJ/723/985
Title:
Orientation of galaxies in galaxy clusters
Short Name:
J/ApJ/723/985
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present an analysis of the spatial orientations of galaxies in 247 optically selected rich Abell clusters which have at least 100 members in the considered area. We investigated the relation between angles that give information about galaxy angular momenta and the number of members in each structure. The position angles of the galaxies' major axes, as well as two angles describing the spatial orientation of the galaxy plane, were tested for isotropy by applying three different statistical tests. It is found that the values of the statistics increase with the amount of the galaxies' members, which is equivalent to the existence of a relation between anisotropy and the number of galaxies in a cluster. The search for connection between the galaxies' alignments and Bautz-Morgan (BM) morphological types of examined clusters showed a weak dependence. A statistically marginal relation between velocity dispersion and cluster richness was observed. In addition, it was found that the velocity dispersion decreases with BM type at almost 3{sigma} level. These results show the dependence of alignments with respect to clusters' richness, which can be regarded as an environmental effect.
322. Orion HST survey
ID:
ivo://CDS.VizieR/J/AJ/111/846
Title:
Orion HST survey
Short Name:
J/AJ/111/846
Date:
21 Oct 2021
Publisher:
CDS
Description:
We report on a survey of the brightest portions of the Orion Nebula made with the Wide Field Planetary Camera 2 of the Hubble Space Telescope. Fifteen paintings were made, each employing interference filters isolating the principal emission lines of HI, [NII], and [OIII] and another isolating an interval similar to the V bandpass. A careful survey of compact objects of stellar and nearly stellar appearance was made and astrometric solutions for individual fields were used to determine positions accurate to about 0.1". 344 stars were measured, down to about V=22. In addition to structures in several of the previously known Herbig-Haro objects, 145 compact sources that can be classified as proplyds were found. Proplyds are young stars surrounded by circumstellar material which is rendered visible by being in or near an HII region. In the central region, where detection of proplyds is easiest, almost all of the low-mass pre-main-sequence stars have obvious circumstellar material. The fraction falls as one views areas away from the dominant photoionizing star {theta}^1^C Ori. Six new dark disk proplyds are found, bringing the total to seven. These are objects showing only in silhouette against the bright background of the HII region. Most of these are elliptical in form, indicating that they are circumstellar disks. In addition to these compact sources, the new images allow detection of numerous large structures previously unreported from ground-based observations. These include shells and shocks apparently related to Herbig-Haro objects and high velocity outflows from young stellar objects.
323. Oxford 2 AC Zone Data Reduced to ACRS
ID:
ivo://CDS.VizieR/I/225
Title:
Oxford 2 AC Zone Data Reduced to ACRS
Short Name:
I/225
Date:
21 Oct 2021
Publisher:
CDS
Description:
The U.S. Naval Observatory is in the process of making new reductions of the Astrographic Catalogue (AC) using a modern reference system, the ACRS, which represents the system of the FK5. The data from the Oxford 2 Zone, whose plates are centered between declinations +32 and +33 degrees (eq. 1900), have been analyzed for scale, rotation, tilt, coma, magnitude equation, radial distortion and distortions introduced by the use of reseaux in the Carte du Ciel program. The result is a positional catalog of over 117,000 stars on eq. J2000.0, epoch of observation. Additionally, all stars have been matched with the Tycho Input Catalog (revised); those numbers have been added for additional identification purposes.
324. Oxford 1 AC Zone Data Reduced to ACRS
ID:
ivo://CDS.VizieR/I/224
Title:
Oxford 1 AC Zone Data Reduced to ACRS
Short Name:
I/224
Date:
21 Oct 2021
Publisher:
CDS
Description:
The U.S. Naval Observatory is in the process of making new reductions of the Astrographic Catalogue (AC) using a modern reference system, the ACRS, which represents the system of the FK5. The data from the Oxford 1 Zone, whose plates are centered between declinations +25 and +31 degrees (eq. 1900), have been analyzed for scale, rotation, tilt, coma, magnitude equation, radial distortion and distortions introduced by the use of reseaux in the Carte du Ciel program. The result is a positional catalog of over 277,000 stars on eq. J2000.0, epoch of observation. Additionally, all stars have been matched with the Tycho Input Catalog (revised); those numbers have been added for additional identification purposes.
325. Paris AC Zone Data Reduced to ACRS
ID:
ivo://CDS.VizieR/I/227
Title:
Paris AC Zone Data Reduced to ACRS
Short Name:
I/227
Date:
21 Oct 2021
Publisher:
CDS
Description:
The U.S. Naval Observatory is in the process of making new reductions of the Astrographic Catalogue (AC) using a modern reference system, the ACRS, which represents the system of the FK5. The data from the Paris Zone, whose plates are centered between declinations +18 and +24 degrees (eq. 1900), have been analyzed for scale, rotation, tilt, coma, magnitude equation, radial distortion and distortions introduced by the use of reseaux in the Carte du Ciel program. The result is a positional catalog of over 253,000 stars on eq. J2000.0, epoch of observation. Additionally, all stars have been matched with the Tycho Input Catalog (revised); those numbers have been added for additional identification purposes.
326. Perth 75 Catalogue
ID:
ivo://CDS.VizieR/I/97
Title:
Perth 75 Catalogue
Short Name:
I/97
Date:
21 Oct 2021
Publisher:
CDS
Description:
The catalog contains results of approximately 60000 photoelectric meridian circle observations made at the Perth Observatory for 1156 FK4 and 1433 FK4 Supplement stars south of declination +38 degrees. The catalog reports proper motions and positions at epoch and equinox B1950.0. The data used to derive the epoch 1950 positions are included in the catalog so that originally observed positions may be recomputed and used for geodetic purposes until the FK5 becomes available. The mean error of an individual position in this catalog is 0.07" in right ascension and 0.13" in declination at a zenith distance of 45 degrees, while the mean error of the PERTH 75 system is 0.05" in right ascension and 0.10" in declination. The positions do not contain the large systematic errors of the FK4 (Fricke and Kopff 1963), which can be, for example 0.3" in right ascension for declination < -75 degrees. Data in the catalog included FK4 (FK4S) number, observed visual magnitude, spectral type used for computing refraction, right ascension and declination (equinox and epoch B1950.0), annual proper motion, observed residuals, numbers of accepted observations, and code to indicate if parallax and/or radial velocity has been used in computing apparent positions.
327. Perth 70: Positions of 24900 Stars
ID:
ivo://CDS.VizieR/I/62C
Title:
Perth 70: Positions of 24900 Stars
Short Name:
I/62C
Date:
21 Oct 2021
Publisher:
CDS
Description:
(no description available)
328. PHA I observations
ID:
ivo://CDS.VizieR/J/A+AS/132/233
Title:
PHA I observations
Short Name:
J/A+AS/132/233
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Photoelectric Astrolabe Mark I (PHA I) has been revised with a new combined prism which could work as an almucantar with zenith distance of 45 degree, to measure continuous declinations at the latitude of Irkutsk, Russia ({phi}=52 degree). The PHA I has been working at the astronomical base of VS NIIFTRI in Irkutsk since Nov. 1995, based on an international cooperation agreement of near 4 years for star catalogue and EOP measurements. The first observing program was ended in June 1997, giving corrections in both right ascension and declination to 200 stars with no blind zone in declination determination, which most astrolabe catalogues in the world usually would have.
329. PHASES diff. astrometry data archive. II.
ID:
ivo://CDS.VizieR/J/AJ/140/1623
Title:
PHASES diff. astrometry data archive. II.
Short Name:
J/AJ/140/1623
Date:
21 Oct 2021
Publisher:
CDS
Description:
Differential astrometry measurements from the Palomar High-precision Astrometric Search for Exoplanet Systems have been combined with lower precision single-aperture measurements covering a much longer timespan (from eyepiece measurements, speckle interferometry, and adaptive optics) to determine improved visual orbits for 20 binary stars. In some cases, radial velocity observations exist to constrain the full three-dimensional orbit and determine component masses. The visual orbit of one of these binaries - {alpha} Com (HD 114378) - shows that the system is likely to have eclipses, despite its very long period of 26 years. The next eclipse is predicted to be within a week of 2015 January 24.
330. PHASES diff. astrometry data archive. V.
ID:
ivo://CDS.VizieR/J/AJ/140/1657
Title:
PHASES diff. astrometry data archive. V.
Short Name:
J/AJ/140/1657
Date:
21 Oct 2021
Publisher:
CDS
Description:
The Palomar High-precision Astrometric Search for Exoplanet Systems monitored 51 subarcsecond binary systems to evaluate whether tertiary companions as small as Jovian planets orbited either the primary or secondary stars, perturbing their otherwise smooth Keplerian motions. Six binaries are presented that show evidence of substellar companions orbiting either the primary or secondary star. Of these six systems, the likelihoods of two of the detected perturbations to represent real objects are considered to be "high confidence," while the remaining four systems are less certain and will require continued observations for confirmation.

Limit your search

more »

  • 2604

more »