- ID:
- ivo://CDS.VizieR/J/A+A/375/670
- Title:
- Photographic observations of radio stars
- Short Name:
- J/A+A/375/670
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- At the Engelhardt Astronomical Observatory (EAO), we observed photographic positions of 113 Galactic Radio Sources (GRS) in the system PPM catalogue (Rizvanov & Dautov, 1998, Kinematics and physics celestial bodies, 5, 457). Analysis of their accuracy is made by comparison with the Hipparcos catalogue (Perryman et al., 1997, Vat. <I/239>) and astrometric catalogue of radio stars in the radio window from the article of Walter et al. (1990A&AS...86..357W).
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/444/625
- Title:
- Photographic positions of the major planets
- Short Name:
- J/A+A/444/625
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We describe a large database of photographic observations of Solar System bodies obtained at the Engelhadt Astronomical Observatory (EnAO). We give a brief description of the methods of observations and the accuracy of their reduction with the PPM and Tycho-2 catalogues. The photographic positions of the major planets, except Jupiter, are in the system of the Tycho-2 catalogue and their comparison with DE200 ephemeris coordinates are given.
- ID:
- ivo://CDS.VizieR/J/ApJ/414/463
- Title:
- Planetary nebula system of NGC 5128
- Short Name:
- J/ApJ/414/463
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the result of a planetary nebula (PN) survey of the nearby giant elliptical galaxy NGC 5128 performed with CCD cameras at the prime focus of the CTIO 4m in telescope. By comparing CCD images centered on the characteristic emission line [O III] {lambda}5007{AA} and on the adjacent continuum, we identify a total of 785 PNs in areas extending 20kpc along the photometric major axis and covering the whole galaxy to 10kpc. From these data, we form a complete sample of 224 PN's extending to a dereddened limiting magnitude of m_5007_=24.8, which extends 1.5mag down the PN luminosity function (PNLF). Adopting a foreground extinction of E(B-V)=0.1, we derive a distance to the galaxy of 3.5+/-0.2Mpc, in excellent agreement with the surface brightness fluctuation method. No population effect on the bright cutoff of PNLF is observed in the isophotal radius range of 2-16kpc, but the luminosity specific PN density ({alpha}_2.5_) seems to increase with radius inside of 7kpc, in agreement with the {alpha}_2.5_-color relation observed for other galaxies.
- ID:
- ivo://CDS.VizieR/I/258
- Title:
- Pleiades positions and proper motions
- Short Name:
- I/258
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Based on a preliminary reference catalogue, combined with the catalogues PPM, ACRS and those in Eichhorn et al (1970, Cat. <I/90>), Jones (1973A&AS....9..313J) and Hertzsprung (1947AnLei..19a...1H), 33 exposures on 11 plates taken with the Zo-Se 40cm refractor (f=6895mm) in 86 years are reduced with the central overlapping technique, and high-precision positions and proper motions of 441 stars in the Pleiades astrometric standard region are obtained. The standard errors of star positions are less than +/-0.05arcsec, and the standard errors of proper motions for 90% stars in our reduction are less than +/-0.001arcsec/yr.
- ID:
- ivo://CDS.VizieR/J/A+A/570/A86
- Title:
- Pluto astrometry from 19yrs observations
- Short Name:
- J/A+A/570/A86
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present astrometric positions of Pluto, consistent with the International Celestial Reference System, from 4412 CCD frames observed over 120 nights with three telescopes at the Observatorio do Pico dos Dias in Brazil, covering a time span from 1995 to 2013, and also 145 frames observed over 11 nights in 2007 and 2009 with the ESO/MPG 2.2m telescope equipped with the Wide Field Imager (WFI). Our aim is to contribute to the study and improvement of the orbit of Pluto with new astrometric methods and positions.
- ID:
- ivo://CDS.VizieR/J/A+A/515/A32
- Title:
- Pluto, Charon, Nix, Hydra occultations 2008-15
- Short Name:
- J/A+A/515/A32
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We made the astrometry of 110GB of images with the Platform for Reduction of Astronomical Images Automatically (PRAIA). By relatively simple astrometric techniques, we treated the overlapping observations and derived a field distortion pattern for the WFI mosaic of CCDs to within 50mas precision. Positions were obtained in the UCAC2 frame with errors of 50mas for stars up to magnitude R=19, and 25mas up to R=17. New stellar proper motions were also determined with 2MASS and the USNO B1.0 catalog positions as first epoch. The catalog contains 2.24 million stars with proper motions, covering Pluto's sky path with 30 arcmin width. Its magnitude completeness is about R=18 with a limit about R=21. The catalog of star positions along Pluto's 2008-2015 sky path was built in the context of the investigation of Pluto and its satellites, aiming to support precise astrometric predictions for stellar occultations by Pluto, Charon, Hydra and Nix for the period 2008-2015. For that, we have carried out in 2007 an observational program at the ESO2p2/WFI instrument covering the sky path of Pluto from 2008 to 2015. We highlight the usefulness of this catalog as a reference frame for star/body astrometric follow-up before and after future stellar occultations involving the Pluto system. In this way, updates for the ephemeris offsets of these bodies and for the position of star candidates for occultations can be enhanced. Besides, the catalog also furnishes useful photometric information for field stars in the flux calibration of observed light curves. The prediction tables of stellar occultations by Pluto, Charon, Nix and Hydra for 2008-2015 were built for investigating the physical properties of Pluto and its satellites, for understanding in a broader sense transneptunian objects - keystones in the study of structure, origin and evolution of the Solar System. Our aim was to derive precise, astrometric predictions. We then constructed an astrometric star catalog in the UCAC2 system covering Pluto's sky path. For that, we have carried out in 2007 an observational program at the ESO2p2/WFI instrument covering the sky path of Pluto from 2008 to 2015. Based on the past 2005-8 occultations successfully predicted, recorded and fitted, a linear drift with time in declination with regard to DE418/plu017 ephemerides was determined for Pluto and used in the current predictions. For offset (mas)=A(t(yr)-2005.0)+B, we find A=+30.5+/-4.3mas/yr and B=-31.5+/-11.3mas, with standard deviation of 14.4mas for the offsets. For these past occultations, predictions and follow-up observations were made with the 0.6m and 1.6m telescopes at the Laboratorio Nacional de Astrofisica/Brazil. No ephemeris correction was applied for right ascension. Although an oscillation pattern related to an error in Pluto's heliocentric distance (geocentric parallax error) cannot be ruled out, none of the attempted models for this scenario could fit the more dispersed right ascension ephemeris offsets derived from the studied past occultations, at least not well below 50mas, in contrast with the standard deviation of only 14.4mas achieved for declination. The candidate stars listed in the prediction tables were searched using a proximity radius of 335mas with the geocentric apparent orbit (corrected by ephemeris offsets) of the body considered. This radius is about the apparent radius of Pluto (50mas) plus the apparent Earth radius (285mas) as projected in the sky plane at 31AU (Pluto-Earth distance for 2008-2015). No threshold in R magnitude was used in the search for candidates. Pluto is crossing interstellar clouds, so relatively faint R objects may turn out to be bright infrared stars, perfect targets for the SOFIA observatory and for ground-based instruments well equipped with H, J or K band detectors (H, J and K magnitudes are promptly available in the tables if the star belongs to the 2MASS). Besides, events may be also favored by slow shadow speeds of less than 20km/s. Also, no constraint on a geographic place was applied, as in principle SOFIA observations can be done from any sub-solar point on Earth. Events in daylight at sub-planet point were not excluded either, as they could yet be observable in the dark, right above the horizon, from places near the Earth terminator. We furnish here prediction tables for future and also for past stellar occultations covering the sky path by Pluto between 2008-2015. The importance of predictions for occultations still to come is obvious. But the predictions of past occultations are also useful for at least three reasons. First, they can be used by anyone as reference for ongoing fittings of light curves of recent past observed events. Second, they serve to derive ephemeris drifts by comparing expected and observed central instants and C/A values. Finally, they can be used as an external check for the accuracy and precision of our prediction tables. In a general sense, assuming a bulk error of 30mas for C/A from the estimated errors of the catalog star positions and from the errors of the derived ephemeris offsets, we can state that the shadow path uncertainties over Earth are on the order of less than 800km for the stellar occultation predictions of Pluto and Charon. Considering orbital issues and the smaller sizes of Nix and Hydra, the probability of success quoted for these two satellites are about 10-25%. This is not as high as hoped, but not despairingly small, especially if the event occurs above a dense, populated region in terms of astronomers, including amateurs.
- ID:
- ivo://CDS.VizieR/J/A+AS/118/105
- Title:
- Pluto 1991-1994 observations
- Short Name:
- J/A+AS/118/105
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- 55 equatorial geocentric coordinates of Pluto from the photographic observations for 1991-1994 are presented in the table. The observations were carried out by Latvian astronomers using the 80/120/240 cm Schmidt telescope at Baldone near Riga. 34 plates were measured and the positions of Pluto were reduced by using the 12-21 reference stars from catalogue of southern stars FOCAT-S, created at Pulkovo. The mean reduction errors vary from 0.23" to 0.34" for both coordinates. The obtained Pluto positions were compared with the ephemeris JPL DE200 (the residuals (O-C) were calculated). The increase of the average annual (O-C) residuals in RA, already noticed in previous works by the Pulkovo authors, is confirmed. From observations, represented in 1994 the (O-C) residuals with respect to DE200 have reached in RA +2.32+/-0.07" and in Dec. -0.74+/-0.07". More detailed information on obtaining the Pluto positions is given in Ryl'kov (1993) and Ryl'kov et.al. (1993).
- ID:
- ivo://CDS.VizieR/J/A+A/553/A14
- Title:
- Pluto's observations between 1997 and 2010
- Short Name:
- J/A+A/553/A14
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Because of Pluto's distance from the Sun, the Pluto system has not yet completed a revolution since its discovery, hence an uncertain heliocentric distance. In this paper, we present the fitting of our dynamical model ODIN (Orbite, Dynamique et Integration Numerique) to observations. The small satellites P4 and P5 are not taken into account. We fitted our model to the measured absolute coordinates (RA, DEC) of Pluto, and to the measured positions of the satellites relative to Pluto.
379. PNe in NGC 5128
- ID:
- ivo://CDS.VizieR/J/ApJS/88/423
- Title:
- PNe in NGC 5128
- Short Name:
- J/ApJS/88/423
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of planetary nebulae in the nearest giant elliptical galaxy NGC 5128. The catalog consists of positions and [O III]{lambda}5007 magnitudes for 785 planetary nebulae. This is the second largest catalog of planetaries, next only to that of the Milky Way. We also list the coordinates of 32 bright stars from the Guide Star Catalog and 80 additional reference stars in the survey fields for astrometric reference during future observations. The positions of the planetary nebulae are accurate to 0.2" with respect to the Guide Star Catalog in right ascension or declination.
- ID:
- ivo://CDS.VizieR/J/A+A/448/L9
- Title:
- Position catalogue of Swift XRT afterglows
- Short Name:
- J/A+A/448/L9
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalogue of refined positions of 68 gamma ray burst (GRB) afterglows observed by the Swift X-ray Telescope (XRT) from the launch up to 2005 Oct. 16. This is a result of the refinement of the XRT boresight calibration. We tested this correction by means of a systematic study of a large sample of X-ray sources observed by XRT with well established optical counterparts. We found that we can reduce the systematic error radius of the measurements by a factor of two, from 6.5 to 3.2 (90% of confidence). We corrected all the positions of the afterglows observed by XRT in the first 11 months of the Swift mission. This is particularly important for the 37 X-ray afterglows without optical counterpart. Optical follow-up of dark GRBs, in fact, will be more efficient with the use of the more accurate XRT positions.
