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TD1 Stellar Ultraviolet Fluxes Catalog

The Belgian/UK Ultraviolet Sky Survey Telescope (S2/68) in the ESRO TD1 satellite carried out a controlled scan of the entire sky. It measured the absolute ultraviolet flux distribution between 2740A and 1350A of point sources down to 10th visual magnitude for unreddened early B stars. The S2/68 experiment has been described by Boksenberg et al. (1973MNRAS.163..291B), and the absolute calibration by Humphries et al. (1976A&A....49..389H). The TD1 Catalog of Stellar Ultraviolet Fluxes represents results from the sky-scan experiment on the TD1 satellite of the European Space Research Organization (ESRO), now part of ESA. It lists the absolute fluxes, in four passbands, for 31,215 stars: <pre> Passband Center: 274.0nm 236.5nm 196.5nm 156.5nm Effective Width: 31.0nm 33.0nm 33.0nm 33.0nm </pre> The stars have been selected subject to the constraint that the signal-to-noise ratio should be at least 10.0 in any one of the four passbands. Null values of a flux field and an error field indicate there are no valid data for the star. This usually arises with close pairs of stars whose spectra overlap. Five standard flux error values are greater than 99.99, and were too large for the format of the flux field in the original table. Thus, the flux error values which were greater than 99.99 are given as 99.99. Many of the fainter stars of spectral type later than A5 do not have significant signals in all of the spectrophotometric channels (particularly the 1565A channel). Consequently, after the removal of the background, they can randomly give rise to small negative values of flux. Those negative values were not suppressed, but are given together with their error, as they can be significant when considered as part of a statistical sample. Although the sky coverage is essentially complete, the catalog does not contain the fluxes for all stars that fall within the limit of the sensitivity of the instrument. If any star expected to be present is missing, then its signal is probably blended with that of a nearby star, in which case the data have been discarded. The original contents of the HEASARC's TD1 database table came from a magnetic tape sent to NASA/Goddard Space Flight Center by Dr. G.I. Thompson of the Royal Observatory in Edinburgh, Scotland. The HEASARC recreated this database table in August 2005, based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/II/59B">CDS Catalog II/59B</a> file catalog.dat.gz, in an effort to modernize its parameter names and documentation, as well as to add Galactic coordinates. The data in the CDS version originally came from "Selected Astronomical Catalogs" Vol. 1 CD-ROM released by the NASA Astronomical Data Center (ADC) in 1991. This is a service provided by NASA HEASARC .

CASSINI JUP UVIS SOLAR STELLAR BRIGHTNESS TIME SERIES 1.0

Photometric observations of stellar occultations by Saturnian rings, satellites, atmospheres, and Jovian atmosphere.

Spitzer Survey of Stellar Structure in Galaxies Catalog

The Spitzer Survey of Stellar Structure in Galaxies (S4G) is a volume-, magnitude-, and size-limited survey of over 2300 nearby galaxies at 3.6 and 4.5 microns. This is an extremely deep survey reaching an unprecedented 1 sigma surface brightness limit of μ3.6(AB) = 27 mag arcsec-2. This translates to a stellar surface density of << 1 Msun pc-2.The S4G Catalog provides photometry and model parameters derived from the IRAC images, as well as a link to the summary and data access page for each galaxy and a variety of quantities taken from previously published work.

ASTEROID ALBEDOS FROM STELLAR OCCULTATIONS

This data set contains albedos for 57 asteroids determined from diameters obtained from stellar occultations. These albedos are from Shevchenko and Tedesco (2006).

CASSINI ORBITER SATURN UVIS STELLAR RING OCC 2004-2017

This data set contains derived radial occultation profiles of the rings of Saturn based on stellar occultation observations made with the Cassini UVIS instrument between October 2004 and August 2017.

RCW 38 Young Stellar Objects Catalog

This table contains some of the results from a study of the structure of the high-mass star-forming region RCW 38 and the spatial distribution of its young stellar population. Spitzer Infrared Array Camera (IRAC) photometry (3-8 micron) is combined with Two Micron All Sky Survey (2MASS) near-IR data to identify young stellar objects (YSOs) by IR-excess emission from their circumstellar material. Chandra X-ray data are used to identify class III pre-main-sequence stars lacking circumstellar material. The authors identify 624 YSOs: 23 class 0/I and 90 flat spectrum (FS) protostars, 437 class II stars, and 74 class III stars. They also identify 29 (27 new) O star candidates over the IRAC field. Seventy-two stars exhibit IR-variability, including 7 class 0/I and 12 flat spectrum YSOs. A further 177 tentative candidates are identified by their location in the IRAC [3.6] versus [3.6]-[5.8] color-magnitude diagram. The authors find strong evidence of subclustering in the region. Three subclusters were identified surrounding the central cluster, with massive and variable stars in each subcluster. The central region shows evidence of distinct spatial distributions of the protostars and pre-main-sequence stars. A previously detected IR cluster, DB2001_Obj36, has been established as a subcluster of RCW 38. This suggests that star formation in RCW 38 occurs over a more extended area than previously thought. The gas-to-dust ratio is examined using the X-ray derived hydrogen column density, NH and the K-band extinction, and found to be consistent with the diffuse interstellar medium, in contrast with Serpens and NGC 1333. The authors posit that the high photoionizing flux of massive stars in RCW 38 affects the agglomeration of the dust grains. This table contains the list of 624 young stellar objects (given in Tables 3 and 4 of the reference paper) found among the Spitzer sources in the field of RCW 38 using the two selection techniques described in Section 3 of the reference paper: (1) selection of stars with IR excesses in IR color-color diagrams, and (2) identification of X-ray luminous YSOs by comparing X-ray sources with IR detections. The latter technique was used to identify Type III YSOs lacking emission from a dusty disk. This table does NOT contain (i) the 177 candidate YSOs listed in Table 5 of the reference paper which were identified using the [3.6] versus [3.6] - [5.8] color-magnitude diagram, since contamination removal methods could not be utilized for these objects, (ii) the 24 candidate variable YSOs listed in Table 6 of the reference paper, nor (iii) 21 of the 29 candidate O-star cluster members which were listed in table 7 of the reference paper. This table was created by the HEASARC in January 2012 based on an electronic version of Tables 3 and 4 from the reference paper which were obtained from the ApJ web site. This is a service provided by NASA HEASARC .

CASSINI ORBITER SATURN UVIS STELLAR RING OCC 2004-2017

This data set contains derived radial occultation profiles of the rings of Saturn based on stellar occultation observations made with the Cassini UVIS instrument between October 2004 and August 2017.

CASSINI SATURN UVIS SOLAR STELLAR BRIGHTNESS TIME SERIES 1.1

Photometric observations of stellar occultations by Saturnian rings, satellites, atmospheres, and Jovian atmosphere.

The ATLAS All-Sky Stellar Reference Catalog ConeSearch

All MAST catalog holdings are available via Cone Search endpoints. This service provides access to the ATLAS All-Sky Stellar Reference Catalog.The Asteroid Terrestrial-impact Last Alert System (ATLAS) observes most of the sky every night in search of dangerous asteroids. Its data are also used to search for photometric variability, where sensitivity to variability is limited by photometric accuracy. Since each exposure spans 7.6 deg corner to corner, variations in atmospheric transparency in excess of 0.01 mag are common, and 0.01 mag photometry cannot be achieved by using a constant flat field calibration image. We therefore have assembled an all-sky reference catalog of approximately one billion stars to m~19 from a variety of sources to calibrate each exposure's astrometry and photometry. Gaia DR2 is the source of astrometry for this ATLAS Refcat2. The sources of g, r, i, z photometry include Pan-STARRS DR1, the ATLAS Pathfinder photometry project, ATLAS re-flattened APASS data, SkyMapper DR1, APASS DR9, the Tycho-2 catalog, and the Yale Bright Star Catalog. We have attempted to make this catalog at least 99% complete to m less than 19, including the brightest stars in the sky. We believe that the systematic errors are no larger than 5 millimag RMS, although errors are as large as 20 millimag in small patches near the galactic plane. All available missions are listed at http://archive.stsci.edu/vo/mast_services.html.

CoRoT Stellar Targets for Exoplanet Detection Observation Log

CoRoT was a space astronomy mission devoted to the study of the variability with time of stars' brightness, with an extremely high accuracy (100 times better than from the ground), for very long durations (up to 150 days) and with a very high duty cycle (more than 90%). The mission was led by CNES in association with four French laboratories, and 7 participating countries and agencies (Austria, Belgium, Brazil, Germany, Spain, and the ESA Science Programme). The satellite is composed of a PROTEUS platform (the 3rd in the series), and a unique instrument: a stellar photometer. It was launched on December 27th, 2006 on a Soyuz Rocket, from Baikonour. The mission has lasted almost 6 years (the nominal 3 years duration and a 3 years extension) and has observed more than 160,000 stars. It suddenly stopped sending data on November 2nd, 2012. CoRoT performed Ultra High Precision Photometry of Stars to detect and characterize the variability of their luminosity with two main objectives: (i) the variability of the object itself: oscillations, rotation, magnetic activity, etc.; (ii) variability due to external causes such as bodies in orbit around the star: planets and companion stars. The original scientific objectives were focused on the study of stellar pulsations (asteroseismology) to probe the internal structure of stars, and the detection of small exoplanets through their transit in front of their host star, and the measurement of their sizes. This lead to the introduction of two modes of observations, working simultaneously: - The bright star mode dedicated to very precise seismology of a small sample (171) of bright and nearby stars (presented in the file named "Bright_star.dat" in the CDS version at <a href="https://cdsarc.cds.unistra.fr/ftp/cats/B/corot/">https://cdsarc.cds.unistra.fr/ftp/cats/B/corot/</a>): these data are not included in this HEASARC table, notice; - The faint star mode, observing a very large number of stars at the same time, to detect transits, which are rare events, as they imply the alignment of the star, the planet and the observer (these data are presented in the file named "Faint_star.dat" in the CDS version at <a href="https://cdsarc.cds.unistra.fr/ftp/cats/B/corot/">https://cdsarc.cds.unistra.fr/ftp/cats/B/corot/</a>): this HEASARC table is based on this sample. The large amount of data gathered in this mode mode turned out to be extremely fruitful for many topics of stellar physics. Due to project constraints, two regions of the sky were accessible (circles of 10 degrees centered on the equator around Right Ascensions of 06h 50m and 18h 50m). They are called the CoRoT 'eyes': the first one is called the "anticenter" eye, whereas the second one is called the "center eye". Each pointing covers 1.4 x 2.8 square degrees. The CoRoT project is still processing the data, aiming at removing instrumental artifacts and defects. Therefore the format and content of the catalog is still somewhat evolving. More details on the data can be found in the file <a href="http://idoc-corotn2-public.ias.u-psud.fr/jsp/doc/CoRoT_N2_versions_30sept2014.pdf">http://idoc-corotn2-public.ias.u-psud.fr/jsp/doc/CoRoT_N2_versions_30sept2014.pdf</a>. More details on the CoRoT N2 data may be found in the documentation file <a href="http://idoc-corotn2-public.ias.u-psud.fr/jsp/doc/DescriptionN2v1.5.pdf">http://idoc-corotn2-public.ias.u-psud.fr/jsp/doc/DescriptionN2v1.5.pdf</a>. This HEASARC table contains information on stars observed by CoRoT in its exoplanet detection program. A few percent of these stars have 2 entries since they were observed in different windows (as specified by the corot_window_id parameter) in a subsequent observing run to the initial run in which they were observed. Each entry in this table corresponds to the unique specification of target and corot_window_id, each with a link to its associated N2 data products. The original names of the parameters in this table, as given in the CoRoT mission documentation, are given in square brackets at the end of the parameter descriptions listed below. This table was created by the HEASARC in May 2012 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/B/corot">CDS Catalog B/corot</a> file Faint_star.dat. The HEASARC routinely updates this table after updates are made to the CDS version of this catalog. This is a service provided by NASA HEASARC .

Palomar-Green Catalog of UV-Excess Stellar Objects

The Palomar-Green Catalog of UV-Excess Stellar Objects provides positions (the original_ra and original_dec parameters) accurate to about 8 arcsec in each coordinate, photographic B-magnitudes accurate to 0.29 mag, spectral types, some cross-references, and photoelectric broad-band, multichannel, and Stroemgren colors when available. Of the 1874 objects in the catalog as published in 1986 (1878 in this version), 1715 comprise a statistically complete sample covering 10714 square degrees from 266 fields taken on the Palomar 18-inch Schmidt telescope. Limiting magnitudes vary from field to field, ranging from 15.49 to 16.67. The overall completeness is estimated to be 84%, but that figure and the relative contributions of magnitude, color, and accidental errors vary depending on the magnitude and color distribution of the spectroscopic subsample. The dominant population in this catalog is that of the hot, hydrogen-atmosphere subdwarfs, the sdB stars, which comprise nearly 40 per cent of the sample. The hot white dwarfs of spectral types DA, DB, and DO account for 21, 2.8, and 1.0 per cent of the sample, respectively, while cooler DC or DZ white dwarfs add another 1.2 per cent. Cataclysmic variables and composite-spectrum binaries account for 5 per cent, although many other spectra dominated by a hot star showed evidence for a cool companion at red wavelengths. Planetary nebulae central stars account for another 0.5 per cent. Extragalactic objects comprise about 9 per cent of the complete sample, with QSOs representing 5.4 per cent. Only 0.3 per cent (6 objects) remain with totally unsatisfactory or unknown spectral classes. (Notice that all of these percentage estimates are based on the published version of this catalog, and that the values in the current online version may be slightly different, as the latter includes a small number of updates and additions). In 2009, an additional data resource was added to this catalog by CDS, namely a file containing more accurate (sub-arcsecond) positions and V magnitudes (the skiff_vmag parameter), and also additional comments (the skiff_comments parameter). This new material has now been included in the HEASARC version of the PG Catalog. A full discussion of this addition can be found at <a href="http://cdsarc.u-strasbg.fr/ftp/cats/II/207A/pg_2009.txt">http://cdsarc.u-strasbg.fr/ftp/cats/II/207A/pg_2009.txt</a>. This database was initially made available at the HEASARC in June 1998 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/II/207A">CDS catalog II/207A</a> file catalog.dat which had been last updated on Oct 17 1997. In 2017, the HEASARC re-ingested this CDS catalog as it had been updated several times in the interim, notably in 2009 when an additional file (pg_pos.dat) with precise coordinates and comments provided by Brian Skiff was added. This is a service provided by NASA HEASARC .

CASSINI SATURN UVIS SOLAR STELLAR BRIGHTNESS TIME SERIES 1.0

Photometric observations of stellar occultations by Saturnian rings, satellites, atmospheres, and Jovian atmosphere.

ChaMP Extended Stellar Survey (ChESS) X-Ray Catalog

The ChaMP Extended Stellar Survey (ChESS) X-ray catalog contains 348 X-ray-emitting stars identified from correlating the Extended Chandra Multiwavelength Project (ChaMP), a wide-area serendipitous survey based on archival X-ray images, with the Sloan Digital Sky Survey (SDSS). The authors used morphological star/galaxy separation, matching to an SDSS quasar catalog, an optical color-magnitude cut, and X-ray data-quality tests to create this catalog, from a sample of 2121 matched ChaMP/SDSS sources. Their cuts retain 92% of the spectroscopically confirmed stars in the original sample while excluding 99.6% of the 684 spectroscopically confirmed extragalactic sources. Fewer than 3% of the sources in their final catalog are previously identified stellar X-ray emitters. For 42 catalog members, spectroscopic classifications are available in the literature. New spectral classifications and H-alpha measurements are presented for an additional 79 stars. The catalog is dominated by main-sequence stars; the authors estimate the fraction of giants in ChESS to be ~10%. They identify seven giant stars (including a possible Cepheid and an RR Lyrae star) as ChaMP sources, as well as three cataclysmic variables. They derive distances from ~10 to 2000 pc for the stars in the catalog using photometric parallax relations appropriate for dwarfs on the main sequence and calculate their X-ray and bolometric luminosities. These stars lie in a unique space in the LX-distance plane, filling the gap between the nearby stars identified as counterparts to sources in the ROSAT All Sky Survey and the more distant stars detected in deep Chandra and XMM-Newton surveys. For 36 newly identified X-ray-emitting M stars, the authors calculated LH-alpha/Lbol. The quantities LH-alpha/Lbol and LX/Lbol are linearly related below LX/Lbol ~ 3 x 10-4, while LH-alpha/Lbol appears to turn over at larger LX/Lbol values. Stars with reliable SDSS photometry have an ~0.1 mag blue excess in u-g, likely due to increased chromospheric continuum emission. Photometric metallicity estimates suggest that the sample is evenly split between the young and old disk populations of the Galaxy; the lowest activity sources belong to the old disk population, a clear signature of the decay of magnetic activity with age. This table was created by the HEASARC in January 2009 based on the electronic version of Tables 2 and 3 from the reference paper which were obtained from the ApJ web site. This is a service provided by NASA HEASARC .