- ID:
- ivo://nasa.heasarc/ulxrbcat
- Title:
- Ultraluminous X-Ray Sources in External Galaxies Catalog
- Short Name:
- ULXRB
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table is a catalog of ultraluminous X-ray sources (ULXs) in external galaxies, where ULXs have been defined as compact, off-nuclear X-ray sources with X-ray luminosities in the range of 10<sup>39</sup> - 10<sup>41</sup> erg/s. The aim of this catalog is to provide easy access to the properties of ULXs, their possible counterparts at other wavelengths (optical, IR, and radio), and the properties of their host galaxies. The catalog contains 229 ULXs found in 85 galaxies which had been reported in the astronomy literature as of April 2004. Most ULXs are stellar-mass-black hole X-ray binaries, but it cannot be excluded that some ULXs might be intermediate-mass black holes. A small fraction of the candidate ULXs might be background Active Galactic Nuclei (AGN) or Supernova Remnants (SNRs). ULXs with luminosity above 10<sup>40</sup> erg/s are found in both starburst galaxies and in the halos of early-type galaxies. Some notes on individual galaxies and/or ULXs in this catalog can be found in the file <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/429/1125/notes.dat">https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/429/1125/notes.dat</a> which is available at the CDS. This table was created by the HEASARC in January 2005, based on CDS tables J/A+A/429/1125/table1a.dat and table1b.dat. It was updated in September 2012 to correct an error in the declination signs of the NGC 253 objects. This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/flarestars
- Title:
- UVCet-typeFlareStars&RelatedObjectsCatalog
- Short Name:
- FlareStars
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the catalog of the UV Cet-type flare stars and related objects in the solar vicinity. This new catalog of flare stars includes 463 objects. It contains astrometric, spectral and photometric data as well as information on the infrared, radio and X-ray properties and general stellar parameters. This table was created by the HEASARC in October 2005 based on the merger of 3 CDS tables (table1.dat, table2.dat and atble3.dat) from the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+AS/139/555/">CDS Catalog J/A+AS/139/555/</a> . This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/uvotbscat
- Title:
- UVOT Bright Star Catalog
- Short Name:
- UVOTBSCAT
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This catalog was compiled from 4 catalogs: Tycho-2, GVCS III, NGC, and the Yale Bright Star Catalog. All catalogs were preprocessed before compiling this catalog to achieve uniform columns and units. Next, they were merged into one catalogue before eliminating "red" objects and precessing all coordinates to epoch 2000.0. The catalog was then corrected for missing decimal points. Finally, the catalog was sorted by R.A. for ease of locating objects within the catalogue. The original catalog contained 239,853 objects brighter than 12.0 mags. This table was originally created by the HEASARC in July 2008 based on an input table supplied by the Swift Project which was compiled by Elizabeth Auden at MSSL. It was renamed to UVOTBSCAT in January 2009. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/vlagbsoph
- Title:
- VLA Goulds Belt Survey Ophiuchus Complex Source Catalog
- Short Name:
- VLAGBSOPH
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains results from large-scale (~2000 arcmin<sup>2</sup>), deep (~20 µJy), high-resolution (~1") radio observations of the Ophiuchus star-forming complex obtained with the Karl G. Jansky Very Large Array (JVLA) at wavelengths of 4 and 6 cm (frequencies of 7.5 and 4.5 GHz). In total, 189 sources were detected, 56 of them associated with known young stellar objects (YSOs), and 4 with known extragalactic objects; the other 129 remain unclassified, but most of them are most probably background quasars. The vast majority of the young stars detected at radio wavelengths have spectral types K or M, although four objects of A/F/B types and two brown dwarf candidates are also detected. At least half of these young stars are non-thermal (gyrosynchrotron) sources, with active coronae characterized by high levels of variability, negative spectral indices, and (in some cases) significant circular polarization. As expected, there is a clear tendency for the fraction of non-thermal sources to increase from the younger (Class 0/I or flat spectrum) to the more evolved (Class III or weak-line T Tauri) stars. The young stars detected both in X-rays and at radio wavelengths broadly follow a Gudel-Benz relation, but with a different normalization than the most radio-active types of stars. Finally, the authors detected a ~70 mJy compact extragalactic source near the center of the Ophiuchus core, which should be used as gain calibrator for any future radio observations of this region. The observations were obtained with the JVLA of the National Radio Astronomy Observatory (NRAO). Two frequency sub-bands, each 1-GHz wide, and centered at 4.5 and 7.5 GHz, respectively, were recorded simultaneously. The observations were obtained on three different epochs (2011 February 17/19, April 3/4, and May 4/6) typically separated from one another by a month. The angular resolution of the observations is of the order of 1 arcsecond. To identify sources in their observations, the authors used the images corresponding to the concatenation of the three epochs, which provided the highest sensitivity. The criteria used to consider a detection as firm were: (1) sources with reported counterparts and a flux larger than four times the rms noise of the area, or (2) sources with a flux larger than five times the rms noise of the area and without reported counterparts. The authors searched the literature for previous radio detections, and for counterparts at X-ray, optical, near-infrared, and mid-infrared wavelengths. The search was done in SIMBAD, and accessed all the major catalogs (listed explicitly in the footnote of Table 3 in the reference paper). Note that the Spitzer c2d catalog includes cross-references to other major catalogs which were taken into account in their counterpart search. The authors considered a radio source associated with a counterpart at another wavelengths if the separation between the two was below the combined uncertainties of the two data sets. This was about 1.5 arcseconds for the optical and infrared catalogs, but could be significantly larger for some of the radio catalogs (for instance, the NVSS has a positional uncertainty of about 5 arcseconds). The authors found that only 76 of the sources detected here had previously been reported at radio wavelengths (matches are listed in the radio_name parameter in such cases), while the other 113 are new radio detections. On the other hand, they found a total of 100 counterparts at other wavelengths. Note that there are a significant number of sources that were previously known at radio wavelengths and have known counterparts at other frequencies. As a consequence, the number of sources that were previously known (at any frequency) is 134, while 55 of the sources in this sample are reported here for the first time. The authors argue that most of these 55 objects are likely background sources. They note, however, that 18 of the 129 unclassified objects (55 identified here for the first time and 74 previously known at radio wavelengths) are compact, have a positive spectral index, or exhibit high variability. Since these latter two properties are not expected of quasars (which are certainly variable, but usually not strongly on such short timescale), but would be natural characteristics of young stars, the authors argue that a small population of YSOs might be present among the unclassified sources. This population could account for, at most, 15% of the unclassified sources, and possibly significantly less. This table was created by the HEASARC in July 2015 based on electronic versions of Tables 1, 3 and 5 from the reference paper, which were obtained from the CDS (Catalog J/ApJ/775/63 files table1.dat, table3.dat and table5.dat). This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/vlagbsori
- Title:
- VLA Goulds Belt Survey Orion Complex Source Catalog
- Short Name:
- VLAGBSORI
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains results from a high-sensitivity (60 µJy), large-scale (2.26 deg<sup>2</sup>) survey obtained with the Karl G. Jansky Very Large Array (JVLA) as part of the Gould's Belt Survey (GBS) program. The authors detected 374 and 354 sources at 4.5 and 7.5 GHz, respectively. Of these, 148 are associated with previously known young stellar objects (YSOs). Another 86 sources previously unclassified at either optical or infrared wavelengths exhibit radio properties that are consistent with those of young stars. The overall properties of these sources at radio wavelengths such as their variability and radio to X-ray luminosity relation are consistent with previous results from the GBS. These detections provide target lists for follow-up Very Long Baseline Array radio observations to determine their distances, as YSOs are located in regions of high nebulosity and extinction, making it difficult to measure their optical parallaxes. The observations were obtained with the JVLA of the National Radio Astronomy Observatory (NRAO) in its A configuration. The observations of the 210 fields in the Orion Molecular Clouds A and B were obtained in three different epochs (2011 June 25 to July 4, July 23 to 30, and August 25 to 29, as described in Table 1 of the reference paper) typically separated from one another by a month. The 210 individual fields have been split into 7 maps, with 30 fields being observed per map, as follows: 12 in the lambda Ori region, 3 in L1622, 27 are shared between NGC 2068 and NGC 2071, 14 are shared between NGC 2023 and NGC 2024, 11 in the sigma Ori region, 109 in the Orion Nebula Cluster (ONC), 16 in L1641-N, 8 in L1641-C, and 10 in L1641-S (see Figures 1 to 7 in the reference paper). Two frequency sub-bands, each 1-GHz wide, and centered at 4.5 and 7.5 GHz, respectively, were recorded simultaneously. The authors achieved a nearly uniform rms noise of 60 µJy beam<sup>-1</sup> at both frequencies in all the regions. The only exception to this is in the Trapezium region due to nebular emission; there the noise was 200 µJy beam<sup>-1</sup> after excluding baselines smaller than 150 kilo-lambda during imaging to remove extended emission. Sources were identified through a visual inspection of the individual fields at 4.5 GHz during the cleaning and imaging process since an automated source identification was deemed to be not sufficiently advanced and produced results that were too unreliable. In particularly clustered regions such as the Trapezium and NGC 2024, in addition to standard imaging, data from all three epochs were combined into a single image for source identification purposes only to improve statistical significance of each detection. The authors detected a combined total of 374 sources among the three epochs for all of the regions. All sources but one had fluxes greater than five times the rms noise in at least one epoch. The remaining source, 'GBS-VLA J053518.67-052033.1', was detected at two epochs with maximum detection probability of 4.9 sigma in a single epoch data. It is found in the Trapezium region, and has known counterparts in other wavelength regimes. The authors cross-referenced their catalog of sources with previous major radio, infrared, optical and X-ray surveys of the regions published in the literature. They have generally considered sources in these surveys to be counterparts if they had positional coincidences less than 1 arcsecond, but have allowed for larger offsets if the combined uncertainty between the databases was large. Of 374 detected sources, 261 have been previously found at another wavelength region, while 113 are new detections. 146 sources have been detected in X-rays, 94 at optical wavelengths, 218 at infrared, and 63 in previous radio surveys. Of the previously identified sources, 1 is extragalactic, while the other 148 as young stellar objects (YSOs). Of the YSOs, 106 have been placed on the standard class system based on the IRAC color-color classification of Allen et al. (2004, ApJS, 154, 363). There are 11 Class 0/I, 26 Class II, and 70 Class III type stars. A total of 225 sources are either new detections or, to the authors' knowledge, have not been previously classified in the literature. Of these remaining objects, they have identified 86 as exhibiting variability or high levels of circular polarization. While the authors cannot exclude the possibility that any of them are extragalactic in nature, quasars are not expected to vary as strongly on timescales of few weeks to few months, and exhibit very weak circular polarization, so these sources (listed in Table 5 of the reference paper) are likely YSO candidates. Using the same criteria of variability and circular polarization would identify only 107 of the 148 previously-known YSOs; thus we cannot tell which of the remaining 139 unidentified sources are YSOs or extragalactic objects. This table was created by the HEASARC in July 2015 based on electronic versions of Tables 2 and 4 from the reference paper, which were obtained from the ApJ web site. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/vlagbsser
- Title:
- VLA Goulds Belt Survey Serpens Region Source Catalog
- Short Name:
- VLAGBSSER
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains results from a deep (~17 µJy) radio continuum observations of the Serpens molecular cloud, the Serpens south cluster, and the W40 region that were obtained using the Jansky Very Large Array (JVLA) in its A configuration. The authors detected a total of 146 sources, 29 of which are young stellar objects (YSOs), 2 of which are BV stars, and 5 more of which are associated with phenomena related to YSOs. Based on their radio variability and spectral index, the authors propose that about 16 of the remaining 110 unclassified sources are also YSOs. For approximately 65% of the known YSOs detected here as radio sources, the emission is most likely non-thermal and related to stellar coronal activity. As also recently observed in Ophiuchus, this sample of YSOs with X-ray counterparts lies below the fiducial Guedel & Benz (1993, ApJ, 405, L63) relation. In the reference paper, the authors analyze the proper motions of nine sources in the W40 region, thus allowing them to better constrain the membership of the radio sources in the region. The Serpens molecular cloud and the Serpens South cluster were observed in the same observing sessions on three different epochs (2011 June 17, July 19, and September 12 UT), using 25 and 4 pointings, respectively, with the JVLA at 4.5 and 4.5GHz. The W40 region, on the other hand, was only observed on two epochs (2011 June 17 and July 16), using 13 pointings. The details of the observations are listed in Table 1 of the reference paper. The authors adopted the same criteria as Dzib et al. (2013, ApJ, 775, 63) to consider a detection as firm. For new sources, i.e., those without reported counterparts in the literature, they considered 5-sigma detections, where sigma is the rms noise of the area around the source. For known sources with counterparts in the literature, on the other hand, they included 4-sigma detections. According to these criteria, they detected 94 sources in the Serpens molecular cloud, 41 in the W40 region, and 8 in the Serpens South cluster, for a total of 143 detections. Out of the 143 sources, 69 are new detections (see Section 3.2 of the reference paper). GBS-VLA source positions were compared with source positions from X-ray, optical, near-IR, mid-IR, and radio catalogs. GBS-VLA sources were considered to have a counterpart at another wavelength when the positional coincidences were better than the combined uncertainties of the two data sets. These were about 1 arcsecond for the IR catalogs. For the X-ray and radio catalogs it depended on the instrument and its configuration. The search was done in SIMBAD and included all the major catalogs. The authors also accessed the lists with all YSOs in the c2d-GB clouds compiled by Dunham et al.(2013, AJ, 145, 94) and L.E. Allen et al. (2015, in preparation). In total, 354 c2d-GB sources lie inside the regions observed by the present survey. In order to find their radio counterparts, the authors imaged regions of 64 pixels in each dimension, centered in the c2d-GB positions, and combining accordingly with each region, the three or two epochs. For this search, they only used the field whose phase center was closest to the source. Three additional radio sources were found in Serpens South in this pursuit, increasing the number of the radio detections to 146. This table was created by the HEASARC in October 2015 based on electronic versions of Tables 2, 3 and 6 from the reference paper, which were obtained from the CDS (Catalog J/ApJ/805/9 files table2.dat, table3.dat and table6.dat). This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/vlagbstau
- Title:
- VLA Goulds Belt Survey Taurus-Auriga Complex Source Catalog
- Short Name:
- VLAGBSTAU
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains results from a multi-epoch radio study of the Taurus-Auriga complex made with the Karl G. Jansky Very Large Array (JVLA) at frequencies of 4.5 GHz and 7.5 GHz. A total of 610 sources were detected, 59 of which are related to young stellar objects (YSOs) and 18 to field stars. The properties of 56% of the young stars are compatible with non-thermal radio emission. The authors also show that the radio emission of more evolved YSOs tends to be more non-thermal in origin and, in general, that their radio properties are compatible with those found in other star-forming regions. By comparing their results with previously reported X-ray observations, the authors noticed that YSOs in Taurus-Auriga follow a Guedel-Benz relation with a scaling factor, kappa, of 0.03, as they previously suggested for other regions of star formation. In general, YSOs in Taurus-Auriga and in all the previous studied regions seem to follow this relation with a dispersion of ~1 dex. Finally, the authors propose that most of the remaining sources are related with extragalactic objects but provide a list of 46 unidentified radio sources whose radio properties are compatible with a YSO nature (identified in this implementation of their catalog by values for the parameter radio_yso_flag of 'Y'). The observations were obtained with the JVLA of the National Radio Astronomy Observatory (NRAO) in its B and BnA configuration. Two frequency sub-bands, each 1 GHz wide, and centered at 4.5 and 7.5 GHz, respectively, were recorded simultaneously. The observations were obtained in three different time periods (February 25/26/28 to March 6, April 12/17/20/25, and April 30 to May 1/5/14/22, all in 2011) typically separated from one another by a month: see Table 1 of the reference paper for more details. For their study, the authors observed 127 different target fields distributed across the cloud complex (Figure 1 of the reference paper). The fields were chosen to cover previously known YSOs. In 33 of those fields, the authors could observe more than one YSO target, while in the remaining 94 fields, only one YSO was targeted. In most cases, the infrared evolutionary class (i.e., Classes I, II, or III) or T Tauri evolutionary status (classical or weak line) of the targeted sources was known from the literature. The final images covered circular areas of 8.8 and 14.3 arcminutes in diameter, for the 7.5 and 4.5 GHz sub-bands, respectively, and were corrected for the effects of the position-dependent primary beam response. The noise levels reached for each individual observation was about ~40 µJy and ~30 µJy, at 4.5 GHz and7.5 GHz, respectively. The visibilities of the three, or two, observations obtained for each field were concatenated to produce a new image with a lower noise level (of about ~25 µJy at 4.5 GHz and ~18 µJy at 7.5 GHz). The angular resolution of ~1 arcsecond (see the synthesized beam sizes in Table 1 of the reference paper) allows an uncertainty in position of ~0.1 arcseconds or better. In the observed area, there are a total of 196 known YSOs.The first step was the identification of radio sources in the observed fields. The authors follow the procedure and criteria presented by Dzib et al. (2013, ApJ, 775, 63) who consider a detection as firm if the sources have a flux larger than 4 times the noise level and there is a counterpart known at another wavelength, else they require a flux which is 5 times the noise level. The identification was done using the images corresponding to the concatenation of the observed epochs, which provides the highest sensitivity. From this, a total of 609 sources were detected. Of these sources, 215 were only detected in the 4.5 GHz sub-band, while six were only detected in the 7.5 GHz sub-band. The remaining 388 sources were detected in both sub-bands. The authors searched the literature for previous radio detections, and for counterparts at X-ray, optical, near-infrared, and mid-infrared wavelengths. The search was done using SIMBAD, and accessed all the major catalogs. They considered a radio source to be associated with a counterpart at another wavelength if the separation between the two was below the combined uncertainties of the two data sets. This was about 1.0 arcsecond for the optical and infrared catalogs, but could be significantly larger for some of the radio catalogs (for instance, the NVSS has a positional uncertainty of about 5 arcseconds). They found that only 120 of the sources detected here had previously been reported at radio wavelengths, while the other 491 are new radio detections. On the other hand, the authors found a total of 270 counterparts at other wavelengths. In the literature, 18 are classified as field stars, 49 as extragalactic, 1 is classified as either a star or an extragalactic source in different surveys, 49 are classified as YSOs, 11 are classified as either YSO and extragalactic, and the remaining 143 sources are unclassified. Note that 56 sources were previously known at radio wavelengths but do not have known counterparts at other frequencies. As a consequence, the number of sources that were previously known (at any frequency) is 327, while 284 of the sources in this sample are reported here for the first time. This table was created by the HEASARC in July 2015 based on electronic versions of Tables 1, 4 and 5 from the reference paper, which were obtained from the ApJ web site. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/wackerling
- Title:
- Wackerling Catalog of Early-Type Emission-Line Stars
- Short Name:
- Wackerling
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Wackerling Catalog contains entries for 5326 early-type emission-line stars. Of these stars, 1424 have no spectral classification but are assumed to be of early type. Some 71 percent of the stars in this catalog can also be found in the Mount Wilson and the Mount Wilson-Michigan survey catalogs. The Wackerling Catalog contains numerous cross identifications to other designations (common name, HD, DM, LS, MWC, TON, HIL, WRA, HEN, etc.), rough spectroscopic types, magnitudes (visual and blue), and positions. The version of the Wackerling Catalog on which the HEASARC database is based was obtained from the ADC and differs in some respects from the original published version, notice. This online catalog was originally ingested by the HEASARC in July 1999, based on a machine-readable table obtained from the ADC/CDS data centers. It was updated in May 2020 to reflect updates to the spect_type_code values made by the CDS for improved database compatibility. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/wds
- Title:
- Washington Double Star Catalog
- Short Name:
- WDS
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Washington Double Star Catalog (WDS), maintained by the United States Naval Observatory (USNO), is the world's principal database of astrometric double and multiple star information. The WDS Catalog contains positions, discoverer designations, epochs, position angles, separations, magnitudes, spectral types, proper motions and when available, Durchmusterung numbers and notes for the components of close to 100,000 systems based on ~600,000 means. The current version at the HEASARC is updated weekly and is derived from the version available online at <a href="https://crf.usno.navy.mil/wds/">https://crf.usno.navy.mil/wds/</a> (and mirrored at <a href="http://www.astro.gsu.edu/wds/">http://www.astro.gsu.edu/wds/</a>), the latter being potentially updated nightly. The Washington Visual Double Star Catalog (WDS) is the successor to the Index Catalogue of Visual Double Stars, 1961.0 (IDS; Jeffers & van den Bos, 1963). Three earlier double star catalogs in the 20th century, those by Burnham (BDS; 1906), Innes (SDS; 1927), and Aitken (ADS; 1932), each covered only a portion of the sky. Both the IDS and the WDS cover the entire sky, and the WDS is intended to contain all known visual double stars for which at least one differential measure has been published. The WDS is continually updated as published data become available. Prior to this, two major updates have been published (Worley & Douglass 1984, 1997). The Washington Double Star Catalog (WDS) has seen numerous changes since the last major release of the catalog. The application of many techniques and considerable industry over the past few years has yielded unprecedented gains in both the number of systems and the number of measures. This version of the WDS catalog was first created at the HEASARC in March 2002 based on the USNO online version (available at either <a href="https://crf.usno.navy.mil/wds/">https://crf.usno.navy.mil/wds/</a> or <a href="http://www.astro.gsu.edu/wds/">http://www.astro.gsu.edu/wds/</a>), and is updated by the HEASARC on at least a weekly basis. The table schema was last revised in February 2005. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/woodebcat
- Title:
- Wood Interacting Binaries Catalog
- Short Name:
- Wood/Bin
- Date:
- 07 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This catalog, also called the Finding List (FL) of Interacting Binaries (5th edition), was abstracted from the Card Catalog maintained at the University of Florida which contains information on all published, and to the extent available, unpublished work on eclipsing binaries. The Card Catalog originated with Raymond Smith Dugan in the 1930's, who published from it the first edition of "A Finding List for Observers of Eclipsing Variables" (Dugan 1934, Princeton Univ. Obs. Contrib. No. 15). Successive editions of FL were subsequently published by Pierce (1947, Princeton Univ. Obs. Contrib. No. 22), by Wood (1953, Univ. Pennsylvania Astron. Series, Vol. VIII), by Koch et al. (1963, Univ. Pennsylvania Astron. Series, Vol. IX), and by Wood et al. (1980, Univ. Pennsylvania Astron. Series, Vol. XII). The FL was conceived as an aid to observers of eclipsing variables in selecting an observing program efficiently from the collection of all known data in an easy-to-use format. Although this format has changed over the years to meet existing requirements, the basic information content remains the same. The current edition differs from previous ones in the extension of the magnitude limit at minimum light from 13 to 15. In earlier editions, a binary system was not included unless the editors were reasonably certain that the system was indeed an eclipsing or (rarely) an ellipsoidal variable. The fifth edition includes all systems that the editors were fairly certain are either eclipsing or radiometrically variable binaries. The catalog fields are Finding List number; star name; position (given in the original catalog in equinox 1900); blue magnitude at maximum light; bandpass of maximum light; depth of primary minimum in same bandpass; bandpass primary minimum; depth of secondary minimum and its bandpass; spectral class of star eclipsed at primary light and optional uncertainty character; spectral class of star eclipsed at secondary light; most recent reliable epoch of primary minimum; most recent orbital period; duration of primary minimum; duration of totality of primary minimum; BD, CoD, CPD, and HD number; alternate designations of system; and codes indicating the nature of the system. This database was created by the HEASARC in December 1997 based on a computer readable version of the catalog that was obtained from the CDS (their catalog VI/44): a few additions were made by the HEASARC that are listed in the HEASARC_Changes section of the present document. This is a service provided by NASA HEASARC .
