The CNS3 catalog contains all known stars as of 1991 that are within 25 parsecs of the Sun. It depends mainly on a preliminary version (Spring 1989) of the new General Catalogue of Trigonometric Parallaxes (YPC) prepared by Dr. William F. van Altena (Yale University). The catalog contains every then-known star with a trigonometric parallax greater than or equal to 0.0390 arcsec, even though it may be evident from photometry or for other reasons that the star has a larger distance. For red dwarf stars, new color-magnitude calibrations for broad-band colors were carried out and applied. For white dwarfs, the recipes of McCook and Sion in ApJS, 65, 603 (1987) were applied. Stroemgren photometry was used (not yet systematically) for early-type stars and for late dwarfs, the latter supplied by E. H. Olsen from Copenhagen Observatory (private communication). In contrast to the CNS2 (Gliese 1969) catalog, trigonometric parallaxes and photometric or spectroscopic parallaxes were not combined in this version. The resulting parallax in the present version is the trigonometric parallax if the relative error of the trigonometric parallax is smaller than 14 percent. The parallax may be the photometric or spectroscopic parallax only if no trigonometric parallax is available or if the standard error of the trigonometric parallax is considerably larger. The original catalog and the notes describing it were prepared by Wilhelm Gliese and Hartmut Jahreiss, Astronomisches Rechen-Institut, Moenchhofstrasse 12-14, D-6900 Heidelberg 1, Germany, in 1991. The CDS has made a number of formatting and documentation changes in the period 1994-1997, e.g., in December 1997 it added a running number to the name for 1388 stars which had all been given the same name of "NN" in the original version, starting with "NN 3001" (for the first "NN" star in order of 1950 RA), and ending with "NN 4388" (for the last "NN" star in order of 1950 RA). This revised version of the catalog (CDS/ADC Catalog V/70A) was used by the HEASARC to create this database in February 2001. This is a service provided by NASA HEASARC .

The GSC-I catalog is an all-sky catalog of positions and magnitudes for approximately 19 million stars and other objects in the sixth to fifteenth magnitude range. The GSC is primarily based on an all-sky, single-epoch collection of Schmidt plates. For centers at +6 degrees and north, a 1982 epoch "Quick V" survey was obtained from the Palomar Observatory, while for southern fields, materials from the UK SERC J survey (epoch = 1975) and its equatorial extension (epoch = 1982) were used.

This table contains results from a total of 459 repeated 3.1-GHz radio continuum observations (of which 379 were used in a search for transient sources) of the ELAIS-N1, Coma, Lockman Hole, and NOAO Deep Wide Field Survey (NDWFS) fields as part of the Allen Telescope Array (ATA) Pi GHz Sky Survey (PiGSS). The observations were taken in 2 simultaneous 100-MHz wide bands centered at 3.04 and 3.14 GHz approximately once per day between 2009 May and 2011 April. Each image covers 11.8 square degrees and has 100" FWHM resolution. Deep images for each of the four fields have rms noise between 180 and 310 µJy (µJy), and the corresponding catalogs contain ~200 sources in each field. Typically 40-50 of these sources are detected in each single-epoch image. This represents one of the shortest cadence, largest area, multi-epoch surveys undertaken at these frequencies. The authors compared the catalogs generated from the combined images to those from individual epochs, and from monthly averages, as well as to legacy surveys. They undertook a search for transients, with particular emphasis on excluding false positive sources,but find no confirmed transients, defined here as sources that can be shown to have varied by at least a factor of 10. However, the authors found one source that brightened in a single-epoch image to at least six times the upper limit from the corresponding deep image. They also found a source associated with a z = 0.6 quasar which appears to have brightened by a factor ~3 in one of their deep images, when compared to catalogs from legacy surveys. The authors place new upper limits on the number of transients brighter than 10 mJy: fewer than 0.08 transients deg^-2 with characteristic timescales of months to years; fewer than 0.02 deg^-2 with timescales of months; and fewer than 0.009 deg^-2 with timescales of days. In this study, the authors accepted only as real sources those that are independently detected in both frequencies in at least one epoch (with a position matching tolerance of 50", corresponding to a false match probability of <2%). Their threshold of ~ 4.2 sigma for detection in a single image corresponds to a threshold of ~ 5.9 sigma in the dual-image catalog. They generated catalogs for the deep fields, consisting only of sources detected at both frequencies, and these are contained in the present HEASARC table. Notice that the authors previously published a list of 425 radio sources in the NDWFS field in the constellation of Bootes in an earlier paper (Bower et al 2010, ApJ, 725, 1792, available as the HEASARC database table PIGSSBOOFD). In the 2013 paper, they have performed a partial re-analysis of these data to conform with the updated analysis techniques used on the other three fields. This table was created by the HEASARC in March 2013 based on electronic versions of Tables 2, 3, 4 and 5 (source lists for each of the 4 fields, ELAIS N1, Lockman, Coma, and NDWFS, respectively) from the reference paper which were obtained from the ApJ web site. The HEASARC has created a new parameter called field_name which identifies in which table/field the source can be found. Thus, to select only sources in the Lockman Hole field, the user should select field_name= 'Lockman'. This is a service provided by NASA HEASARC .

The YSOVAR (Young Stellar Object VARiability) Spitzer Space Telescope observing program obtained the first extensive mid-infrared (IRAC 3.6 and 4.5 micron) time series photometry of the Orion Nebula Cluster plus smaller fields in 11 other star-forming cores (AFGL 490, NGC 1333, Mon R2, GGD 12-15, NGC 2264, L1688, Serpens Main, Serpens South, IRAS 20050+2720, IC 1396A, and Ceph C). There are ~29,000 unique objects with light curves in either or both IRAC channels in the YSOVAR data set. YSOVAR is a sister project to the Coordinated Synoptic Investigation of NGC 2264 (CSI 2264; Cody et al. 2014). Initial YSOVAR results were described in Morales-Calderon et al. (2011). Rebull et al. (2014) describes the details of target selection, data reduction, and other conventions established for this project.

The Herschel Multi-tiered Extragalactic Survey (HerMES) is a legacy programme (KPGT_soliver1) designed to map a set of nested fields totalling 380 sq. deg. Fields range in size from 0.01 to 20 sq. deg., using SPIRE at 250, 350 and 500 microns. These bands cover the peak of the redshifted thermal spectral energy distribution from interstellar dust and thus capture the reprocessed optical and ultraviolet radiation from star formation that has been absorbed by dust, and are critical for forming a complete multiwavelength understanding of galaxy formation and evolution.