Swift/UVOT Serendipitous Source Catalog, v1.1 SWUVOTSSC ivo://nasa.heasarc/swuvotssc NASA/GSFC HEASARC Yershov 2026-07-17 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source The first version of the Swift UVOT Serendipitous Source Catalog (UVOTSSC) provides positions and magnitudes, as well as errors and upper limits of confirmed sources, for observations taken from the start of operations in 2005 until October 1st of 2010. The first version of the UVOTSSC has been produced by processing the image data obtained from the Swift Ultraviolet and Optical Telescope (UVOT). The data processing was performed at the Mullard Space Science Laboratory (MSSL, University College London, U.K.) using Swift FTOOLS from NASA's High Energy Astrophysics Software package (HEASoft-6.11), with some customizing of the UVOT packages in order to get more complete source detection and to properly apply quality flags to those sources that were detected within the UVOT image artifacts. The total number of observations with 17'x17' images used for version 1 of the catalog is 23,059, giving 6,200,016 sources in total, of which 2,027,265 have multiple entries in the source table because they have been detected in more than one observation. Some sources were only observed in one filter. The total number of entries in the source table is 13,860,568. The S/N ratio for all sources exceeds 5 in at least one UVOT filter, the rest of the filters having a S/N greater than 3. U, B, V, UVW2, UVM2 and UVW1 refer to the filter bandpasses defined in the UVOT Filterwheel section of the MSSL documentation at <a href="http://www.mssl.ucl.ac.uk/www_astro/uvot/uvot_instrument/filterwheel/filterwheel.html">http://www.mssl.ucl.ac.uk/www_astro/uvot/uvot_instrument/filterwheel/filterwheel.html</a>. The initially released version of the catalog (2015) was done with the source identifier "SWIFTUVOT" for each source, and was made available in that form. The decision was subsequently made to rename the catalog sources by including the catalog version number. In addition, in a few instances multiple source IDs shared the same name (IAUNAME). They will be distinguished by having a letter a,b,c,.. appended to their name. Sources brighter than 0.96 counts per frame have not been included because their coincidence loss is too large to correct for. This HEASARC table contains version 1.1 of the Swift UVOT source table and contains 13,860,568 entries for the individual detections of 6,200,016 sources. The HEASARC has changed the names of many of the parameters from those given in the original table. In such cases, we have listed the original names in parentheses at the end of the parameter descriptions given below. There is a second related table which gives a summary of the observations from which the UVOTSSC sources listed in this table have been detected and measured, which is available at the HEASARC as the SWUVOTSSOB table. This table was created by the HEASARC in May 2017 based upon the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/II/339">CDS Catalog II/339</a> file uvotssc1.dat. This is a service provided by NASA HEASARC . 2014styd.confE..37P https://heasarc.gsfc.nasa.gov/W3Browse/all/swuvotssc.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=swuvotssc& GET text/xml 180 99999 true 0.00016 8.371681 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=swuvotssc GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_swuvotssc&Action=More+Options&Action=Parameter+Search&ConeAdd=1 SWIFT 0.0166666666666667 Optical UV public swuvotssc Swift/UVOT Serendipitous Source Catalog, v1.1 obsid Unique Swift Observation Identification meta.id;obs char nullable source_number Unique Source Number (SRCNUM) meta.id;src int nullable name Source Designation (UVOTSSC1 JHHMMSS.s+DDMMSSa) (IAUNAME) meta.id;meta.main char nullable ra Right Ascension degree pos.eq.ra;meta.main double nullable ra_error Right Ascension Error (RA_ERR) arcsec stat.error;pos.eq.ra;meta.main double nullable dec Declination degree pos.eq.dec;meta.main double nullable dec_error Declination Error (DEC_ERR) arcsec stat.error;pos.eq.dec;meta.main double nullable vmag UVOT/V Vega Magnitude (V_VEGAMAG) mag phot.mag;em.opt.V double nullable vmag_error Error in V Magnitude (V_MAG_ERR) mag stat.error;phot.mag;em.opt.V double nullable uvm2_mag UVOT/UVM2 Vega Magnitude (UVM2_VEGAMAG) mag phot.mag;em.UV.200-300nm double nullable uvm2_mag_error Error in UVM2 Magnitude (UVM2_MAG_ERR) mag stat.error;phot.mag;em.UV.200-300nm double nullable "__x_ra_dec" System unit vector column double nullable "__y_ra_dec" System unit vector column double nullable "__z_ra_dec" System unit vector column double nullable "__row" System index column char nullable uvm2_quality_flags Quality Flags in UVM2 (UVM2_QUALITY_FLAG) meta.code.qual;em.UV.200-300nm short nullable uvw2_ab_mag UVOT/UVW2 AB Magnitude (UVW2_ABMAG) mag phot.mag;em.UV.200-300nm double nullable v_nn_offset Distance to Closest V Source (V_SRCDIST) arcsec pos.angDistance double nullable v_major_axis Major Axis in V (V_MAJOR) arcsec phys.angSize.smajAxis;em.opt.V double nullable uvm2_minor_axis Minor Axis in UVM2 (UVM2_MINOR) arcsec phys.angSize.sminAxis;em.UV.200-300nm double nullable uvw1_quality_flags Quality Flags in UVW1 (UVW1_QUALITY_FLAG) meta.code.qual;em.UV.200-300nm short nullable v_position_angle Position Angle of Major Axis in V (V_POSANG) degree pos.posAng;em.opt.V double nullable u_position_angle Position Angle of Major Axis in U (U_POSANG) degree pos.posAng;em.opt.U double nullable v_minor_axis Minor Axis in V (V_MINOR) arcsec phys.angSize.sminAxis;em.opt.V double nullable b_extended_flag Extended Flag in UVW2 (B_EXTENDED) meta.code;phys.angSize;em.opt.B short nullable uvm2_flux_error Error in UVM2 Flux (UVM2_FLUX_ERR) erg/cm^2/s/Angstrom stat.error;phot.flux.density;em.UV.200-300nm double nullable b_flux UVOT/B Flux (B_FLUX) erg/cm^2/s/Angstrom phot.flux.density;em.opt.B double nullable uvw2_extended_flag Extended Flag in UVW2 (UVW2_EXTENDED) meta.code;phys.angSize;em.UV.200-300nm short nullable uvw1_mag_error Error in UVW2 Magnitude (UVW1_MAG_ERR) mag stat.error;phot.mag;em.UV.200-300nm double nullable uvw1_position_angle Position Angle of Major Axis in UVW1 (UVW1_POSANG) degree pos.posAng;em.UV.200-300nm double nullable b_flux_error Error in B Flux (B_FLUX_ERR) erg/cm^2/s/Angstrom stat.error;phot.flux.density;em.opt.B double nullable uvm2_nn_offset Distance to Closest UVM2 Source (UVM2_SRCDIST) arcsec pos.angDistance double nullable num_individual_obs Number of Individual Observations (N_OBSID) meta.number short nullable uvw1_flux UVOT/UVW1 Flux (UVW1_FLUX) erg/cm^2/s/Angstrom phot.flux.density;em.UV.200-300nm double nullable v_ab_mag UVOT/V AB Magnitude (V_ABMAG) mag phot.mag;em.opt.V double nullable b_quality_flags Quality Flags in B (B_QUALITY_FLAG) meta.code.qual;em.opt.B short nullable b_nn_offset Distance to Closest B Source (B_SRCDIST) arcsec pos.angDistance double nullable v_quality_flags Quality Flags in V (V_QUALITY_FLAG) meta.code.qual;em.opt.V short nullable uvw2_mag UVOT/UVW2 Vega Magnitude (UVW2_VEGAMAG) mag phot.mag;em.UV.200-300nm double nullable vmag_significance Significance (S/N) in V (V_SIGNIF) stat.likelihood;phot;em.opt.V double nullable u_flux UVOT/U Flux (U_FLUX) erg/cm^2/s/Angstrom phot.flux.density;em.opt.U double nullable b_position_angle Position Angle of Major Axis in B (B_POSANG) degree pos.posAng;em.opt.B double nullable uvw2_mag_error Error in UVW2 Magnitude (UVW2_MAG_ERR) mag stat.error;phot.mag;em.UV.200-300nm double nullable uvm2_ab_mag UVOT/UVM2 AB Magnitude (UVM2_ABMAG) mag phot.mag;em.UV.200-300nm double nullable uvw1_ab_mag UVOT/UVW1 AB Magnitude (UVW1_ABMAG) mag phot.mag;em.UV.200-300nm double nullable u_ab_mag UVOT/U AB Magnitude (U_ABMAG) mag phot.mag;em.opt.U double nullable uvw1_nn_offset Distance to Closest UVW1 Source (UVW1_SRCDIST) arcsec pos.angDistance double nullable bmag_error Error in B Magnitude (B_MAG_ERR) mag stat.error;phot.mag;em.opt.B double nullable bmag UVOT/N Vega Magnitude (B_VEGAMAG) mag phot.mag;em.opt.B double nullable u_minor_axis Minor Axis in U (U_MINOR) arcsec phys.angSize.sminAxis;em.opt.U double nullable uvm2_major_axis Major Axis in UVM2 (UVM2_MAJOR) arcsec phys.angSize.smajAxis;em.UV.200-300nm double nullable uvm2_mag_significance Significance (S/N) in UVM2 (UVM2_SIGNIF) stat.likelihood;phot;em.UV.200-300nm double nullable uvw1_mag_significance Significance (S/N) in UVW1 (UVW1_SIGNIF) stat.likelihood;phot;em.UV.200-300nm double nullable umag_significance Significance (S/N) in U (U_SIGNIF) stat.likelihood;phot;em.opt.U double nullable u_quality_flags Quality Flags in U (U_QUALITY_FLAG) meta.code.qual;em.opt.U short nullable uvw1_extended_flag Extended Flag in UVW2 (UVW1_EXTENDED) meta.code;phys.angSize;em.UV.200-300nm short nullable b_minor_axis Minor Axis in B (B_MINOR) arcsec phys.angSize.sminAxis;em.opt.B double nullable entry_number Sequential Identification Number for Each Entry in Catalog meta.id int nullable uvw1_flux_error Error in UVW1 Flux (UVW1_FLUX_ERR) erg/cm^2/s/Angstrom stat.error;phot.flux.density;em.UV.200-300nm double nullable u_flux_error Error in U Flux (U_FLUX_ERR) erg/cm^2/s/Angstrom stat.error;phot.flux.density;em.opt.U double nullable uvw2_mag_significance Significance (S/N) in UVW2 (UVW2_SIGNIF) stat.likelihood;phot;em.UV.200-300nm double nullable uvw1_mag UVOT/UVW1 Vega Magnitude (UVW1_VEGAMAG) mag phot.mag;em.UV.200-300nm double nullable uvw2_position_angle Position Angle of Major Axis in UVW2 (UVW2_POSANG) degree pos.posAng;em.UV.200-300nm double nullable uvw2_major_axis Major Axis in UVW2 (UVW2_MAJOR) arcsec phys.angSize.smajAxis;em.UV.200-300nm double nullable bii Galactic Latitude degree pos.galactic.lat double nullable obs_sum_number Reference Number in the Observation Table (N_SUMMARY) meta.code int nullable u_nn_offset Distance to Closest U Source (U_SRCDIST) arcsec pos.angDistance double nullable lii Galactic Longitude degree pos.galactic.lon double nullable uvm2_position_angle Position Angle of Major Axis in UVM2 (UVM2_POSANG) degree pos.posAng;em.UV.200-300nm double nullable umag UVOT/U Vega Magnitude (U_VEGAMAG) mag phot.mag;em.opt.U double nullable uvw1_major_axis Major Axis in UVW1 (UVW1_MAJOR) arcsec phys.angSize.smajAxis;em.UV.200-300nm double nullable uvw2_flux UVOT/UVW2 Flux (UVW2_FLUX) erg/cm^2/s/Angstrom phot.flux.density;em.UV.200-300nm double nullable b_ab_mag UVOT/B AB Magnitude (B_ABMAG) mag phot.mag;em.opt.B double nullable b_major_axis Major Axis in B (B_MAJOR) arcsec phys.angSize.smajAxis;em.opt.B double nullable num_filters Number of Filters Included in this Observation (NFILT) meta.number short nullable v_flux UVOT/V Flux (V_FLUX) erg/cm^2/s/Angstrom phot.flux.density;em.opt.V double nullable u_extended_flag Extended Flag in UVW2 (U_EXTENDED) meta.code;phys.angSize;em.opt.U short nullable umag_error Error in U Magnitude (U_MAG_ERR) mag stat.error;phot.mag;em.opt.U double nullable uvm2_flux UVOT/UVM2 Flux (UVM2_FLUX) erg/cm^2/s/Angstrom phot.flux.density;em.UV.200-300nm double nullable v_flux_error Error in V Flux (V_FLUX_ERR) erg/cm^2/s/Angstrom stat.error;phot.flux.density;em.opt.V double nullable uvw1_minor_axis Minor Axis in UVW1 (UVW1_MINOR) arcsec phys.angSize.sminAxis;em.UV.200-300nm double nullable bmag_significance Significance (S/N) in B (B_SIGNIF) stat.likelihood;phot;em.opt.B double nullable uvw2_quality_flags Quality Flags in UVW2 (UVW2_QUALITY_FLAG) meta.code.qual;em.UV.200-300nm short nullable u_major_axis Major Axis in U (U_MAJOR) arcsec phys.angSize.smajAxis;em.opt.U double nullable uvw2_flux_error Error in UVW2 Flux (UVW2_FLUX_ERR) erg/cm^2/s/Angstrom stat.error;phot.flux.density;em.UV.200-300nm double nullable uvm2_extended_flag Extended Flag in UVW2 (UVM2_EXTENDED) meta.code;phys.angSize;em.UV.200-300nm short nullable uvw2_minor_axis Minor Axis in UVW2 (UVW2_MINOR) arcsec phys.angSize.sminAxis;em.UV.200-300nm double nullable uvw2_nn_offset Distance to Closest UVW2 Source (UVW2_SRCDIST) arcsec pos.angDistance;em.UV.200-300nm double nullable v_extended_flag Extended Flag in UVW2 (V_EXTENDED) meta.code;phys.angSize;em.opt.V short nullable