SMMGRS ivo://nasa.heasarc/smmgrs NASA/GSFC HEASARC SMM Project; HEASARC 2026-06-12 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov GRB Solar Flare The Gamma-Ray Spectrometer (GRS) was one of two instruments on the Solar Maximum Mission (SMM) which independently monitored cosmic gamma-ray bursts from SMM's launch in February 1980 until the end of the mission in 1989. The GRS was designed for investigation of the gamma-ray spectrum of solar flares (Forrest, D.J. et al. 1980, Sol. Phys., 65, 15). The main detector was an array of seven gain-controlled 7.6 cm diameter X 7.6 cm thick NaI(Tl) detectors. A complete spectrum was obtained every 16.38 seconds in the energy range 0.3-9 MeV. The number of counts in three energy windows covering the 4.2-6.4 MeV range was read out every 2.048 seconds. In addition, the number of counts in an approximately 50 keV wide window near 300 keV was read out every 64 milliseconds. The spectrometer was shielded by a 2.5 cm thick CsI(Na) annulus and a 25 cm diameter X 7.6 cm thick CsI(Na) back detector. The shield elements defined a field of view of approximately 135 degrees (FWHM) in the solar direction. The CsI back detector and the seven NaI detectors together provided a high-energy spectrometer with approximately 100 cm<sup>2</sup> effective area and four energy channels from 10 to 100 MeV. The number of counts in those high-energy channels was read out every 2.048 seconds. The experiment was complemented by two 8 cm<sup>2</sup> X 0.6 cm thick NaI(Tl) detectors which measured the X-ray portion of the spectrum every 1.024 seconds in the range from 13 keV to 182 keV. This database table was created by the HEASARC in the early 1990s based on tables supplied by the SMM Project and was subsequently revised in February 2002. This is a service provided by NASA HEASARC . https://heasarc.gsfc.nasa.gov/W3Browse/all/smmgrs.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=smmgrs GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_smmgrs&Action=More+Options&Action=Parameter+Search&ConeAdd=1 GAMMA-RAY BURSTS 0.0166666666666667 Gamma-ray public smmgrs GRS Gamma-Ray Bursts name Burst Designation meta.id;meta.main char nullable "time" Date and Time of Gamma-Ray Burst mjd time.start;obs double nullable fluence Total Burst Fluence (10^-6 erg/cm^2) 10^-6_erg/cm^2 double nullable fluence_error Uncertainty in Burst Fluence (10^-6 erg/cm^2) 10^-6_erg/cm^2 double nullable duration Duration of Burst (seconds) s time.duration;obs short nullable vvmax Ratio of Volume to Maximal Volume (V/Vmax) double nullable "__row" System index column char nullable dec_smm Apparent Declination (J2000) of the SMM Spacecraft from Center of Earth char nullable ra_smm Apparent Right Ascension (J2000) of the SMM Spacecraft from Center of Earth char nullable earth_angle Angle from Center of Earth to Sun (as seen from SMM) degree short nullable saa_flag Flag Indicates Spacecraft near SAA char nullable confirmation Burst Confirmations by Other Experiments char nullable id_method_flag Flag Indicates Burst Found by Computer char nullable seconds Universal Time of Burst Onset (Seconds Since Midnight UT of Burst Date) s int nullable