Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

4055 results found.

  1. GRB 220107A: Swift/BAT-GUANO arcminute localization
  2. GRB 211229A: Swift/BAT-GUANO arcminute localization
  3. IPN triangulation of GRB 211130A
  4. GRB 211023A: optical observations and photometric evidence of supernova
  5. GRB 211107B: Swift/BAT detection
  6. GRB 211106A: Swift/BAT-GUANO candidate arcminute localization of a short burst
  7. GCN Viewer Now Available
  8. GRB 211024A: Swift/BAT-GUANO detection and candidate arcminute localization of a short burst
  9. IPN triangulation of GRB 210925B
  10. IPN triangulation of a bright burst from SGR 1935+2154
  11. GRB 210619B: Maidanak and Assy optical observations, broken power law parametrization
  12. GRB 210827A: Swift/BAT-GUANO detection and arcminute localization
  13. IPN Triangulation of a bright burst from SGR 1935+2154
  14. GRB 210706A: Swift/BAT-GUANO detection and arcminute localization
  15. GRB 210619B: Deep CAHA 2.2m detection and late-time light curve behavior
  16. GRB 210626A: Swift/BAT-GUANO detection and arcminute localization
  17. IPN triangulation of GRB 210624A (short)
  18. GRB 210622A: Swift/BAT-GUANO detection and arcminute localization of a long burst
  19. GRB 210610A: CAHA 2.2m observations and light-curve behavior
  20. GRB 210610B: University of Siena Observatory optical photometry of the afterglow
  21. GRB 210606A: Swift/BAT-GUANO detection and arcminute localization
  22. GRB 210506A: Swift/BAT-GUANO detection and possible arcminute localization of a short hard burst
  23. IPN triangulation of GRB 210424B (short/hard)
  24. GRB 210421B: Swift/BAT-GUANO detection and arcminute localization
  25. GRB 210413B: Swift/BAT detection and probable localization of a short burst
  26. GRB210410A: Joint inspection of RATIR and D50 data
  27. GRB 210323B: Swift/BAT-GUANO detection and possible arcminute localization
  28. IceCube-201221A: Upper limits from Insight-HXMT/HE observations
  29. GRB 201216A: Swift/BAT-GUANO detection and arcminute localization
  30. IceCube-201209A: Upper limits from Insight-HXMT/HE observations
  31. GRB 201128B: Swift/BAT-GUANO detection and arcminute localization
  32. GRB 201104C: Fermi GBM Final Real-time Localization
  33. GRB 201104A: Tiled Swift observations
  34. GRB 201103B: AGILE detection
  35. GRB 201104A: AGILE/MCAL detection
  36. GRB 201104A: Fermi-LAT detection
  37. GRB 201008A: Swift/BAT-GUANO detection and possible arcminute localization
  38. GRB 200809B: Swift/BAT-GUANO detection and arcminute localization
  39. GRB 200714E: Swift/BAT-GUANO detection and arcminute localization
  40. GRB 200623A: Swift/BAT-GUANO detection and arcminute localization of a short GRB
  41. LIGO/Virgo MS200618aq: Retraction of a test binary neutron star candidate
  42. LIGO/Virgo MS200619bf: Retraction of a test binary neutron star candidate
  43. LIGO/Virgo MS200618bx: Retraction of a test binary neutron star candidate
  44. LIGO/Virgo MS200618bq: Retraction of a test binary neutron star candidate
  45. LIGO/Virgo MS200614ct: Identification of a test binary black hole candidate
  46. LIGO/Virgo MS200615ce: Identification of a test binary black hole candidate
  47. LIGO/Virgo MS200614bz: Test Identification of a binary neutron star candidate
  48. LIGO/Virgo MS200615h: Retraction of a test binary neutron star candidate
  49. IPN triangulation of GRB 200415A (possible Magnetar Giant Flare in Sculptor Galaxy?)
  50. IceCube-200410A : Upper limits from Insight-HXMT/HE observations
  51. IPN Triangulation of a bright burst from SGR 1935+2154
  52. LIGO/Virgo S200225q: Swift XRT observations, 1 X-ray sources
  53. LIGO/Virgo S200224ca: Swift XRT observations, 8 X-ray sources
  54. GRB 200405B: Swift/BAT-GUANO detection and *possible* arcminute localization of a short GRB
  55. LIGO/Virgo S200316bj: Upper limits from Konus-Wind observations
  56. LIGO/Virgo S200311bg: Upper limits from Konus-Wind observations
  57. LIGO/Virgo S200302c: Upper limits from Konus-Wind observations
  58. LIGO/Virgo S200225q: Upper limits from Konus-Wind observations
  59. LIGO/Virgo S200224ca: Upper limits from Konus-Wind observations
  60. IPN triangulation of GRB 200327A (short)
  61. LIGO/Virgo S200316bj: no counterpart candidate in SVOM/GWAC-F30 observations
  62. LIGO/Virgo S200316bj: Updated Sky Localization and EM Bright Classification
  63. LIGO/Virgo S200316bj : No significant candidates in TAROT - FRAM - GRANDMA observations.
  64. LIGO/Virgo S200316bj: Upper limits from Insight-HXMT/HE observations
  65. LIGO/Virgo S200316bj: no counterpart candidate in SVOM/GWAC observations
  66. LIGO/Virgo S200316bj: Upper limits from CALET observations
  67. LIGO/Virgo S200316bj: No neutrino candidates at Pierre Auger Observatory
  68. LIGO/Virgo S200316bj: No counterpart candidates in Fermi-LAT observations
  69. LIGO/Virgo S200316bj: No Counterparts in DDOTI/OAN Optical Observations
  70. LIGO/Virgo S200316bj: no counterpart candidates in the Swift/BAT observations
  71. LIGO/Virgo S200213t: Continued Swift UVOT and XRT observations of ZTF20aamvmzj (AT2020cja)
  72. LIGO/Virgo S200316bj: No counterpart candidates in INTEGRAL SPI-ACS, and IBIS prompt observation
  73. LIGO/Virgo S200316bj: upper limits from AGILE/GRID observations
  74. LIGO/Virgo S200316bj: upper limits from AGILE/MCAL observations
  75. LIGO/Virgo S200316bj: Upper limits from Fermi-GBM Observations
  76. LIGO/Virgo S200316bj: Coverage and upper limits from MAXI/GSC observations
  77. LIGO/Virgo S200316bj : no neutrino counterpart candidate in ANTARES search
  78. LIGO/Virgo S200316bj: Upper limits from IceCube neutrino searches
  79. LIGO/Virgo S200316bj: Identification of a GW compact binary merger candidate
  80. LIGO/Virgo S200316bj: Global MASTER-Net observations report
  81. LIGO/Virgo S200311bg: Updated Sky Localization and EM Bright Classification
  82. LIGO/Virgo S200311bg: Not observable by CALET
  83. LIGO/Virgo S200311bg: Swift/BAT in the South Atlantic Anomaly
  84. LIGO/Virgo S200311bg: No significant counterpart candidates in Fermi-LAT observations
  85. LIGO/Virgo S200224ca: DESGW Summary of DECam Observations
  86. LIGO/Virgo S200311bg: not observable by Fermi GBM
  87. LIGO/Virgo S200311bg: Coverage and upper limits from MAXI/GSC observations
  88. LIGO/Virgo S200311bg: not observable by AGILE at the event time
  89. LIGO/Virgo S200311bg: No counterpart candidates in INTEGRAL SPI-ACS,prompt observation
  90. LIGO/Virgo S200311bg: Upper limits from IceCube neutrino searches
  91. LIGO/Virgo S200311bg: Identification of a GW compact binary merger candidate
  92. LIGO/Virgo S200308e: Retraction of GW compact binary merger candidate
  93. LIGO/Virgo S200302c: No notable candidates in GOTO imaging
  94. LIGO/Virgo S200302c : No significant candidates in FRAM - TAROT - GRANDMA observations.
  95. LIGO/Virgo S200225q: No notable candidates in GOTO imaging
  96. LIGO/Virgo S200302c: AstroSat CZTI upper limits
  97. LIGO/Virgo S200302c: Upper limits from Insight-HXMT/HE observations
  98. LIGO/Virgo S200303ba: Retraction of GW compact binary merger candidate
  99. LIGO/Virgo S200302c: No transient candidates in CALET observations
  100. LIGO/Virgo S200224ca: No counterpart candidates in TOROS observations

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Looking for U.S. government information and services? Visit USA.gov