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"

19549 results found.

  1. GRB 200115A: Mondy optical afterglow candidate
  2. LIGO/Virgo S200112r : No significant candidates in TAROT - FRAM - GRANDMA observations.
  3. LIGO/Virgo S200115j: No neutrino candidates at Pierre Auger Observatory
  4. LIGO/Virgo S200114f: Swift-XRT sources and observations
  5. LIGO/Virgo S200115j: no counterpart candidate in SVOM/GWAC observations
  6. Baksan Neutrino Observatory Alert 200116.21: Global MASTER-Net observations report
  7. LIGO/Virgo S200115j: no counterpart candidates in the Swift/BAT observations
  8. IPN triangulation of GRB 200111A
  9. LIGO/Virgo S200115j: No counterpart candidates in Fermi-LAT observations
  10. GRB 200115A: Nanshan-0.6m optical upper limit
  11. LIGO/Virgo S200115j : no neutrino counterpart candidate in ANTARES search
  12. LIGO/Virgo S200115j: No counterpart candidates in HAWC observations
  13. GRB 200114A: DDOTI/OAN optical observations report
  14. LIGO/Virgo S200114f: No Counterparts in DDOTI/OAN Optical Observations
  15. LIGO/Virgo S200114f: no counterpart candidates in the Swift/BAT observations
  16. LIGO/Virgo S200114f: No counterpart candidates in Fermi-LAT observations
  17. LIGO/Virgo S200114f: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  18. LIGO/Virgo S200114f : no neutrino counterpart candidate in ANTARES search
  19. LIGO/Virgo S200114f: No counterpart candidates in HAWC observations
  20. Fermi-LAT Gamma-ray Observations of IceCube-200109A and detection of a possible new gamma-ray source, Fermi J1055.8+1034
  21. LIGO/Virgo 200112r: No counterpart candidates in Fermi-LAT observations
  22. LIGO/Virgo S200112r: Coverage and upper limits from MAXI/GSC observations
  23. LIGO/Virgo S200112r: No counterpart candidates in HAWC observations
  24. LIGO/Virgo S200112r : no neutrino counterpart candidate in ANTARES search
  25. IceCube 200109A: No significant detection in HAWC
  26. Fermi-LAT ANTARES coincidence: No significant detection in HAWC
  27. IceCube-200109A: Swift-XRT and UVoT Follow-up Observations
  28. ANTARES 200108A: No detection by Swift-XRT
  29. GRB 200107B: Swift/UVOT Observations
  30. GRB 200109A: Swift/UVOT Upper Limits
  31. LIGO/Virgo S200105ae : No significant candidates in TAROT - FRAM - GRANDMA observations.
  32. Fermi-LAT ANTARES coincidence: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  33. GRB 200109A: Enhanced Swift-XRT position
  34. Swift GRB200109.07: Global MASTER-Net observations report
  35. GRB 200109A: Swift detection of a burst
  36. Fermi-LAT ANTARES coincidence
  37. Fermi-LAT Gamma-ray Observations of IceCube-200107A
  38. IceCube-200107A: No significant detection in HAWC
  39. IceCube-200107A: No candidates from the Zwicky Transient Facility
  40. IceCube-200107A: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  41. GRB 200107B: Swift detection of a burst
  42. LIGO/Virgo 200105ae: No counterpart candidates in Fermi-LAT observations
  43. LIGO/Virgo S200105ae: No counterpart candidates in HAWC observations
  44. LIGO/Virgo S200105ae: no counterpart candidates in the Swift/BAT observations
  45. LIGO/Virgo S200105ae: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  46. LIGO/Virgo S200105ae : no neutrino counterpart candidate in ANTARES search
  47. Fermi-LAT Gamma-ray Observations of IceCube-191231A
  48. IceCube-191231A: No significant detection in HAWC
  49. IceCube-191231A: No counterpart candidates in INTEGRAL SPI-ACS and IBIS prompt observation
  50. GRB 191228A: Mondy optical upper limit
  51. IPN triangulation of GRB 191227B (short)
  52. GRB 191228A: Swift/UVOT Upper Limits
  53. GRB 191228A: Enhanced Swift-XRT position
  54. GRB 191228A: UKIRT NIR upper limit
  55. GRB 191228A: Swift detection of a burst
  56. GRB 191227A: Marginal detection by Fermi-LAT
  57. GRB 191227A: MITSuME Akeno optical upper limits
  58. Swift Trigger 946234 is probably not a GRB
  59. LIGO/Virgo S191205ah: MASTER OT detection
  60. LIGO/Virgo S191222n : No significant candidates in FRAM-TAROT-GRANDMA observations
  61. GRB 191221B: Swift/UVOT Detection
  62. LIGO/Virgo S191222n: no counterpart candidate in SVOM/GWAC observations
  63. GRB 191221B: iTelescope T17 detection
  64. LIGO/Virgo S191216ap: No significant candidates found in Pan-STARRS observations
  65. GRB 191221B: Zadko observatory - Gingin optical observations
  66. GRB 191221B: Swift-XRT refined Analysis
  67. LIGO/Virgo S191213g : No significant candidates found in GRANDMA citizen science observations
  68. LIGO/Virgo S191222n: no counterpart candidates in the Swift/BAT observations
  69. LIGO/Virgo S191222n: No counterpart candidates in Fermi-LAT observations
  70. GRB 191221B: MASTER VWFC OT yearly detection
  71. GRB 191221B: Correction to GCN26551 - VIRT OT observation
  72. GRB 191221B: VIRT Optical Upper Limits
  73. LIGO/Virgo S191222n : no neutrino counterpart candidate in ANTARES search
  74. LIGO/Virgo S191222n: Coverage and upper limits from MAXI/GSC observations
  75. LIGO/Virgo S191222n: No counterpart candidates in HAWC observations
  76. GRB 191221B: Enhanced Swift-XRT position
  77. GRB 191221B: Swift detection of a burst and a very bright optical candidate
  78. LIGO/Virgo S191216ap: VLA/JAGWAR radio monitoring of the 1-sigma HAWC region
  79. LIGO/Virgo S191216ap: No radio candidates so far in the VLA/JAGWAR galaxy targeted search
  80. GRB 191220A: Swift/UVOT Upper Limits
  81. GRB 191220A: AbAO optical observations
  82. GRB 191220A: Enhanced Swift-XRT position
  83. GRB 191220A: SAO RAS possible OT detection
  84. GRB 191220A: Swift detection of a burst
  85. LIGO/Virgo S191213g: Palomar 60-inch imaging of AT2019wxt
  86. LIGO/Virgo S191216ap: No candidates found in J-GEM follow-up observations of HAWC error region
  87. LIGO/Virgo S191213g: No counterpart candidate in the NOWT observations
  88. LIGO/Virgo S191213g: No candidates found in J-GEM follow-up observations
  89. LIGO/Virgo S191216ap: IceCube event: MASTER OF detection in GW and Neutrino error field
  90. LIGO/Virgo S191216ap: No significant counterpart candidates in SAGUARO observations
  91. LIGO/Virgo S191215w : No significant candidates in TAROT - FRAM - GRANDMA observations.
  92. LIGO/Virgo G191216ap: No counterpart candidates in Fermi-LAT observations
  93. LIGO/Virgo S191216ap: no counterpart candidates in the Swift/BAT observations
  94. Fermi-LAT Gamma-ray Observations of IceCube-191215A
  95. LIGO/Virgo S191216ap : no neutrino counterpart candidate in ANTARES search
  96. LIGO/Virgo S191216ap: No counterpart candidates in HAWC observations
  97. LIGO/Virgo S191215w: no counterpart candidates in the Swift/BAT observations
  98. LIGO/Virgo S191215w: No counterpart candidates in Fermi-LAT observations
  99. LIGO/Virgo S191215w: No counterpart candidates in HAWC observations
  100. LIGO/Virgo S191215w: Coverage and upper limits from MAXI/GSC 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