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"

3117 results found.

  1. Fermi GRB 200402C: Global MASTER-Net observations report
  2. Fermi GRB 200401A: Global MASTER-Net observations report
  3. GRB 200325B: Mondy continued observations
  4. Fermi trigger No 606918292: Global MASTER-Net observations report
  5. GRB 200326A: Fermi GBM Final Real-time Localization
  6. Fermi trigger No 606681997: Global MASTER-Net observations report
  7. LIGO/Virgo S200316bj: no counterpart candidate in SVOM/GWAC-F30 observations
  8. Fermi trigger No 606263732: Global MASTER-Net observations report
  9. LIGO/Virgo S200316bj : No significant candidates in TAROT - FRAM - GRANDMA observations.
  10. LIGO/Virgo S200316bj: Upper limits from Insight-HXMT/HE observations
  11. LIGO/Virgo S200316bj: no counterpart candidate in SVOM/GWAC observations
  12. LIGO/Virgo S200316bj: No Counterparts in DDOTI/OAN Optical Observations
  13. LIGO/Virgo S200316bj: no counterpart candidates in the Swift/BAT observations
  14. SGR Swift J1818.0-1607: BOOTES-4/MET optical limit
  15. Fermi trigger No 605756501: Global MASTER-Net observations report
  16. Swift-BAT trigger 960986: Swift detection of a new SGR Swift J1818.0-1607
  17. Fermi trigger No 605632577: Global MASTER-Net observations report
  18. GRB 200310A: MAXI/GSC detection
  19. LIGO/Virgo S200302c : No significant candidates in FRAM - TAROT - GRANDMA observations.
  20. GRB 200303A: Fermi GBM Final Real-time Localization
  21. LIGO/Virgo S200302c: No counterpart candidates in KAIT observations
  22. LIGO/Virgo S200302c: no counterpart candidates in the Swift/BAT observations
  23. LIGO/Virgo S200224ca: Transient found in Swift/UVOT counterpart search
  24. LIGO/Virgo S200225q : No significant candidates in TAROT - FRAM - GRANDMA observations.
  25. LIGO/Virgo S200213t: No significant EM counterparts identified from continued GECKO observation of host galaxy candidates
  26. GRB 200227A: Mondy optical upper limit
  27. LIGO/Virgo S200224ca : No significant candidates in TAROT - FRAM - GRANDMA observations
  28. LIGO/Virgo S200224car: GRAWITA VST-ESO PARANAL observations.
  29. LIGO/Virgo S200225q: no counterpart candidates in the Swift/BAT observations
  30. LIGO/Virgo S200224ca: no counterpart candidates in the Swift/BAT observations
  31. GRB 200224B: DDOTI/OAN optical observations report
  32. LIGO/Virgo S200224ca: No counterpart candidates in KAIT observations
  33. LIGO/Virgo S200224ca: GRAWITA-Campo Imperatore observations.
  34. Fermi trigger No 604231129: Global MASTER-Net observations report
  35. GRB 200224C: Fermi GBM Final Real-time Localization
  36. GRB 200223A: Fermi GBM Final Real-time Localization
  37. LIGO/Virgo S200219ac: no counterpart candidate in SVOM/GWAC-F30 observations
  38. LIGO/Virgo S200219ac : No significant candidates in TAROT - FRAM - GRANDMA observations.
  39. LIGO/Virgo S200219ac: No counterpart candidates in KAIT observations
  40. LIGO/Virgo S200219ac: no counterpart candidates in the Swift/BAT observations
  41. GRB 200216B: Mondy and AbAO optical upper limits
  42. LIGO/Virgo S200213t: No EM counterparts found from continued GECKO observation of host galaxy candidates
  43. LIGO/Virgo S200213t : No significant candidates in FRAM - OAJ - TAROT - GRANDMA observations
  44. LIGO/Virgo S200213t: No notable candidates in GOTO imaging
  45. LIGO/Virgo S200213t: One additional candidate from the Zwicky Transient Facility
  46. LIGO/Virgo S200213t: More Candidates from the Zwicky Transient Facility
  47. LIGO/Virgo S200213t: No counterpart candidates in KAIT observations
  48. LIGO/Virgo S200208q : No significant candidates in TAROT - FRAM - GRANDMA observations
  49. LIGO/Virgo S200208q: no counterpart candidate in SVOM/C-GFT observations
  50. LIGO/Virgo S200213t: Candidates from the Zwicky Transient Facility
  51. LIGO/Virgo trigger S200213t: Possible host galaxies
  52. GRB 200131A: Tautenburg observations
  53. LIGO/Virgo S200208q: No counterpart candidates in KAIT observations
  54. LIGO/Virgo S200208q: No counterpart candidates in Fermi-LAT observations
  55. LIGO/Virgo S200208q: no counterpart candidates in the Swift/BAT observations
  56. Fermi trigger No 602817262: Global MASTER-Net observations report
  57. GRB 200205B: Swift-BAT refined analysis
  58. Fermi trigger No 602731380: Global MASTER-Net observations report
  59. Fermi trigger No 602626648: Global MASTER-Net observations report
  60. GRB 200205C: Fermi GBM Final Real-time Localization
  61. ZTF20aajnksq: Occulted by Earth at the time of GRB 200128A
  62. ZTF Discovery of ZTF20aajnksq: a Rapidly Fading Luminous Transient in the GRB 200128A Localiziation Region
  63. LIGO/Virgo S200128d: no counterpart candidate in SVOM/GWAC observations
  64. LIGO/Virgo S200128d : No significant candidates in FRAM - TAROT - GRANDMA observations
  65. Fermi trigger No 602071201: Global MASTER-Net observations report
  66. Fermi trigger No 602056641: Global MASTER-Net observations report
  67. LIGO/Virgo S200129m: no counterpart candidates in the Swift/BAT observations
  68. LIGO/Virgo S200128d: No counterpart candidates in KAIT observations
  69. LIGO/Virgo S200128d: no counterpart candidates in the Swift/BAT observations
  70. GRB 200125B: DDOTI/OAN optical observations report
  71. Fermi trigger No 601841483: Global MASTER-Net observations report
  72. Fermi trigger No 601729856: Global MASTER-Net observations report
  73. Fermi trigger No 601677816: Global MASTER-Net observations report
  74. LIGO/Virgo S200114f : No significant candidates in TAROT - FRAM - GRANDMA observations
  75. GRB 200122A: MITSuME Akeno optical upper limits
  76. Fermi trigger No 601363105: Global MASTER-Net observations report
  77. Konus-Wind observation of GRB 200120A
  78. Fermi trigger No 601254300: Global MASTER-Net observations report
  79. IceCube Alert 200120.78: Global MASTER-Net observations report
  80. LIGO/Virgo S200115j : No significant candidates in TAROT - FRAM - GRANDMA observations
  81. IceCube-200117A: One Additional Candidate Counterpart from the Zwicky Transient Facility
  82. IceCube-200117A: Candidate Counterpart from the Zwicky Transient Facility
  83. LIGO/Virgo S200105ae: More candidates from the Zwicky Transient Facility
  84. LIGO/Virgo S200114f: More candidates from the Zwicky Transient Facility
  85. LIGO/Virgo S200112r : No significant candidates in TAROT - FRAM - GRANDMA observations.
  86. LIGO/Virgo S200115j: no counterpart candidate in SVOM/GWAC observations
  87. LIGO/Virgo S200115j: no counterpart candidates in the Swift/BAT observations
  88. LIGO/Virgo S200115j: Candidates from the Zwicky Transient Facility
  89. LIGO/Virgo trigger S200115j: Possible host galaxies
  90. LIGO/Virgo S200114f: no counterpart candidates in the Swift/BAT observations
  91. IceCube-200109A: Candidate Counterparts from the Zwicky Transient Facility
  92. LIGO/Virgo S200114f: Candidates from the Zwicky Transient Facility
  93. LIGO/Virgo S200114f: Coverage and upper limits from MAXI/GSC observations
  94. LIGO/Virgo S200105ae : No significant candidates in TAROT - FRAM - GRANDMA observations.
  95. Fermi trigger No 600227156: Global MASTER-Net observations report
  96. Swift GRB200109.07: Global MASTER-Net observations report
  97. GRB 200109A: Swift detection of a burst
  98. LIGO/Virgo S200105ae: Candidates from the Zwicky Transient Facility
  99. GRB 200107B: Fermi GBM observation
  100. IceCube-200107A: No candidates from the Zwicky Transient Facility

Advanced

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