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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"

11528 results found.

  1. Fermi trigger No 596808579: Global MASTER-Net observations report
  2. Fermi GBM trigger 596808579/191130507 is not a GRB
  3. GRB 191129A: AstroSat CZTI detection
  4. LIGO/Virgo S191129u: No counterpart candidates in Fermi-LAT observations
  5. LIGO/Virgo S191129u: not observable by Fermi-GBM
  6. Fermi trigger No 596690552: Global MASTER-Net observations report
  7. GRB 191129A: Fermi GBM Final Real-time Localization
  8. GRB 191125B: MASTER-VWFC synchronous observation
  9. IceCube-191122A: Not observable by Fermi-GBM
  10. Fermi trigger No 596387570: Global MASTER-Net observations report
  11. GRB 191125B: Fermi GBM Final Real-time Localization
  12. GRB 191125A: Fermi GBM Final Real-time Localization
  13. Fermi-LAT Gamma-ray Observations of IceCube-191122A
  14. GRB 191118A: Insight-HXMT/HE detection
  15. IceCube-191122A - IceCube observation of a high-energy neutrino candidate event
  16. GRB 191119A: AstroSat CZTI detection of a short GRB
  17. Fermi-LAT Gamma-ray Observations of IceCube-191119A
  18. IceCube-191119A: Upper limits from Fermi-GBM Observations
  19. IceCube-191119A - IceCube observation of a high-energy neutrino candidate event
  20. GRB 191118A: BALROG localization (Fermi Trigger 595807926 / GRB 191118925)
  21. GRB 191118A: Fermi GBM Final Real-time Localization
  22. GRB 191117B: Fermi GBM Final Real-time Localization
  23. GRB 191117A: Fermi GBM Final Real-time Localization
  24. GRB 191111A: Insight-HXMT/HE detection
  25. GRB 191027A: CALET Gamma-Ray Burst Monitor detection
  26. Announcing the GW Treasure Map
  27. LIGO/Virgo S191110af: Potential pulsar counterparts
  28. GRB 191113A: Fermi GBM Final Real-time Localization
  29. GRB 191031D: CALET Gamma-Ray Burst Monitor detection
  30. GRB 191112A: Fermi GBM Final Real-time Localization
  31. GRB 191111B: BALROG localization (Fermi Trigger 595170435 / GRB 191111547)
  32. GRB 191111B: Fermi GBM Final Real-time Localization
  33. LIGO/Virgo S191110af: No counterpart candidates in Fermi-LAT observations
  34. GRB 191111A: Fermi GBM Final Real-time Localization
  35. LIGO/Virgo S191110af: Upper limits from Fermi-GBM Observations
  36. LIGO/Virgo S191109d: No counterpart candidates in Fermi-LAT observations
  37. GRB 191110A: Fermi GBM Final Real-time Localization
  38. LIGO/Virgo S191109d: Upper limits from Fermi-GBM Observations
  39. GRB 191108A: Fermi GBM Final Real-time Localization
  40. LIGO/Virgo S191105e: No counterpart candidates in Fermi-LAT observations
  41. LIGO/Virgo S191105e: Upper limits from Fermi-GBM Observations
  42. GRB 191031D: Chandra upper limit
  43. Fermi trigger No 594592184: Global MASTER-Net observations report
  44. Fermi trigger No 594523229: Global MASTER-Net observations report
  45. Fermi GBM GRB 191104C (trigger 594592184 / 191104854) is not a GRB
  46. GRB 191104C: Fermi GBM Final Real-time Localization
  47. Fermi GBM GRBs 191104 A, B, C and triggers 594534420/191104185 and 594563923/191104527 are not GRBs
  48. Fermi trigger No 594563923: Global MASTER-Net observations report
  49. GRB 191104B/GRB 191104C are SGR 1935+2154
  50. Fermi trigger No 594557071: Global MASTER-Net observations report
  51. GRB 191104C: BALROG localization (Fermi Trigger 594557071 / GRB 191104448)
  52. GRB 191104C: Fermi GBM Final Real-time Localization
  53. Fermi trigger No 594551878: Global MASTER-Net observations report
  54. Fermi trigger No 594528816: Global MASTER-Net observations report
  55. GRB 191104B: Fermi GBM Final Real-time Localization
  56. Fermi GBM triggers 594523229/191104056 and 594528816/191104120 are not GRBs
  57. GRB 191104A: Fermi GBM Final Real-time Localization
  58. GRB 191031D: Zwicky Transient Facility Follow-Up of a Swift Short GRB (Trigger 594249816/191031891)
  59. GRB 191031D: Gemini optical upper limit
  60. GRB 191031C: Insight-HXMT/HE detection
  61. Fermi trigger No 594336535: Global MASTER-Net observations report
  62. Fermi trigger No 594227699: Global MASTER-Net observations report
  63. GRB 191101B: Fermi GBM Final Real-time Localization
  64. GRB 191031D: MMT Binospec Optical Upper Limit
  65. GRB 191031D: AstroSat CZTI detection
  66. Konus-Wind observation of GRB 191031D
  67. GRB 191031D: MITSuME Akeno optical upper limits
  68. GRB 191031D: AGILE/MCAL observations
  69. GRB 191031D: COATLI Optical Observations
  70. GRB 191031D: RATIR Optical and NIR Observations
  71. GRB 191031D: VLA 9.8 GHz upper limit
  72. GRB 191031C: Fermi GBM detection
  73. GRB 191031D: Fermi GBM detection
  74. GRB 191031A: Fermi GBM detection
  75. Correction in name: GRB 191031D (not GRB 191031C)
  76. GRB 191031D: Swift detection of a short hard burst
  77. GRB 191031C: Fermi GBM Final Real-time Localization
  78. GRB 191031C: Fermi GBM Final Real-time Localization
  79. Fermi trigger No 594175000: Global MASTER-Net observations report
  80. GRB 191031B: Fermi GBM Final Real-time Localization
  81. GRB 191031A: COATLI Optical Observations
  82. GRB 191031A: Fermi GBM Final Real-time Localization
  83. Konus-Wind observation of GRB 191027A
  84. Correction to GCN 26079 regarding GRB 191027A
  85. GRB 191028B: MASTER optical observation
  86. IPN triangulation of GRB 191027A
  87. GRB 191028B: BALROG localization (Fermi Trigger 593964489 / GRB 191028589)
  88. GRB 191028B: Fermi GBM Final Real-time Localization
  89. Fermi GBM trigger 593931926/191028212 is not a GRB
  90. GRB 191028A: Fermi GBM Final Real-time Localization
  91. GRB 191027A: BALROG localization (Fermi Trigger 593882352 / GRB 191027638)
  92. GRB 191027A: Fermi GBM Final Real-time Localization
  93. GRB 191026A: Fermi GBM Final Real-time Localization
  94. GRB 191023A: MASTER optical observation
  95. GRB 191023A: BALROG localization (Fermi Trigger 593536021 / GRB 191023630)
  96. GRB 191023A: Fermi GBM Final Real-time Localization
  97. GRB 191019B: AstroSat CZTI detection
  98. GRB 191022B: Fermi GBM Final Real-time Localization
  99. GRB 191022A: BALROG localization (Fermi Trigger 593419810 / GRB 191022285)
  100. GRB 191022A: Fermi GBM Final Real-time Localization

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