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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"

11099 results found.

  1. GRB 191112A: Fermi GBM Final Real-time Localization
  2. GRB 191111B: BALROG localization (Fermi Trigger 595170435 / GRB 191111547)
  3. GRB 191111B: Fermi GBM Final Real-time Localization
  4. LIGO/Virgo S191110af: No counterpart candidates in Fermi-LAT observations
  5. GRB 191111A: Fermi GBM Final Real-time Localization
  6. LIGO/Virgo S191110af: Upper limits from Fermi-GBM Observations
  7. LIGO/Virgo S191109d: No counterpart candidates in Fermi-LAT observations
  8. GRB 191110A: Fermi GBM Final Real-time Localization
  9. LIGO/Virgo S191109d: Upper limits from Fermi-GBM Observations
  10. GRB 191108A: Fermi GBM Final Real-time Localization
  11. LIGO/Virgo S191105e: No counterpart candidates in Fermi-LAT observations
  12. LIGO/Virgo S191105e: Upper limits from Fermi-GBM Observations
  13. GRB 191031D: Chandra upper limit
  14. Fermi trigger No 594592184: Global MASTER-Net observations report
  15. Fermi trigger No 594523229: Global MASTER-Net observations report
  16. Fermi GBM GRB 191104C (trigger 594592184 / 191104854) is not a GRB
  17. GRB 191104C: Fermi GBM Final Real-time Localization
  18. Fermi GBM GRBs 191104 A, B, C and triggers 594534420/191104185 and 594563923/191104527 are not GRBs
  19. Fermi trigger No 594563923: Global MASTER-Net observations report
  20. GRB 191104B/GRB 191104C are SGR 1935+2154
  21. Fermi trigger No 594557071: Global MASTER-Net observations report
  22. GRB 191104C: BALROG localization (Fermi Trigger 594557071 / GRB 191104448)
  23. GRB 191104C: Fermi GBM Final Real-time Localization
  24. Fermi trigger No 594551878: Global MASTER-Net observations report
  25. Fermi trigger No 594528816: Global MASTER-Net observations report
  26. GRB 191104B: Fermi GBM Final Real-time Localization
  27. Fermi GBM triggers 594523229/191104056 and 594528816/191104120 are not GRBs
  28. GRB 191104A: Fermi GBM Final Real-time Localization
  29. GRB 191031D: Zwicky Transient Facility Follow-Up of a Swift Short GRB (Trigger 594249816/191031891)
  30. GRB 191031D: Gemini optical upper limit
  31. GRB 191031C: Insight-HXMT/HE detection
  32. Fermi trigger No 594336535: Global MASTER-Net observations report
  33. Fermi trigger No 594227699: Global MASTER-Net observations report
  34. GRB 191101B: Fermi GBM Final Real-time Localization
  35. GRB 191031D: MMT Binospec Optical Upper Limit
  36. GRB 191031D: AstroSat CZTI detection
  37. Konus-Wind observation of GRB 191031D
  38. GRB 191031D: MITSuME Akeno optical upper limits
  39. GRB 191031D: AGILE/MCAL observations
  40. GRB 191031D: COATLI Optical Observations
  41. GRB 191031D: RATIR Optical and NIR Observations
  42. GRB 191031D: VLA 9.8 GHz upper limit
  43. GRB 191031C: Fermi GBM detection
  44. GRB 191031D: Fermi GBM detection
  45. GRB 191031A: Fermi GBM detection
  46. Correction in name: GRB 191031D (not GRB 191031C)
  47. GRB 191031D: Swift detection of a short hard burst
  48. GRB 191031C: Fermi GBM Final Real-time Localization
  49. GRB 191031C: Fermi GBM Final Real-time Localization
  50. Fermi trigger No 594175000: Global MASTER-Net observations report
  51. GRB 191031B: Fermi GBM Final Real-time Localization
  52. GRB 191031A: COATLI Optical Observations
  53. GRB 191031A: Fermi GBM Final Real-time Localization
  54. Konus-Wind observation of GRB 191027A
  55. Correction to GCN 26079 regarding GRB 191027A
  56. GRB 191028B: MASTER optical observation
  57. IPN triangulation of GRB 191027A
  58. GRB 191028B: BALROG localization (Fermi Trigger 593964489 / GRB 191028589)
  59. GRB 191028B: Fermi GBM Final Real-time Localization
  60. Fermi GBM trigger 593931926/191028212 is not a GRB
  61. GRB 191028A: Fermi GBM Final Real-time Localization
  62. GRB 191027A: BALROG localization (Fermi Trigger 593882352 / GRB 191027638)
  63. GRB 191027A: Fermi GBM Final Real-time Localization
  64. GRB 191026A: Fermi GBM Final Real-time Localization
  65. GRB 191023A: MASTER optical observation
  66. GRB 191023A: BALROG localization (Fermi Trigger 593536021 / GRB 191023630)
  67. GRB 191023A: Fermi GBM Final Real-time Localization
  68. GRB 191019B: AstroSat CZTI detection
  69. GRB 191022B: Fermi GBM Final Real-time Localization
  70. GRB 191022A: BALROG localization (Fermi Trigger 593419810 / GRB 191022285)
  71. GRB 191022A: Fermi GBM Final Real-time Localization
  72. GRB 191019B: Fermi GBM Final Real-time Localization
  73. Fermi trigger No 593176520: Global MASTER-Net observations report
  74. FACT follow-up of ANTARES-Fermi 191011A
  75. Fermi trigger No 593045905: Global MASTER-Net observations report
  76. GRB 191017C: Fermi GBM Final Real-time Localization
  77. GRB 191017A: Fermi GBM Final Localization
  78. 191017A: BALROG localization (Fermi Trigger 592997024 / GRB 191017391)
  79. Fermi trigger No 592818648: Global MASTER-Net observations report
  80. ANTARES 191011A: AMON + ANTARES Identification of a High-Energy Neutrino + Fermi LAT Coincidence
  81. GRB 191009A: AstroSat CZTI detection
  82. GRB 191011A: Swift/UVOT Detection
  83. GRB 191011A: Fermi GBM observation
  84. GRB 19011A: Optical Afterglow Detection with LCO
  85. GRB 191009A: Insight-HXMT/HE detection
  86. GRB 191011A: BALROG localization (Fermi Trigger 592461363 / GRB 191011192)
  87. GRB 191011A: VLT X-shooter redshift from RRM Observations
  88. GRB 191011A: Fermi GBM Final Real-time Localization
  89. GRB 191009A: BALROG localization (Fermi Trigger 592297741 / GRB 191009298)
  90. GRB 191009A: Fermi GBM Final Real-time Localization
  91. Fermi trigger No 592211224: Global MASTER-Net observations report
  92. Fermi trigger No 592211224: Global MASTER-Net observations report
  93. GRB 191008A: Fermi GBM Final Real-time Localization
  94. Fermi/GBM observation of a bright burst from magnetar SGR 1935+2154
  95. GRB 191001A: Swift-XRT observations
  96. GRB 191001A: Fermi GBM observation
  97. GRB 190919A: AstroSat CZTI detection
  98. Fermi-LAT Gamma-ray Observations of IceCube-191001A
  99. IceCube-191001A: Not observable by Fermi-GBM
  100. IPN triangulation of GRB 191001A

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