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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

36352 results found.

  1. GRB 231111A: GECAM-C detection of a long burst (correction)
  2. GRB 231110A: GECAM-B detection (correction)
  3. GRB 231111A: Enhanced Swift-XRT position
  4. GRB 231111A: GECAM-C detection of a long burst
  5. GRB 231110A: GECAM detection
  6. GRB 231110A: GOTO optical upper limits
  7. GRB 231110A: SAO RAS optical observations
  8. GRB 231110A: Swift-XRT afterglow detection
  9. GRB231111A: YAHPT Observations
  10. GRB231111A: GIT confirmation of the optical afterglow
  11. GRB 231111A: MASTER OT earlier detection
  12. GRB 231111A: Nanshan/HMT optical observations
  13. GRB 231111A: Swift detection of a burst with an optical counterpart
  14. GRB231110A: WFST Observation and upper limits
  15. GRB 231110A: Swift detection of a burst
  16. GRB 231109A: Fermi GBM Final Localization
  17. Fermi GRB 231108A: Global MASTER-Net observations report
  18. GRB 231108A: Fermi GBM Final Real-time Localization
  19. GRB 231106A: AstroSat CZTI detection
  20. GRB 231106A: CALET Gamma-Ray Burst Monitor detection
  21. GRB 231104A: Swift-BAT refined analysis
  22. Fermi Gamma-ray Burst Monitor trigger 231107654 / 721064512 is not a GRB
  23. GRB 231104A: FRAM-ORM optical limit
  24. LIGO/Virgo/KAGRA S231102w: Upper limits from Swift/BAT-GUANO
  25. Fermi GRB 231106A: Global MASTER-Net observations report
  26. GRB 231104A: Wendelstein Optical/Infrared Observations
  27. GRB 231104A: NuSTAR Observation of the prompt emission
  28. GRB 231106A: Fermi GBM Final Real-time Localization
  29. GRB 231104A: 3.6m DOT optical upper limit
  30. IceCube-231103A: Upper limits from a search for additional neutrino events in IceCube
  31. GRB 231104A: NOT upper limit
  32. GRB 231104A: Fermi GBM Observation
  33. GRB 231104B: Fermi GBM Final Real-time Localization
  34. Fermi GRB 231103A: Global MASTER-Net observations report
  35. GRB 231104A: AKO Upper Limit
  36. GRB 231104A: AstroSat CZTI detection
  37. GRB 231104A: Swift-XRT refined Analysis
  38. GRB 231104A: Fermi-LAT detection
  39. GRB 231104A: Swift/UVOT Upper Limits
  40. GRB 231104A: Enhanced Swift-XRT position
  41. GRB231104A: LCOGT Optical Upper Limits
  42. GRB 231104A: Swift detection of a bright burst
  43. GRB 231104A: Fermi GBM Final Real-time Localization
  44. GRB 231103A: Fermi GBM Final Real-time Localization
  45. GRB 231101A: Glowbug gamma-ray detection
  46. GRB 231024A: GRANDMA observations of AT2023vuc/GOTO23baj candidate
  47. GRB 231101A: Fermi GBM Final Real-time Localization
  48. GRB 231030B: GRBAlpha detection
  49. GRB 231028B: VZLUSAT-2 detection
  50. GRB 231030B: Fermi GBM Detection
  51. GRB 231030B: AstroSat CZTI detection
  52. Fermi GRB 231030B: Global MASTER-Net observations report
  53. IPN triangulation of GRB 231020A
  54. GRB 231030B: BALROG localization (Fermi Trigger 720388704 / GRB 231030832)
  55. GRB 231030B: Fermi GBM Final Real-time Localization
  56. GRB 231028A: Swift-BAT refined analysis
  57. IceCube-231027A: Upper limits from a search for additional neutrino events in IceCube
  58. LIGO/Virgo/KAGRA S231029y: Upper limits from Swift/BAT-GUANO
  59. GRB 231024A: AKO Optical Counterpart Candidate
  60. GRB 231028A: CALET Gamma-Ray Burst Monitor detection
  61. Fermi GRB 231030A: Global MASTER-Net observations report
  62. GRB 231030A: Fermi GBM Final Real-time Localization
  63. GRID detection of GRB 231020A
  64. GRB 231028A: AstroSat CZTI detection
  65. GRB 231028A: Glowbug gamma-ray detection
  66. GRB 231028A: Fermi GBM Detection
  67. Swift GRB 231028A: Global MASTER-Net observations report
  68. GRB 231028A: Swift detection of a burst
  69. GRB 231028A: Fermi GBM Final Real-time Localization
  70. GRB 231019A: Glowbug gamma-ray detection
  71. GRB 231025A: Fermi GBM Observation
  72. GRB 231024A: Fermi GBM Observation
  73. GRB 231025A: Swift/BAT-GUANO detection of a likely short burst
  74. GRB 231025A: Fermi GBM Final Localization
  75. GRB 231024A: X-shooter spectroscopy of AT2023vuc/GOTO23baj reveals a young supernova with flash ionisation features
  76. GRB 231024A: LCOGT and ZTF detections of the GOTO optical counterpart candidate
  77. GRB 231020A: AstroSat CZTI detection
  78. GRB 231020B: AstroSat CZTI detection
  79. GRB 231024A: GOTO optical counterpart candidate
  80. GRB 231024A: Fermi GBM Final Localization
  81. GRB 231018A: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  82. LIGO/Virgo/KAGRA S231020bw: Upper limits from Swift/BAT-GUANO
  83. GRB 231020A: Fermi GBM Detection
  84. GRID detection of GRB 231004A
  85. GRB 231017A: Mondy optical observations. A possible candidate for an afterglow or host galaxy.
  86. GRB 231019A: VZLUSAT-2 detection
  87. GRB 231018A: VZLUSAT-2 detection
  88. GRB 231020B: BALROG localization (Fermi Trigger 719530557 / GRB 231020900)
  89. GRB 231020B: Fermi GBM Final Real-time Localization
  90. GRB 231020A: BALROG localization (Fermi Trigger / GRB 231020790)
  91. LIGO/Virgo/KAGRA S231020ba: Upper limits from Fermi-GBM Observations
  92. GRB 231015A: NuSTAR Detection of Prompt Emission
  93. Fermi GRB 231020A: Global MASTER-Net observations report
  94. GRB 231020A: Fermi GBM Final Real-time Localization
  95. GRB 231012A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 705709044)
  96. GRB 231017A: 1.3m DFOT Optical upper limit
  97. IceCube-231004A: Upper limits from Fermi-GBM Observations
  98. GRB 231018A: GRBAlpha detection
  99. GRB 231018A: CALET Gamma-Ray Burst Monitor detection
  100. Fermi GRB 231019A: Global MASTER-Net observations report

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