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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"

27815 results found.

  1. GRB 251013C: EP-FXT counterpart detection
  2. GRB 251013C: AstroSat CZTI detection
  3. GRB 251011A: Swift/BAT-GUANO arcminute localization of a burst
  4. GRB 251013D: Swift/BAT-GUANO arcminute localization of a burst
  5. GRB 251013C: ALMA detection
  6. GRB 251013C: SVOM/COLIBRÍ (FM-GFT) detection of the optical counterpart
  7. GRB 251013C: DDOTI detection of the optical afterglow
  8. Swift GRB 251014A: Global MASTER-Net observations report
  9. GRB 251014A: Swift detection of a possibly-short burst
  10. GRB 251014A: Fermi GBM Final Real-time Localization
  11. GRB 251013C: Swift-XRT counterpart detection
  12. GRB 251013C: GOTO optical afterglow detection
  13. GRB 251013C: LCO optical afterglow detection
  14. GRB 251013C: NOT spectroscopic redshift z = 0.572
  15. GRB 251013C: LAST detection of optical counterpart
  16. GRB 251013C: BOOTES-6 early optical detection
  17. GRB 251013D: Fermi GBM Final Real-time Localization
  18. GRB 251013C: SVOM detection of a burst
  19. GRB 251013C: Fermi GBM Final Real-time Localization
  20. GRB 251003A: Mondy optical upper limit
  21. GRB 251013B: Fermi GBM Final Real-time Localization
  22. GRB 251013A: Fermi GBM Final Real-time Localization
  23. GRB 251011B inspection: MASTER orphan GRB detection
  24. GRB 251011A: Insight-HXMT detection
  25. GRB 251011B: Swift/UVOT Upper Limits
  26. GRB 251012A: Fermi GBM Final Real-time Localization
  27. GRB 251011B: SVOM/GRM observation
  28. GRB 251011B: Swift-XRT refined Analysis
  29. GRB 251011B: Fermi GBM Observation
  30. GRB 251011B : MASTER optical observations
  31. GRB 251011C: Fermi GBM Final Real-time Localization
  32. GRB 251011B: Enhanced Swift-XRT position
  33. GRB 251010A: AstroSat CZTI detection
  34. GRB 251011A: AstroSat CZTI detection
  35. GRB 251011B: Swift detection of a burst
  36. GRB 251011B: Fermi GBM Final Real-time Localization
  37. GRB 251011A: Fermi GBM Final Real-time Localization
  38. GRB 251007B: Swift/UVOT Upper Limits
  39. GRB 251010A: Fermi GBM Final Real-time Localization
  40. GRB251007A: Swift/UVOT Detection
  41. GRB 251009A: GECAM-B detection of a short burst
  42. GRB 251009A: Insight-HXMT detection of a short burst
  43. GRB 251009B (short): Glowbug gamma-ray detection
  44. GRB 251009B: Insight-HXMT detection of a short burst
  45. GRB 251007A: Swift-BAT refined analysis
  46. GRB 251007A: SVOM/GRM observation
  47. GRB 251007A: Insight-HXMT detection
  48. GRB 251006A: CALET Gamma-Ray Burst Monitor detection
  49. SVOM/sb25101004: SVOM detection of a stellar flare
  50. GRB 251009A: Fermi GBM Final Localization
  51. GRB 250916A: TERI Gamma-ray detection
  52. GRB 250919A: TERI gamma-ray detection
  53. GRB 251006A: Fermi GBM Observation
  54. GRB 251007A: 1.5m OSN and 2.2m CAHA optical follow-up
  55. IceCube alert 141456_888784 retraction
  56. GRB 251003A: Fermi GBM Observation
  57. GRB 251007B: COLIBRÍ optical upper limit
  58. GRB 251007A: AstroSat CZTI detection
  59. GRB 251006B/EP251006a: EP-FXT afterglow detection
  60. GRB 250917B: iTelescope T-26 upper limit
  61. GRB 251007A: Swift-XRT refined Analysis
  62. GRB 251007A: Enhanced Swift-XRT position
  63. GRB 251007B: Swift-XRT refined Analysis
  64. GRB 251007B: Enhanced Swift-XRT position
  65. GRB 251007A: NOT optical observations
  66. GRB 251007A: AKO Optical Upper Limit
  67. GRB 251007A: CALET Gamma-Ray Burst Monitor detection
  68. GRB 251006B: Insight-HXMT detection
  69. GRB 251007A: SVOM/C-GFT optical observations
  70. GRB 251005C: PRIME J-band upper limit
  71. Swift GRB 251007B: Global MASTER-Net observations report
  72. GRB 251007A: Glowbug gamma-ray detection
  73. Swift GRB 251007A: Global MASTER-Net observations report
  74. GRB 251007B: SVOM detection of a faint burst
  75. GRB 251007B: Swift detection of a burst
  76. GRB 251007A: Swift detection of a burst with an optical counterpart
  77. GRB 251006A: Swift/BAT-GUANO subthreshold detection of a short burst
  78. GRB 251005B: Glowbug gamma-ray detection
  79. GRB 251006B/EP251006a: EP-FXT follow-up observation
  80. GRB 251006B/EP251006a: EP-WXT detection
  81. GRB 251005C: SVOM/GRM observation of a likely short GRB
  82. GRB 251006B: Fermi GBM Final Real-time Localization
  83. GRB 251006A (short): Glowbug gamma-ray detection
  84. GRB 251005C: COLIBRÍ optical observations
  85. GRB 251003A: LAST optical observations
  86. GRB 251002A: LAST optical observations
  87. GRB 251006A: Fermi GBM Final Real-time Localization
  88. GRB 251005C: SVOM/VT optical candidate
  89. GRB 251005C: AstroSat CZTI detection
  90. GRB 251005C: Swift/UVOT Upper Limits
  91. GRB 250902A: MSU cubesats detection
  92. GRB 251005C: Swift-XRT refined Analysis
  93. GRB 251005C: Fermi GBM Observation
  94. Swift GRB 251005A: Global MASTER-Net observations report
  95. GRB 251005C: Enhanced Swift-XRT position
  96. GRB 251005C: GOTO optical upper limits
  97. GRB 251005C: Swift detection of a burst
  98. GRB 251005B: Fermi GBM Final Real-time Localization
  99. GRB 251005A: Fermi GBM Final Localization
  100. GRB 251002A: Insight-HXMT detection

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