Skip to main content
Circulars over Kafka event name backfill. 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.

Lucene Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

32085 results found.

  1. Fermi GRB 240112B: Global MASTER-Net observations report
  2. GRB 240109A: Swift-BAT refined analysis
  3. GRB 240112C: Swift detection of a burst with an optical counterpart
  4. GRB 240112B: Fermi GBM Final Real-time Localization
  5. GRB 240112A: GECAM detection of a burst
  6. GRB 240109A: Fermi GBM Observation
  7. GRB 240110A: AstroSat CZTI detection
  8. GRB 240108A: Glowbug gamma-ray detection
  9. GRB 231214A: ATCA Radio Upper Limits
  10. GRB 240106B: Glowbug gamma-ray detection
  11. GRB 240106A: Glowbug gamma-ray detection
  12. GRB 240109B: Fermi GBM Final Real-time Localization
  13. Konus-Wind detection of GRB 240101C
  14. GRB 231215A: radio detection with the VLA
  15. GRB 230818A: further radio observations with the VLA
  16. GRB 230812B: further radio observations with the VLA
  17. GRB 240107A: AstroSat CZTI detection
  18. GRB 240109A: Swift detection of a short burst
  19. LIGO/Virgo/KAGRA S240104bl: Upper limits from Swift/BAT-GUANO
  20. GRB 240106A: GRBAlpha detection
  21. GRB 240107A: MAXI/GSC detection
  22. GRB 240106B: Fermi GBM Final Real-time Localization
  23. GRB 240106A: Fermi GBM Final Real-time Localization
  24. IPN triangulation of GRB 240101C (short)
  25. GRB GRB240101C: Fermi GBM observation
  26. GRB 240101A: 1.3m DFOT optical observations
  27. GRB 240102A: 1.3m DFOT optical upper limit
  28. GRB 240101B: 1.3m DFOT optical upper limit
  29. GRB 240101C: Swift/BAT-GUANO detection of a short burst
  30. GRB 240102C: AstroSat CZTI detection
  31. GRB 240101C: AstroSat CZTI detection
  32. GRB 231220A: Swift-UVOT upper limit
  33. GRB 240102A: Swift-BAT refined analysis
  34. GRB 240102A: Swift/UVOT Upper Limits
  35. GRB 231230A: Swift-BAT refined analysis
  36. GRB 240101A: Swift-BAT refined analysis
  37. GRB 240101B: Swift-BAT refined analysis
  38. GRB 240102A: Enhanced Swift-XRT position
  39. GRB 240101B: Swift-XRT refined Analysis
  40. GRB 240102A: Swift-XRT refined Analysis
  41. GRB 240102B (Fermi GBM trigger 725926335/240102925) is not a GRB
  42. GRB 240102A: LCOGT Optical Upper Limits
  43. GRB240102A: BOOTES-6/DPRT optical upper limit
  44. GRB 240102B: Fermi GBM Final Real-time Localization
  45. GRB 240101B: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
  46. GRB 240102A: Swift detection of a burst
  47. GRB 240101A: Terskol Zeiss-2000 optical observations
  48. GRB 240101C: GRBAlpha detection
  49. GRB 240101B: Swift/UVOT Upper Limits
  50. GRB 240101A: Swift/UVOT Upper Limits
  51. GRB 240101A: Swift-XRT refined Analysis
  52. GRB 240101B: Enhanced Swift-XRT position
  53. GRB 240101B: KAIT Optical Upper Limit
  54. GRB 240101A: KAIT Optical Upper Limit
  55. GRB 240101A: Enhanced Swift-XRT position
  56. GRB 240101C: Fermi GBM Final Localization
  57. GRB 240101B: Swift detection of a burst
  58. GRB 240101A: Swift detection of a burst
  59. GRB231230A: Fermi GBM Observation
  60. GRB 231230A: Swift-XRT refined Analysis
  61. GRB 231230A: GOTO optical upper limits
  62. GRB 231230A: Enhanced Swift-XRT position
  63. GRB 231230A: Swift/UVOT Upper Limits
  64. GRB 231230A: NOT optical upper limits
  65. GRB 231230A: Prompt enhanced Swift-XRT position
  66. GRB 231230A: Swift detection of a burst
  67. GRB 231230A: Fermi GBM Final Real-time Localization
  68. GRB 231210B: BOOTES-7 optical upper limit
  69. LIGO/Virgo/KAGRA S231224e: Upper limits from Swift/BAT-GUANO
  70. IPN triangulation of GRB 231224A (short)
  71. GRB 231224A: Fermi GBM Final Real-time Localization
  72. GRB 231222B: GRBAlpha detection
  73. GRB 231222B: Swift-XRT afterglow detection
  74. GRB 231222B: Fermi GBM Detection
  75. GRB 231222B: Fermi-LAT detection
  76. GRB 231222A: Tiled Swift observations
  77. GRID detection of GRB 231215A
  78. GRB 231222A: Fermi GBM Final Real-time Localization
  79. GRB 231220A: Swift-XRT follow-up observations
  80. GRB 231220A: Swift ToO observations
  81. GRB 231220A: Swift/BAT-GUANO arcminute localization of a long burst
  82. GRB 231220A: Fermi GBM Final Real-time Localization
  83. GRB 231210B: new optical transient detected with the Greenhill Observatory University of Tasmania within the BAT-Swift enhanced position
  84. GRB 231219A: Fermi GBM Final Real-time Localization
  85. GRID detection of GRB 231205B
  86. GRID detection of GRB 231205A
  87. GRB 231216A: GAD Observatory, La Spezia, Italy upper limit
  88. GRB 231214B: Fermi GBM observation
  89. GRB 231216A: optical upper limits from the INAF Asiago Observatory
  90. GRB 231216A: 10.4 m GTC optical upper limit
  91. GRB 231215A: AMI-LA radio detection
  92. GRB 231216A: Nanshan/HMT optical upper limit
  93. GRB 231216A: LCOGT Optical Upper Limits
  94. GRB 231216A: Osservatorio Astronomico Nastro Verde upper limit
  95. GRB 231216A: Swift-XRT refined analysis correction
  96. GRB 231215A: Osservatorio Astronomico Nastro Verde upper limit
  97. GRB 231216A: Swift-XRT refined Analysis
  98. GRB 231216A: AST3-3 YaoAn Optical Upper Limit
  99. GRB 231216A: REM NIR upper limits
  100. GRB 231216A: Swift/UVOT Upper Limits

Advanced

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