Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! 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.

Advanced Search Examples (click to copy):

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

36189 results found.

  1. Fermi Gamma-ray Burst Monitor trigger 741356809/240629519 is not a GRB
  2. IPN triangulation of GRB 240619C
  3. GRB 240628A: BALROG localization (Fermi Trigger 741288821 / GRB 240628732)
  4. GRB 240627A: NuSTAR Detection of the long GRB
  5. GRB 240615A: SAI CMO J- band observations
  6. GRB 240627A: AstroSat CZTI detection
  7. EP240626a: Montarrenti Observatory optical upper limit
  8. EP240626a: KAIT optical upper limit
  9. GRB 240624A: Swift-BAT refined analysis
  10. Konus-Wind detection of GRB 240619A
  11. Fermi GRB 240625B: Global MASTER-Net observations report
  12. GRB 240624B: CALET Gamma-Ray Burst Monitor detection
  13. GRB 240625B: Fermi GBM Final Real-time Localization
  14. GRB 240625A: Fermi GBM Observation
  15. GRB 240624B: GRBAlpha detection
  16. GRB 240625A: Fermi GBM Final Real-time Localization
  17. GRB240624A: Fermi GBM Observation
  18. LIGO/Virgo/KAGRA S240622h: Upper limits from Swift/BAT-GUANO
  19. LIGO/Virgo/KAGRA S240621dy: Upper limits from Swift/BAT-GUANO
  20. LIGO/Virgo/KAGRA S240618ah: Upper limits from Swift/BAT-GUANO
  21. Swift GRB 240624A: Global MASTER-Net observations report
  22. GRB240615A: Gemini-North observations of the BAT and XRT positions
  23. Fermi GRB 240624A: Global MASTER-Net observations report
  24. GRB 240624B: Fermi GBM Final Real-time Localization
  25. GRB240615A: Gemini-North observations of the BAT and XRT positions
  26. GRB 240624A: Fermi GBM Final Real-time Localization
  27. GRB 240619A: detection of a radio counterpart with AMI-LA
  28. GRB 240624A: Swift detection of a burst
  29. GRB 240619A: J-band detection with WINTER (duplicate submission of GCN 36739)
  30. GRB 240619A: J-band detection with WINTER
  31. EP240618a: NOT optical counterpart candidate
  32. GRB 240529A: JinShan optical observations
  33. IPN triangulation of GRB 240615A (short)
  34. GRB 240619A: GRBAlpha detection
  35. GRB 240619A: Swift-XRT probable afterglow detection
  36. GRB 240619A: Swift ToO observations
  37. GRB 240619A: CALET Gamma-Ray Burst Monitor detection
  38. GRB 240619C: NuSTAR automated detection of the GRB
  39. GRB 240619A: Fermi GBM Observation
  40. Fermi GBM Sub-Threshold Detection of GRB 240619C
  41. GRB 240619A: GOTO candidate optical afterglow
  42. EP240618a: Abastumani optical observationsEP240618a
  43. GRB 240615A: NOT optical observations
  44. GRB 240619C: AstroSat CZTI detection
  45. Fermi GRB 240619A: Global MASTER-Net observations report
  46. EP240617a: STEP/T80S optical limits
  47. GRB 240615A: possible transient detection from Wendelstein observations
  48. Fermi Gamma-ray Burst Monitor trigger 740474239/240619304 is not a GRB
  49. GRB 240619B: Fermi GBM Final Real-time Localization
  50. GRB240615A: 1.3m DFOT optical upper limit
  51. GRB 240619A: BALROG localization (Fermi Trigger 740461416 / GRB 240619155)
  52. GRB 240619A: Fermi GBM Final Real-time Localization
  53. EP240617a: BOOTES-6/DPRT optical upper limit
  54. EP240617a is likely a GRB event
  55. LIGO/Virgo/KAGRA S240615ea: Upper limits from Swift/BAT-GUANO
  56. LIGO/Virgo/KAGRA S240615dg: Upper limits from Swift/BAT-GUANO
  57. GRB 240615A: J-band upper limits from WINTER
  58. GRB 240615A: Fermi GBM Observation
  59. GRB 240615A: Swift-XRT observations
  60. GRB 240615A: GECAM detection
  61. GRB 240615A: FLWO-1.2m optical upper limits
  62. Fermi GRB 240616A: Global MASTER-Net observations report
  63. Konus-Wind detection of GRB 240615A (short/hard)
  64. GRB 240615A: GOTO optical upper limits
  65. GRB 240616A: Fermi GBM Final Real-time Localization
  66. GRB 240615A: Swift ToO observations
  67. GRB 240615A: Swift/BAT-GUANO arcminute localization of a short burst
  68. GRB 240615A: Fermi GBM Final Real-time Localization
  69. GRB 240603A: VZLUSAT-2 detection
  70. GRB 240612A: GRBAlpha detection
  71. GRB 240613A: Fermi GBM Final Real-time Localization
  72. Fermi GRB 240612B: Global MASTER-Net observations report
  73. Fermi GRB 240612A: Global MASTER-Net observations report
  74. GRB 240612B: Fermi GBM Final Real-time Localization
  75. GRB 240612A: Fermi GBM Final Real-time Localization
  76. GRB 240607A: GECAM detection of a bright long burst
  77. Fermi GRB 240611A: Global MASTER-Net observations report
  78. Konus-Wind detection of GRB 240607A
  79. GRB 240611A: Fermi GBM Final Real-time Localization
  80. GRB 240529A: LBT optical detection and late temporal decay
  81. GRB 240529A : MITSuME Akeno optical afterglow detection
  82. Fermi GRB 240610A: Global MASTER-Net observations report
  83. GRB 240610A: Fermi GBM Final Real-time Localization
  84. IPN triangulation of GRB 240607A
  85. Fermi Gamma-ray Burst Monitor trigger 739632045/240609556 is not a GRB
  86. Fermi GRB 240608A: Global MASTER-Net observations report
  87. Konus-Wind detection of GRB 240606B
  88. GRB 240608A: Fermi GBM Final Real-time Localization
  89. Fermi GRB 240607A: Global MASTER-Net observations report
  90. GRB 240529A: NOEMA detection
  91. GRB 240607A: Fermi GBM Observation
  92. GRB 240606B: Fermi GBM Observation
  93. Swift Trigger 1235109: consistent with noise and not astrophysical
  94. GRB 240607A: AstroSat CZTI detection of bright long burst
  95. GRB 240607A: Fermi GBM detection of a very bright burst
  96. GRB 240529A: radio detection with AMI-LA
  97. GRB 240607A: BALROG localization (Fermi Trigger 739450879 / GRB 240607459)
  98. GRB 240607A: Fermi GBM Final Real-time Localization
  99. GRB 240606B: GECAM-B detection a long burst
  100. GRB 240606B: Swift-XRT afterglow detection

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov