Skip to main content
New! BOOM Notices and Schema v7.0.0. 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"

35442 results found.

  1. GRB 081226A: Swift UVOT Upper Limits
  2. GRB 081226: Second epoch of Gemini-South imaging
  3. GRB 081226A: Swift-BAT refined analysis
  4. GRB 081226B: a short-hard GRB detected by INTEGRAL
  5. GRB 081226: Gemini-South spectrum of possible afterglow
  6. GRB 081226: Gemini-South imaging
  7. GRB 081226: GROND afterglow candidate
  8. GRB 081226: ROTSE-III Optical Limits
  9. GRB 081226: Swift detection of a possible short-hard burst
  10. GRB 080810: optical observations
  11. GRB 081211B: optical observations
  12. GRB081224: LAT retraction
  13. GRB 081224: Swift-XRT observation
  14. GRB 081222: MITSuME optical observation
  15. GRB 081224: Fermi GBM Detection & LAT Localization
  16. GRB 080810: optical observations
  17. Konus-Wind observation of GRB 081222
  18. GRB 081223: Fermi GBM detection
  19. GRB 081221: GROND observations
  20. GRB 081222: Gemini-N confirmation of redshift z=2.77
  21. GRB 081222:Optical afterglow observation
  22. VLA radio upper limit on GRB 081222
  23. GRB 081222: Fermi GBM observation
  24. Fermi Gamma-ray Burst Monitor trigger 251687595 reclassification
  25. GRB 081222: Gemini-South absorption redshift
  26. GRB 081221: Probable host galaxy in Keck imaging
  27. GRB 081204C: Fermi GBM detection
  28. GRB 081222, Swift-BAT refined analysis
  29. GRB 081221, Swift-BAT refined analysis
  30. GRB081222 optical limit by "Pi of the Sky"
  31. Konus-Wind observation of very bright GRB 081215A
  32. GRB 081222: Swift XRT refined analysis
  33. GRB081221: Fermi GBM observation
  34. Swift/UVOT observations of GRB 081221
  35. IPN triangulation of bright GRB 081215A
  36. GRB 081221: Swift-XRT Refined Analysis
  37. GRB 081221: pseudo-redshift (pz=0.7) from the spectral parameters of the prompt emission
  38. GRB 081222: Faulkes Telescope South observations
  39. GRB 081221: Gemini-N nIR imaging
  40. GRB081203A: BTA observation
  41. Konus-Wind observation of GRB 081221
  42. GRB 081222: GROND Detection of the Optical/NIR Afterglow
  43. GRB081222: REM candidate afterglow
  44. GRB 081222: Swift detection of a burst with a bright optical afterglow
  45. GRB 081221: Enhanced Swift-XRT position
  46. GRB 081221: further NOT observations
  47. GRB 081221: NOT observations
  48. GRB 081221: Swift detection of a burst
  49. GRB 081217: Fermi GBM detection
  50. GRB 081211B: Further Swift-XRT analysis
  51. GRB 081215B: Fermi GBM detection
  52. GRB 081216: Suzaku WAM observation of the prompt emission
  53. GRB 081216 : Fermi GBM observation
  54. GRB 081215A: Fermi GBM detection (correction to event fluence)
  55. GRB 081215A: Fermi GBM detection
  56. IPN localization of short hard GRB 081216
  57. GRB 081211B - possibly a short burst with extended emission
  58. GRB 081118: Zadko observations
  59. GRB 081215A: Gamma Repeater?
  60. GRB 0811215A: MASTER prompt optical observations
  61. GRB 081215A: Andromeda inside Fermi error box: MASTER observations
  62. GRB 0811215A: Andromeda inside Fermi error box: MASTER observations
  63. Possible GRB 081211B: Swift/UVOT Upper Limits
  64. GRB 081213: Fermi GBM detection
  65. GRB 081210: optical observations
  66. Possible GRB 081211B - Swift-XRT analysis
  67. GRB 081207: Fermi GBM detection
  68. GRB 081209: Fermi GBM detection
  69. Fermi Gamma-ray Burst Monitor trigger 250533995 is not a GRB
  70. GRB 081007: Detection of a Supernova
  71. GRB 081211B(?): Possible burst detection from Swift-BAT slew data
  72. GRB 081210: Xinglong TNT R band Upper Limits
  73. GRB 081210, SMARTS optical/IR observations
  74. GRB 081211: Swift-BAT refined analysis
  75. GRB 081211: Swift XRT refined analysis
  76. GRB 081211: Swift/UVOT detection of an optical afterglow
  77. GRB 081211: Enhanced Swift-XRT position
  78. GRB 081210: Swift/UVOT refined analysis
  79. GRB 081211: Swift detection of a burst
  80. GRB 081210: Swift-XRT refined analysis
  81. GRB081203B: optical observations
  82. GRB 081210: Enhanced Swift-XRT position
  83. GRB 081210: Swift-BAT refined analysis
  84. GRB 081210: Swift detection of a burst with optical afterglow
  85. Konus-Wind observation of GRB 081209
  86. IPN triangulation of short hard GRB 081209
  87. GRB 081203A: optical observations
  88. GRB 081206C: Fermi GBM detection
  89. Radio observation of GRB 081121 with ATCA
  90. Radio observation of GRB 081118 with ATCA
  91. GRB 081206B: Fermi GBM detection
  92. GRB 081206: Fermi GBM detection
  93. GRB 081128: afterglow observations
  94. GRB 081203B: Suzaku WAM observation of the prompt emission
  95. GRB 081203B: Additional Gemini imaging
  96. Radio observation of GRB 081109 with ATCA
  97. Radio observation of GRB 081104 with ATCA
  98. Radio observation of GRB 081029 with ATCA
  99. Radio observation of GRB 081008 with ATCA
  100. GRB081203A: Ashra-1 observation of early optical and VHE-neutrino emission

Advanced

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