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"

16162 results found.

  1. GRB 121226A: 5.8 GHz VLA observations
  2. GRB 121229A: Swift/UVOT Upper Limits
  3. Skynet/PROMPT observations of GRB121229a
  4. GRB 121226A: 10.4m GTC optical observations
  5. GRB 121226A: Swift/UVOT Upper Limits
  6. GRB 121226A: NOT optical upper limit
  7. GRB 121226A: Optical Observations
  8. GRB 121226A: MITSuME Okayama Optical upper limits
  9. GRB 121226A: Zadko observatory - Gingin optical observations
  10. GRB 121226A: BOOTES-4/MET optical observations
  11. GRB 121217A: ATCA 44GHz upper limit
  12. GRB 121217A: Swift/UVOT Detection
  13. GRB 121209A: LOAO Observation
  14. GRB 121209A: Swift/UVOT Upper Limits
  15. GRB 121212A: PdBI mm observations
  16. GRB121212A: NOT optical imaging
  17. GRB 121211A: Continued RATIR Optical and NIR Observations, Fading
  18. GRB 121212A: Maidanak optical observations
  19. GRB 121211A: RATIR Optical and NIR Observations
  20. GRB 121212A: RAPTOR Limits During Gamma-Ray Emitting Interval
  21. GRB 121211A: RAPTOR Limits During Gamma-Ray Emitting Interval
  22. GRB 121212A: optical observations in ISON-NM observatory
  23. GRB 121211A: MITSuME Okayama Optical Observation
  24. GRB 121211A: Keck/LRIS redshift
  25. GRB 121211A - Faulkes Telescope North afterglow confirmation
  26. GRB 121211A: Swift detection of a burst with an optical counterpart
  27. GRB 121209A: Keck observations
  28. GRB 121209A: CARMA 3mm Observations
  29. GRB 121209A: EVLA Observations
  30. GRB121209A: RATIR Optical and NIR Upper Limits
  31. GRB 121209A: GROND optical afterglow candidate
  32. GRB 121209A: Gemini-South imaging
  33. GRB 121128A: Optical Observations
  34. GRB 121202A: Swift/UVOT Upper Limits
  35. GRB 121202A: TAROT Calern observatory optical observations
  36. GRB 121201A: GROND afterglow observations and photometric redshift
  37. GRB 121201A: BOOTES-4 optical observations
  38. GRB 121201A: a GRB with an optical counterpart
  39. GRB 121128A: optical observation in Mondy observatory
  40. GRB 121128A: MITSuME Akeno Optical upper limits
  41. GRB 121125A: optical upper limit
  42. GRB 121128A: optical observation in Mondy observatory
  43. GRB 121128A: WSRT radio observation
  44. GRB 121128A: RAPTOR Detection During Gamma-Ray Emitting Interval
  45. GRB 121128A, Swift-BAT refined analysis
  46. GRB 121128A: FTN optical afterglow confirmation
  47. GRB 121128A: Swift detection of a burst with an optical counterpart
  48. GRB 121123A: Swift/UVOT Observations
  49. GRB 121125A: LOAO Observation
  50. GRB 121125A: MASTER-NET optical observations
  51. GRB 121125A: Swift detection of a burst with optical counterpart
  52. GRB 121123A: GROND observations
  53. GRB 121123A: optical observations
  54. GRB 121123A: BOOTES-4 and IAC80 optical observations
  55. GRB 121123A: NOT optical observations
  56. GRB 121123A: MASTER-NET optical limit
  57. GRB 121123A: GMG optical observation
  58. GRB 121123A: Swift detection of a burst with optical counterpart
  59. GRB 121108A: optical upper limit
  60. GRB 121117A: Optical observations
  61. GRB 121117A: optical upper limit
  62. GRB 121117A: Swift/UVOT Observations
  63. GRB 121117A: MASTER prompt optical limit
  64. GRB 121117A: ROTSE-III Optical Limits
  65. GRB 121117A: BOOTES-3 early optical upper limit
  66. GRB 121108A: Swift/UVOT Upper Limits
  67. GRB 121108A: Xinglong TNT upper limit
  68. GRB 121108A : Lulin/TRIPOL2 Optical Limits
  69. GRB 121108A: Optical observations
  70. GRB 121108A: MITSuME Ishigakijima upper limits
  71. GRB 121108A: Weihai observatory optical observations
  72. GRB 121108A: MASTER early prompt optical limit
  73. GRB 121108A: TAROT Calern observatory optical observations
  74. GRB 121102A: Swift/UVOT Upper Limits
  75. GRB 121031A: Swift/UVOT Upper Limits
  76. GRB 121027A: X-shooter redshift confirmation
  77. GRB 121024A: SMARTS optical/IR afterglow observations
  78. GRB 121027A: GROND Confirmation of Rebrightening
  79. GRB 121028A: RAPTOR Limits During Gamma-Ray Emitting Interval
  80. GRB 121027A: MASTER early prompt optical limit
  81. GRB 121028A: MITSuME Okayama Optical upper limits
  82. GRB 121011A: optical observations
  83. GRB 121024A: optical observations
  84. GRB 121024A: EVLA Detection
  85. GRB 121024A: Swift/UVOT Observations
  86. GRB 121024A: CARMA 3mm Detection
  87. GRB 121024A: GMG optical observation
  88. GRB 121024A: MITSuME Ishigakijima upper limits
  89. GRB 121024A: MITSuME Okayama Optical upper limits
  90. GRB 121024A: PAIRITEL NIR Detection
  91. GRB 121024A: GROND Detection of the Optical/NIR Afterglow
  92. Skynet PROMPT/Dolomiti observations of GRB121024A
  93. GRB 121024A: BOOTES-1B optical detection
  94. GRB 121024A: TAROT Calern observatory optical detection of a bright counterpart
  95. GRB 121024A: Swift detection of a burst with an optical counterpart
  96. GRB 121011A: early optical light curve
  97. GRB 121017A: Swift/UVOT Upper Limits
  98. GRB 121017A: GROND Observations
  99. GRB 121017A: 1.23m CAHA R-band observations
  100. GRB 121017A optical observations

Advanced

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