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"

20967 results found.

  1. GRB 111209A: REM NIR detection
  2. GRB 111209A: TAROT La Silla observatory optical detection
  3. GRB 111208A: Swift XRT/UVOT observations
  4. GRB 111205A: Swift XRT Observations
  5. GRB 111204A: TNG NIR observations
  6. GRB 111201A: GMG optical observation
  7. GRB 111204A: GROND Observations
  8. GRB 111204A: Swift/UVOT Upper Limits
  9. GRB 110921A: optical observations in Maidanak observatory
  10. GRB 111204A: MASTER optical observations
  11. GRB 111201A: Swift/UVOT Upper Limits
  12. GRB111201A: Swift-XRT observations
  13. GRB 111129A: Swift/UVOT Detection
  14. GRB 111129A, GROND afterglow observations
  15. GRB 111123A: Swift/UVOT Upper Limits
  16. GRB 111123A - NOT optical observations
  17. GRB 111123A, GROND observations
  18. GRB 111123A: GMG optical observation
  19. GRB 111117A: Refined Chandra Astrometry
  20. GRB 111121A: Swift/UVOT Upper Limits
  21. GRB 111121A: Magellan/Megacam observations
  22. GRB 111117A: Chandra detection of the afterglow
  23. GRB 111117A: Gemini Afterglow Limits
  24. GRB 111117A: further NOT observations
  25. GRB 111117A: EVLA observations
  26. GRB 111117A: TNG observations
  27. GRB 111117A: Swift/UVOT Upper Limits
  28. GRB 111117A: GROND observations
  29. GRB 111117A: Gemini host observation
  30. GRB111117A: Magellan IMACS observations
  31. GRB111107A: Further ATCA observations - no detection
  32. GRB 111117A: NOT observations
  33. GRB 111117A: Chandra ToO observation scheduled
  34. GRB 111117A: GMG upper limit
  35. GRB111107A: ATCA observations - upper limit and a possible detection
  36. XRF 111111A/MAXI J0158-744: MAXI GSC and SSC detection of a soft X-ray transient near SMC
  37. GRB 111109A: Swift/UVOT Photometry
  38. GRB 111109A: Swift-XRT observations
  39. Continued Skynet observations of GRB111107A
  40. GRB 111107A: VLT/X-shooter spectroscopy
  41. GRB 111107A: Swift/UVOT Afterglow Analysis
  42. GRB 111107A: Gemini-South Redshift
  43. GRB 111107A: GROND observations
  44. Skynet observations of GRB 111107A
  45. GRB 111103B : WIYN 3.5m NIR observations
  46. GRB111103B Swift/UVOT Upper Limits
  47. GRB 111103B: optical observations from TAU, Ka-Dar
  48. Trigger 506913: MASTER detection of Swift J1922.7-1716 optical counterpart
  49. GRB 111022B: MASTER OT observations
  50. GRB 111103B: optical observations
  51. GRB 111103B: Swift detection of a strong burst from a GRB or Galactic source
  52. GRB 111029A: RAPTOR Limits During the Gamma-ray Emitting Interval
  53. GRB 111029A: Super-LOTIS early limits
  54. GRB 111029A: TNT optical upper limit, Correction to GCN 12503
  55. GRB 111029A: PAIRITEL NIR Upper Limits
  56. GRB 111029A: Swift/UVOT Upper Limits
  57. GRB 111029A: TNT optical upper limit
  58. GRB 111029A: Faulkes Telescope North observations
  59. GRB 111022B: EVLA observations - correction to GCN 12495
  60. GRB 111022B: EVLA observations
  61. GRB 111022B: 10.4m GTC z'-band observations
  62. GRB 111022B: BTA Optical Observations
  63. GRB 111024A: MAXI/GSC detection of a burst
  64. GRB 111022B: Swift/UVOT upper limits
  65. GRB 111022A: Swift/UVOT Upper Limits
  66. GRB 111022B: Gemini infrared observations
  67. GRB 111022B: NOT observations
  68. GRB 111020A: Gemini-South additional observations and limit on an optical afterglow
  69. GRB 111020A: EVLA observations
  70. GRB 111020A: Gemini-South i-band observations
  71. GRB 111020A: Swift/UVOT Upper Limits
  72. GRB 111020A: Faulkes Telescope South observations
  73. GRB 111018A: Swift/UVOT Upper Limits
  74. GRB 110918A: Optical light curve for days 1.4 to 16.3
  75. GRB 111018A: GROND Upper Limits
  76. GRB111016A : WIYN 3.5m NIR observations
  77. GRB 111016A: Gemini Detection of the NIR Counterpart
  78. GRB 111016A: Swift/UVOT Detection of a Source
  79. GRB 111016A: P60 Afterglow Candidate
  80. GRB 111016A: Swift-XRT observations
  81. GRB 110921A: optical observations
  82. GRB 111008A : miniTAO/ANIR NIR observations
  83. EVLA 22 GHz Detection of GRB 111008A
  84. GRB 111008A: Swift/UVOT Upper Limits
  85. GRB 111008A: IAC80 I-band observations
  86. GRB 111008A: VLT/X-shooter spectroscopy
  87. GRB 111008A: Gemini spectroscopic redshift
  88. GRB 111008A, GROND observations
  89. GRB 111008A: Gemini optical counterpart
  90. GRB 111005A: ATCA 18 GHz detection
  91. GRB 111005A: ATCA radio upper limit
  92. GRB 111005A : miniTAO/ANIR NIR observations
  93. GRB 111005A: EVLA Observations
  94. GRB 111005A: VLT optical observations
  95. GRB 111005A: GROND NIR observations
  96. GRB 111005A: VLT IR observations
  97. GRB 111005A: bright galaxy in error circle
  98. GRB 110905A / MAXI J1836-194: optical monitoring
  99. Skynet/Dolomiti observations of GRB 110928A
  100. Skynet observations of GRB 110928A

Advanced

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