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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"
  1. GRB 080710: Optical observation with MITSuME Okayama
  2. GRB 080710: TLS observations, steepening afterglow decay
  3. GRB 080702B: Swift XRT confirmation of the afterglow
  4. GRB 080710: Lick IR detection
  5. GRB 080710, Swift-BAT refined analysis
  6. GRB 0800707: optical observations
  7. GRB 080710: Rapid PROMPT Observations
  8. GRB 080710: Swift-XRT refined analysis
  9. GRB080710: Swift/UVOT observations
  10. GRB 080710: Enhanced Swift-XRT position
  11. GRB 080710: Faulkes Telescope North observations
  12. GRB 080710: Gemini spectroscopy and probable redshift
  13. UVOT white band observations of GRB080710
  14. GRB 080710: REM afterglow confirmation & brightening
  15. GRB 080710: KAIT OA candidate
  16. GRB 080710: Swift XRT position
  17. GRB 080710: Swift detection of a burst
  18. GRB 080707: possible break in the X-rays
  19. New Swift-XRT GRB products available online.
  20. GRB 080707: GROND Confirmation of the Optical Afterglow
  21. UVOT observations of GRB080707
  22. GRB 080707, Swift-BAT refined analysis
  23. GRB 080707: Swift XRT refined analysis
  24. GRB 080707: Enhanced Swift-XRT position
  25. GRB 080707: VLT redshift
  26. GRB 080707: GROND Detection of the Optical Afterglow Candidate
  27. GRB 080707: Swift detection of a burst
  28. Refined analysis of Swift Trigger 316063, is IGR J08408-4503
  29. Trigger 316063: Swift detection of a transient
  30. GRB 080703: GROND Upper Limits
  31. GRB 080702B: GROND Upper Limits
  32. GRB 080703: Swift-XRT refined analysis
  33. GRB 080703: UVOT Follow-Up Observation
  34. GRB 080703: VLT observations of the afterglow
  35. GRB 080703: Enhanced Swift-XRT position
  36. GRB 080703, Swift-BAT refined analysis
  37. GRB 080702B Swift-BAT refined analysis
  38. GRB 080703: Swift detection of a burst with optical afterglow
  39. GRB 080703A: ROTSE-III Detection of Optical Counterpart
  40. No radio detection from the short GRB 080702A
  41. GRB 080702b: LCO optical observations
  42. Swift/UVOT observation of GRB080702A
  43. GRB 080702B: Swift XRT and UVOT observations
  44. GRB 080625: Suzaku WAM observation of the prompt emission
  45. GRB 080702A: MITSuME Akeno optical upper limits
  46. GRB 080701A: Early RAPTOR optical limits
  47. Swift Trigger 315630: Swift/UVOT Upper Limits
  48. GRB 080702A, Swift-BAT refined analysis
  49. GRB 080702A: Swift-XRT Team refined analysis
  50. GRB 080702B : Burst detected in BAT during Swift slew
  51. GRB 080702A: Enhanced Swift-XRT position
  52. Swift Trigger 315630: TLS R-band observation
  53. Swift Trigger 315630: Probably not a GRB
  54. GRB 080702: Swift detection of a short burst
  55. GRB 080701: Swift-XRT refined analysis
  56. GRB 080701A, VATT optical upper limit
  57. TLS I-Band Observation of GRB 080701A
  58. GRB 080701A: Swift/UVOT Upper Limits
  59. GRB 080701A: Early Super-LOTIS Observations
  60. GRB 080701: Enhanced Swift-XRT position
  61. GRB 080701A, Swift-BAT refined analysis
  62. Trigger 315630: Swift detection of a possible burst
  63. GRB 080701: Swift-XRT Prompt Analysis
  64. GRB 080701: Swift detection of a burst
  65. GRB 080623: Suzaku WAM observation of the prompt emission
  66. GRB 080625: Swift/UVOT Follow-Up Observations
  67. GRB 080625: Further observations from OSN
  68. GRB 080625:Swift-XRT detection of the afterglow
  69. GRB 080625: Swift/UVOT Detection of an Optical Afterglow
  70. GRB 080625: Observations at OSN
  71. GRB 080625: Gamma Ray Burst Localization by SuperAGILE
  72. GRB 080623: GROND upper limits
  73. GRB080623: Swift UVOT followup observations
  74. GRB 080623: Swift-XRT refined analysis
  75. GRB 080623, Swift-BAT refined analysis
  76. GRB 080623: Enhanced Swift-XRT position
  77. GRB 080623: TAROT La Silla observatory optical observations
  78. GRB 080623: Swift/UVOT Non-Detection of an Optical Afterglow
  79. GRB 080623: Swift XRT prompt analysis
  80. GRB 080623: Swift detection of a burst
  81. Swift trigger 314975 is not a GRB
  82. Swift-BAT trigger 314975 possible burst
  83. GRB080607: optical observation
  84. GRB 080603b: optical observation
  85. GRB 070809: Putative host galaxy and redshift
  86. VLA upper limit on INTEGRAL burst GRB 080613A
  87. GRB 0800603A: optical observation
  88. GRB080613B: MITSuME upper limits
  89. GRB080613A: Optical upper limits with Okayama MITSuME telescope
  90. Konus-Wind observation of GRB 080613B
  91. GRB 080603A: optical observations on June 04
  92. GRB 080613A: Swift-XRT detection of the afterglow
  93. GRB080613A: Swift/UVOT Upper Limits
  94. GRB 080613A: GROND Confirmation of the Afterglow Candidate
  95. GRB 080613B: GROND Upper Limits
  96. GRB 080613B - NOT optical and IR nondetections
  97. GRB080613B: Swift/UVOT Upper Limits
  98. GRB 080613B, Swift-BAT refined analysis
  99. GRB 080613B: Swift-XRT refined analysis
  100. GRB 080514B: Spectroscopic constraints and probable host galaxy

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