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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: Rapid PROMPT Observations
  2. GRB 080710: Swift-XRT refined analysis
  3. GRB080710: Swift/UVOT observations
  4. GRB 080710: Enhanced Swift-XRT position
  5. GRB 080710: Faulkes Telescope North observations
  6. GRB 080710: Gemini spectroscopy and probable redshift
  7. UVOT white band observations of GRB080710
  8. GRB 080710: REM afterglow confirmation & brightening
  9. GRB 080710: KAIT OA candidate
  10. GRB 080710: Swift XRT position
  11. GRB 080710: Swift detection of a burst
  12. GRB 080707: possible break in the X-rays
  13. New Swift-XRT GRB products available online.
  14. GRB 080707: GROND Confirmation of the Optical Afterglow
  15. UVOT observations of GRB080707
  16. GRB 080707, Swift-BAT refined analysis
  17. GRB 080707: Swift XRT refined analysis
  18. GRB 080707: Enhanced Swift-XRT position
  19. GRB 080707: VLT redshift
  20. GRB 080707: GROND Detection of the Optical Afterglow Candidate
  21. GRB 080707: Swift detection of a burst
  22. Refined analysis of Swift Trigger 316063, is IGR J08408-4503
  23. Trigger 316063: Swift detection of a transient
  24. GRB 080703: GROND Upper Limits
  25. GRB 080702B: GROND Upper Limits
  26. GRB 080703: Swift-XRT refined analysis
  27. GRB 080703: UVOT Follow-Up Observation
  28. GRB 080703: VLT observations of the afterglow
  29. GRB 080703: Enhanced Swift-XRT position
  30. GRB 080703, Swift-BAT refined analysis
  31. GRB 080702B Swift-BAT refined analysis
  32. GRB 080703: Swift detection of a burst with optical afterglow
  33. GRB 080703A: ROTSE-III Detection of Optical Counterpart
  34. No radio detection from the short GRB 080702A
  35. GRB 080702b: LCO optical observations
  36. Swift/UVOT observation of GRB080702A
  37. GRB 080702B: Swift XRT and UVOT observations
  38. GRB 080625: Suzaku WAM observation of the prompt emission
  39. GRB 080702A: MITSuME Akeno optical upper limits
  40. GRB 080701A: Early RAPTOR optical limits
  41. Swift Trigger 315630: Swift/UVOT Upper Limits
  42. GRB 080702A, Swift-BAT refined analysis
  43. GRB 080702A: Swift-XRT Team refined analysis
  44. GRB 080702B : Burst detected in BAT during Swift slew
  45. GRB 080702A: Enhanced Swift-XRT position
  46. Swift Trigger 315630: TLS R-band observation
  47. Swift Trigger 315630: Probably not a GRB
  48. GRB 080702: Swift detection of a short burst
  49. GRB 080701: Swift-XRT refined analysis
  50. GRB 080701A, VATT optical upper limit
  51. TLS I-Band Observation of GRB 080701A
  52. GRB 080701A: Swift/UVOT Upper Limits
  53. GRB 080701A: Early Super-LOTIS Observations
  54. GRB 080701: Enhanced Swift-XRT position
  55. GRB 080701A, Swift-BAT refined analysis
  56. Trigger 315630: Swift detection of a possible burst
  57. GRB 080701: Swift-XRT Prompt Analysis
  58. GRB 080701: Swift detection of a burst
  59. GRB 080623: Suzaku WAM observation of the prompt emission
  60. GRB 080625: Swift/UVOT Follow-Up Observations
  61. GRB 080625: Further observations from OSN
  62. GRB 080625:Swift-XRT detection of the afterglow
  63. GRB 080625: Swift/UVOT Detection of an Optical Afterglow
  64. GRB 080625: Observations at OSN
  65. GRB 080625: Gamma Ray Burst Localization by SuperAGILE
  66. GRB 080623: GROND upper limits
  67. GRB080623: Swift UVOT followup observations
  68. GRB 080623: Swift-XRT refined analysis
  69. GRB 080623, Swift-BAT refined analysis
  70. GRB 080623: Enhanced Swift-XRT position
  71. GRB 080623: TAROT La Silla observatory optical observations
  72. GRB 080623: Swift/UVOT Non-Detection of an Optical Afterglow
  73. GRB 080623: Swift XRT prompt analysis
  74. GRB 080623: Swift detection of a burst
  75. Swift trigger 314975 is not a GRB
  76. Swift-BAT trigger 314975 possible burst
  77. GRB080607: optical observation
  78. GRB 080603b: optical observation
  79. GRB 070809: Putative host galaxy and redshift
  80. VLA upper limit on INTEGRAL burst GRB 080613A
  81. GRB 0800603A: optical observation
  82. GRB080613B: MITSuME upper limits
  83. GRB080613A: Optical upper limits with Okayama MITSuME telescope
  84. Konus-Wind observation of GRB 080613B
  85. GRB 080603A: optical observations on June 04
  86. GRB 080613A: Swift-XRT detection of the afterglow
  87. GRB080613A: Swift/UVOT Upper Limits
  88. GRB 080613A: GROND Confirmation of the Afterglow Candidate
  89. GRB 080613B: GROND Upper Limits
  90. GRB 080613B - NOT optical and IR nondetections
  91. GRB080613B: Swift/UVOT Upper Limits
  92. GRB 080613B, Swift-BAT refined analysis
  93. GRB 080613B: Swift-XRT refined analysis
  94. GRB 080514B: Spectroscopic constraints and probable host galaxy
  95. GRB 080613B: Swift detection of a burst
  96. GRB 080613: Faulkes Telescope North optical candidate
  97. GRB 080613 : a long GRB detected with INTEGRAL
  98. GRB 080603A: Late-time Keck imaging and spectroscopy
  99. GRB 080603b: optical observation
  100. Swift observations of BAT Slew Survey event (Trigger=010)

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