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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: Gemini spectroscopy and probable redshift
  2. UVOT white band observations of GRB080710
  3. GRB 080710: REM afterglow confirmation & brightening
  4. GRB 080710: KAIT OA candidate
  5. GRB 080710: Swift XRT position
  6. GRB 080710: Swift detection of a burst
  7. GRB 080707: possible break in the X-rays
  8. New Swift-XRT GRB products available online.
  9. GRB 080707: GROND Confirmation of the Optical Afterglow
  10. UVOT observations of GRB080707
  11. GRB 080707, Swift-BAT refined analysis
  12. GRB 080707: Swift XRT refined analysis
  13. GRB 080707: Enhanced Swift-XRT position
  14. GRB 080707: VLT redshift
  15. GRB 080707: GROND Detection of the Optical Afterglow Candidate
  16. GRB 080707: Swift detection of a burst
  17. Refined analysis of Swift Trigger 316063, is IGR J08408-4503
  18. Trigger 316063: Swift detection of a transient
  19. GRB 080703: GROND Upper Limits
  20. GRB 080702B: GROND Upper Limits
  21. GRB 080703: Swift-XRT refined analysis
  22. GRB 080703: UVOT Follow-Up Observation
  23. GRB 080703: VLT observations of the afterglow
  24. GRB 080703: Enhanced Swift-XRT position
  25. GRB 080703, Swift-BAT refined analysis
  26. GRB 080702B Swift-BAT refined analysis
  27. GRB 080703: Swift detection of a burst with optical afterglow
  28. GRB 080703A: ROTSE-III Detection of Optical Counterpart
  29. No radio detection from the short GRB 080702A
  30. GRB 080702b: LCO optical observations
  31. Swift/UVOT observation of GRB080702A
  32. GRB 080702B: Swift XRT and UVOT observations
  33. GRB 080625: Suzaku WAM observation of the prompt emission
  34. GRB 080702A: MITSuME Akeno optical upper limits
  35. GRB 080701A: Early RAPTOR optical limits
  36. Swift Trigger 315630: Swift/UVOT Upper Limits
  37. GRB 080702A, Swift-BAT refined analysis
  38. GRB 080702A: Swift-XRT Team refined analysis
  39. GRB 080702B : Burst detected in BAT during Swift slew
  40. GRB 080702A: Enhanced Swift-XRT position
  41. Swift Trigger 315630: TLS R-band observation
  42. Swift Trigger 315630: Probably not a GRB
  43. GRB 080702: Swift detection of a short burst
  44. GRB 080701: Swift-XRT refined analysis
  45. GRB 080701A, VATT optical upper limit
  46. TLS I-Band Observation of GRB 080701A
  47. GRB 080701A: Swift/UVOT Upper Limits
  48. GRB 080701A: Early Super-LOTIS Observations
  49. GRB 080701: Enhanced Swift-XRT position
  50. GRB 080701A, Swift-BAT refined analysis
  51. Trigger 315630: Swift detection of a possible burst
  52. GRB 080701: Swift-XRT Prompt Analysis
  53. GRB 080701: Swift detection of a burst
  54. GRB 080623: Suzaku WAM observation of the prompt emission
  55. GRB 080625: Swift/UVOT Follow-Up Observations
  56. GRB 080625: Further observations from OSN
  57. GRB 080625:Swift-XRT detection of the afterglow
  58. GRB 080625: Swift/UVOT Detection of an Optical Afterglow
  59. GRB 080625: Observations at OSN
  60. GRB 080625: Gamma Ray Burst Localization by SuperAGILE
  61. GRB 080623: GROND upper limits
  62. GRB080623: Swift UVOT followup observations
  63. GRB 080623: Swift-XRT refined analysis
  64. GRB 080623, Swift-BAT refined analysis
  65. GRB 080623: Enhanced Swift-XRT position
  66. GRB 080623: TAROT La Silla observatory optical observations
  67. GRB 080623: Swift/UVOT Non-Detection of an Optical Afterglow
  68. GRB 080623: Swift XRT prompt analysis
  69. GRB 080623: Swift detection of a burst
  70. Swift trigger 314975 is not a GRB
  71. Swift-BAT trigger 314975 possible burst
  72. GRB080607: optical observation
  73. GRB 080603b: optical observation
  74. GRB 070809: Putative host galaxy and redshift
  75. VLA upper limit on INTEGRAL burst GRB 080613A
  76. GRB 0800603A: optical observation
  77. GRB080613B: MITSuME upper limits
  78. GRB080613A: Optical upper limits with Okayama MITSuME telescope
  79. Konus-Wind observation of GRB 080613B
  80. GRB 080603A: optical observations on June 04
  81. GRB 080613A: Swift-XRT detection of the afterglow
  82. GRB080613A: Swift/UVOT Upper Limits
  83. GRB 080613A: GROND Confirmation of the Afterglow Candidate
  84. GRB 080613B: GROND Upper Limits
  85. GRB 080613B - NOT optical and IR nondetections
  86. GRB080613B: Swift/UVOT Upper Limits
  87. GRB 080613B, Swift-BAT refined analysis
  88. GRB 080613B: Swift-XRT refined analysis
  89. GRB 080514B: Spectroscopic constraints and probable host galaxy
  90. GRB 080613B: Swift detection of a burst
  91. GRB 080613: Faulkes Telescope North optical candidate
  92. GRB 080613 : a long GRB detected with INTEGRAL
  93. GRB 080603A: Late-time Keck imaging and spectroscopy
  94. GRB 080603b: optical observation
  95. Swift observations of BAT Slew Survey event (Trigger=010)
  96. GRB 080603A: final Swift-XRT observations.
  97. GRB 080607: AGILE-MCAL observation of the prompt emission
  98. GRB 080603B - TLS 2nd Epoch: Another Break
  99. GRB 080605: TLS 3rd Epoch - Source Confusion
  100. GRB080605: optical observation with the MITSuME-OAO telescope

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