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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 080603B - TLS 2nd Epoch: Another Break
  2. GRB 080605: TLS 3rd Epoch - Source Confusion
  3. GRB080605: optical observation with the MITSuME-OAO telescope
  4. Konus-Wind observation of GRB 080607
  5. GRB080607: RTT150 optical observations
  6. GRB 080603A: optical observations
  7. GRB 080607: Swift-XRT refined analysis
  8. Swift/UVOT Observations of GRB080607
  9. GRB 080605: optical observations
  10. GRB 080607 KAIT observations
  11. VLA detection of INTEGRAL burst GRB 080603A
  12. Konus-Wind observation of GRB 080605
  13. GRB 080607: Enhanced Swift-XRT position
  14. GRB 080607, Swift-BAT refined analysis
  15. GRB 080605: GROND 2nd epoch observations
  16. GRB 080607 - PAIRITEL NIR detection
  17. GRB 080607: Keck/LRIS spectroscopy and redshift
  18. GRB 080607: Super-LOTIS early observations
  19. GRB 080607: Swift detection of a burst with optical afterglow
  20. GRB 080607: ROTSE-III Detection of Optical Counterpart
  21. GRB 080605: TLS RRM Analysis, Plateau/Rebrightening, Red OT
  22. GRB 080605: Swift-UVOT refined analysis
  23. Possible VLA radio detection on INTEGRAL burst GRB 080603A
  24. GRB 080604: VLA radio upper limit
  25. GRB 080605, Swift-BAT refined analysis
  26. GRB 080603B: VLA radio upper limit
  27. GRB 080605, Swift-BAT refined analysis
  28. GRB 080605: Swift-XRT refined analysis
  29. GRB080605: observation by BOOTES
  30. GRB 080605: MASTER VWF 46 s AT observation
  31. GRB 080605: Enhanced Swift-XRT position
  32. GRB 080605: GROND detection of the optical afterglow candidate
  33. GRB080605: optical observations
  34. GRB 080605: VLT redshift
  35. GRB 080605: Liverpool Telescope optical afterglow candidate
  36. GRB 080605: Swift/UVOT Position of the Optical Afterglow
  37. GRB 080605: TLS RRM Afterglow
  38. GRB 080605: Swift detection of a burst with an optical afterglow
  39. GRB 080603B: PAIRITEL infrared detection
  40. GRB 080603A: PAIRITEL infrared detection
  41. GRB 080604: Xinglong R band observation
  42. GRB 080603A: Xinglong R band observation
  43. GRB 080603B: TLS Afterglow Observation
  44. GRB 080603A: TLS Afterglow Observation
  45. GRB 080604: MITSuME Okayama observation
  46. Swift/UVOT observations of GRB080604
  47. GRB080604: HET redshift retraction
  48. GRB 080604: Gemini-North spectroscopy
  49. GRB 080604, Swift-BAT refined analysis
  50. GRB 080604: Swift-XRT refined analysis
  51. GRB 080603B: Hobby-Eberly Telescope redshift confirmation
  52. GRB 080603B : Xinglong EST observations
  53. GRB 080603B : Liverpool Telescope Observations
  54. Konus-Wind observation of GRB 080603B
  55. GRB 080603B: Swift-XRT refined analysis
  56. GRB 080603A: Swift-XRT detection of the afterglow
  57. GRB 080430: optical observations
  58. GRB 080603B: Swift/UVOT detection of the afterglow
  59. GRB 080604: Enhanced Swift-XRT position
  60. GRB 080603B, Swift-BAT refined analysis
  61. GRB 080604: Hobby-Eberly Telescope spectroscopy
  62. GRB 080603A: Swift/UVOT detection of the afterglow
  63. GRB080603B: RTT150 optical observations, break in light curves
  64. GRB 080604: Early Super-LOTIS Observations
  65. GRB080604: confirmation of optical afterglow
  66. GRB 080604: Swift detection of a burst with an optical afterglow
  67. GRB 080603B: TAROT Calern observatory confirmation of slow optical decay
  68. GRB 080516: TAROT La Silla observatory optical observations
  69. GRB080603B: NOT redshift
  70. GRB 080603B: BOOTES2/TELMA optical observations
  71. GRB 080603B: TAROT Calern observatory detection of a plateau in the light curve
  72. GRB 080603B: Swift detection of a burst with optical afterglow
  73. GRB080603: Super-LOTIS detection of Optical Counterpart
  74. GRB 080603B: ROTSE-III Detection of Optical Counterpart
  75. GRB 080603: Gemini-North redshift
  76. GRB 080603: A long GRB detected by INTEGRAL
  77. GRB 080603 OA candidate
  78. Possible GRB080603: Faulkes Telescope North optical afterglow candidate
  79. SGR 1627-41: Chandra/RXTE/Swift Observations Scheduled
  80. GRB 080602, Swift-BAT refined analysis
  81. GRB 080602: Swift-XRT refined analysis
  82. Konus-Wind observation of GRB 080602
  83. GRB 080602: NOT R-band upper limit
  84. GRB 080602: Enhanced Swift-XRT position
  85. GRB 080602: Swift detection of a burst
  86. Swift analysis of BAT Slew Survey event (Trigger=009)
  87. GRB 080523: afterglow confirmation and redshift constraints
  88. Konus-Wind observation of reactivation of SGR 1627-41
  89. Reactivation of SGR 1627-41
  90. GRB 080524: Swift XRT and UVOT analysis
  91. GRB 080503: 2nd Epoch Chandra X-ray Observations
  92. GRB 080524: Swift-BAT detection of a burst in ground analysis
  93. GRB 080523: Swift-XRT refined analysis
  94. GRB 080523, Swift-BAT refined analysis
  95. GRB 080520: VLT host detection
  96. GRB 080523: VLT optical observations
  97. Swift/UVOT observations of GRB 080523
  98. GRB 080523: Enhanced Swift-XRT position
  99. GRB 080523: Swift detection of a burst
  100. GRB 080515: NIR magnitude correction

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