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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. GRB080607: RTT150 optical observations
  2. GRB 080603A: optical observations
  3. GRB 080607: Swift-XRT refined analysis
  4. Swift/UVOT Observations of GRB080607
  5. GRB 080605: optical observations
  6. GRB 080607 KAIT observations
  7. VLA detection of INTEGRAL burst GRB 080603A
  8. Konus-Wind observation of GRB 080605
  9. GRB 080607: Enhanced Swift-XRT position
  10. GRB 080607, Swift-BAT refined analysis
  11. GRB 080605: GROND 2nd epoch observations
  12. GRB 080607 - PAIRITEL NIR detection
  13. GRB 080607: Keck/LRIS spectroscopy and redshift
  14. GRB 080607: Super-LOTIS early observations
  15. GRB 080607: Swift detection of a burst with optical afterglow
  16. GRB 080607: ROTSE-III Detection of Optical Counterpart
  17. GRB 080605: TLS RRM Analysis, Plateau/Rebrightening, Red OT
  18. GRB 080605: Swift-UVOT refined analysis
  19. Possible VLA radio detection on INTEGRAL burst GRB 080603A
  20. GRB 080604: VLA radio upper limit
  21. GRB 080605, Swift-BAT refined analysis
  22. GRB 080603B: VLA radio upper limit
  23. GRB 080605, Swift-BAT refined analysis
  24. GRB 080605: Swift-XRT refined analysis
  25. GRB080605: observation by BOOTES
  26. GRB 080605: MASTER VWF 46 s AT observation
  27. GRB 080605: Enhanced Swift-XRT position
  28. GRB 080605: GROND detection of the optical afterglow candidate
  29. GRB080605: optical observations
  30. GRB 080605: VLT redshift
  31. GRB 080605: Liverpool Telescope optical afterglow candidate
  32. GRB 080605: Swift/UVOT Position of the Optical Afterglow
  33. GRB 080605: TLS RRM Afterglow
  34. GRB 080605: Swift detection of a burst with an optical afterglow
  35. GRB 080603B: PAIRITEL infrared detection
  36. GRB 080603A: PAIRITEL infrared detection
  37. GRB 080604: Xinglong R band observation
  38. GRB 080603A: Xinglong R band observation
  39. GRB 080603B: TLS Afterglow Observation
  40. GRB 080603A: TLS Afterglow Observation
  41. GRB 080604: MITSuME Okayama observation
  42. Swift/UVOT observations of GRB080604
  43. GRB080604: HET redshift retraction
  44. GRB 080604: Gemini-North spectroscopy
  45. GRB 080604, Swift-BAT refined analysis
  46. GRB 080604: Swift-XRT refined analysis
  47. GRB 080603B: Hobby-Eberly Telescope redshift confirmation
  48. GRB 080603B : Xinglong EST observations
  49. GRB 080603B : Liverpool Telescope Observations
  50. Konus-Wind observation of GRB 080603B
  51. GRB 080603B: Swift-XRT refined analysis
  52. GRB 080603A: Swift-XRT detection of the afterglow
  53. GRB 080430: optical observations
  54. GRB 080603B: Swift/UVOT detection of the afterglow
  55. GRB 080604: Enhanced Swift-XRT position
  56. GRB 080603B, Swift-BAT refined analysis
  57. GRB 080604: Hobby-Eberly Telescope spectroscopy
  58. GRB 080603A: Swift/UVOT detection of the afterglow
  59. GRB080603B: RTT150 optical observations, break in light curves
  60. GRB 080604: Early Super-LOTIS Observations
  61. GRB080604: confirmation of optical afterglow
  62. GRB 080604: Swift detection of a burst with an optical afterglow
  63. GRB 080603B: TAROT Calern observatory confirmation of slow optical decay
  64. GRB 080516: TAROT La Silla observatory optical observations
  65. GRB080603B: NOT redshift
  66. GRB 080603B: BOOTES2/TELMA optical observations
  67. GRB 080603B: TAROT Calern observatory detection of a plateau in the light curve
  68. GRB 080603B: Swift detection of a burst with optical afterglow
  69. GRB080603: Super-LOTIS detection of Optical Counterpart
  70. GRB 080603B: ROTSE-III Detection of Optical Counterpart
  71. GRB 080603: Gemini-North redshift
  72. GRB 080603: A long GRB detected by INTEGRAL
  73. GRB 080603 OA candidate
  74. Possible GRB080603: Faulkes Telescope North optical afterglow candidate
  75. SGR 1627-41: Chandra/RXTE/Swift Observations Scheduled
  76. GRB 080602, Swift-BAT refined analysis
  77. GRB 080602: Swift-XRT refined analysis
  78. Konus-Wind observation of GRB 080602
  79. GRB 080602: NOT R-band upper limit
  80. GRB 080602: Enhanced Swift-XRT position
  81. GRB 080602: Swift detection of a burst
  82. Swift analysis of BAT Slew Survey event (Trigger=009)
  83. GRB 080523: afterglow confirmation and redshift constraints
  84. Konus-Wind observation of reactivation of SGR 1627-41
  85. Reactivation of SGR 1627-41
  86. GRB 080524: Swift XRT and UVOT analysis
  87. GRB 080503: 2nd Epoch Chandra X-ray Observations
  88. GRB 080524: Swift-BAT detection of a burst in ground analysis
  89. GRB 080523: Swift-XRT refined analysis
  90. GRB 080523, Swift-BAT refined analysis
  91. GRB 080520: VLT host detection
  92. GRB 080523: VLT optical observations
  93. Swift/UVOT observations of GRB 080523
  94. GRB 080523: Enhanced Swift-XRT position
  95. GRB 080523: Swift detection of a burst
  96. GRB 080515: NIR magnitude correction
  97. GRB 080515: KPNO 4m NIR afterglow detection
  98. GRB080521(?): detection of possible burst from BAT slew data and XRT ToO
  99. GRB 80516: Swift/UVOT Observations
  100. GRB 080515: Swift-XRT position and analysis

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