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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: VLA radio upper limit
  2. GRB 080605, Swift-BAT refined analysis
  3. GRB 080605: Swift-XRT refined analysis
  4. GRB080605: observation by BOOTES
  5. GRB 080605: MASTER VWF 46 s AT observation
  6. GRB 080605: Enhanced Swift-XRT position
  7. GRB 080605: GROND detection of the optical afterglow candidate
  8. GRB080605: optical observations
  9. GRB 080605: VLT redshift
  10. GRB 080605: Liverpool Telescope optical afterglow candidate
  11. GRB 080605: Swift/UVOT Position of the Optical Afterglow
  12. GRB 080605: TLS RRM Afterglow
  13. GRB 080605: Swift detection of a burst with an optical afterglow
  14. GRB 080603B: PAIRITEL infrared detection
  15. GRB 080603A: PAIRITEL infrared detection
  16. GRB 080604: Xinglong R band observation
  17. GRB 080603A: Xinglong R band observation
  18. GRB 080603B: TLS Afterglow Observation
  19. GRB 080603A: TLS Afterglow Observation
  20. GRB 080604: MITSuME Okayama observation
  21. Swift/UVOT observations of GRB080604
  22. GRB080604: HET redshift retraction
  23. GRB 080604: Gemini-North spectroscopy
  24. GRB 080604, Swift-BAT refined analysis
  25. GRB 080604: Swift-XRT refined analysis
  26. GRB 080603B: Hobby-Eberly Telescope redshift confirmation
  27. GRB 080603B : Xinglong EST observations
  28. GRB 080603B : Liverpool Telescope Observations
  29. Konus-Wind observation of GRB 080603B
  30. GRB 080603B: Swift-XRT refined analysis
  31. GRB 080603A: Swift-XRT detection of the afterglow
  32. GRB 080430: optical observations
  33. GRB 080603B: Swift/UVOT detection of the afterglow
  34. GRB 080604: Enhanced Swift-XRT position
  35. GRB 080603B, Swift-BAT refined analysis
  36. GRB 080604: Hobby-Eberly Telescope spectroscopy
  37. GRB 080603A: Swift/UVOT detection of the afterglow
  38. GRB080603B: RTT150 optical observations, break in light curves
  39. GRB 080604: Early Super-LOTIS Observations
  40. GRB080604: confirmation of optical afterglow
  41. GRB 080604: Swift detection of a burst with an optical afterglow
  42. GRB 080603B: TAROT Calern observatory confirmation of slow optical decay
  43. GRB 080516: TAROT La Silla observatory optical observations
  44. GRB080603B: NOT redshift
  45. GRB 080603B: BOOTES2/TELMA optical observations
  46. GRB 080603B: TAROT Calern observatory detection of a plateau in the light curve
  47. GRB 080603B: Swift detection of a burst with optical afterglow
  48. GRB080603: Super-LOTIS detection of Optical Counterpart
  49. GRB 080603B: ROTSE-III Detection of Optical Counterpart
  50. GRB 080603: Gemini-North redshift
  51. GRB 080603: A long GRB detected by INTEGRAL
  52. GRB 080603 OA candidate
  53. Possible GRB080603: Faulkes Telescope North optical afterglow candidate
  54. SGR 1627-41: Chandra/RXTE/Swift Observations Scheduled
  55. GRB 080602, Swift-BAT refined analysis
  56. GRB 080602: Swift-XRT refined analysis
  57. Konus-Wind observation of GRB 080602
  58. GRB 080602: NOT R-band upper limit
  59. GRB 080602: Enhanced Swift-XRT position
  60. GRB 080602: Swift detection of a burst
  61. Swift analysis of BAT Slew Survey event (Trigger=009)
  62. GRB 080523: afterglow confirmation and redshift constraints
  63. Konus-Wind observation of reactivation of SGR 1627-41
  64. Reactivation of SGR 1627-41
  65. GRB 080524: Swift XRT and UVOT analysis
  66. GRB 080503: 2nd Epoch Chandra X-ray Observations
  67. GRB 080524: Swift-BAT detection of a burst in ground analysis
  68. GRB 080523: Swift-XRT refined analysis
  69. GRB 080523, Swift-BAT refined analysis
  70. GRB 080520: VLT host detection
  71. GRB 080523: VLT optical observations
  72. Swift/UVOT observations of GRB 080523
  73. GRB 080523: Enhanced Swift-XRT position
  74. GRB 080523: Swift detection of a burst
  75. GRB 080515: NIR magnitude correction
  76. GRB 080515: KPNO 4m NIR afterglow detection
  77. GRB080521(?): detection of possible burst from BAT slew data and XRT ToO
  78. GRB 80516: Swift/UVOT Observations
  79. GRB 080515: Swift-XRT position and analysis
  80. GRB 080520, Swift-BAT refined analysis
  81. GRB 080514B: pseudo-z= 1.8 from prompt emission spectrum
  82. GRB 080514B: UVOT Observations
  83. GRB080520: Swift/UVOT observations
  84. GRB 080520: VLT redshift
  85. GRB 080520, GROND observations
  86. GRB 080520: Enhanced Swift-XRT position
  87. GRB 080520: Swift XRT Refined Analysis
  88. GRB 080520: Swift detection of a burst with optical afterglow
  89. GRB 080514B: Suzaku WAM observation of the prompt emission
  90. Konus-Wind observation of GRB 080514B
  91. GRB 080514B: second epoch Swift XRT data confirms the X-ray afterglow
  92. GRB 080503: Further HST imaging
  93. GRB 080517, Swift-BAT refined analysis
  94. GRB 080516, GROND further analysis
  95. GRB 080517: Swift-XRT refined analysis
  96. GRB 080514B: Further NIR observations
  97. GRB 080517: Enhanced Swift-XRT position
  98. GRB080517: Liverpool Telescope Optical Observations
  99. GRB 080517: Swift detection of a burst
  100. GRB 080516, GROND 2nd epoch observations

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