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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. GRB080605: observation by BOOTES
  2. GRB 080605: MASTER VWF 46 s AT observation
  3. GRB 080605: Enhanced Swift-XRT position
  4. GRB 080605: GROND detection of the optical afterglow candidate
  5. GRB080605: optical observations
  6. GRB 080605: VLT redshift
  7. GRB 080605: Liverpool Telescope optical afterglow candidate
  8. GRB 080605: Swift/UVOT Position of the Optical Afterglow
  9. GRB 080605: TLS RRM Afterglow
  10. GRB 080605: Swift detection of a burst with an optical afterglow
  11. GRB 080603B: PAIRITEL infrared detection
  12. GRB 080603A: PAIRITEL infrared detection
  13. GRB 080604: Xinglong R band observation
  14. GRB 080603A: Xinglong R band observation
  15. GRB 080603B: TLS Afterglow Observation
  16. GRB 080603A: TLS Afterglow Observation
  17. GRB 080604: MITSuME Okayama observation
  18. Swift/UVOT observations of GRB080604
  19. GRB080604: HET redshift retraction
  20. GRB 080604: Gemini-North spectroscopy
  21. GRB 080604, Swift-BAT refined analysis
  22. GRB 080604: Swift-XRT refined analysis
  23. GRB 080603B: Hobby-Eberly Telescope redshift confirmation
  24. GRB 080603B : Xinglong EST observations
  25. GRB 080603B : Liverpool Telescope Observations
  26. Konus-Wind observation of GRB 080603B
  27. GRB 080603B: Swift-XRT refined analysis
  28. GRB 080603A: Swift-XRT detection of the afterglow
  29. GRB 080430: optical observations
  30. GRB 080603B: Swift/UVOT detection of the afterglow
  31. GRB 080604: Enhanced Swift-XRT position
  32. GRB 080603B, Swift-BAT refined analysis
  33. GRB 080604: Hobby-Eberly Telescope spectroscopy
  34. GRB 080603A: Swift/UVOT detection of the afterglow
  35. GRB080603B: RTT150 optical observations, break in light curves
  36. GRB 080604: Early Super-LOTIS Observations
  37. GRB080604: confirmation of optical afterglow
  38. GRB 080604: Swift detection of a burst with an optical afterglow
  39. GRB 080603B: TAROT Calern observatory confirmation of slow optical decay
  40. GRB 080516: TAROT La Silla observatory optical observations
  41. GRB080603B: NOT redshift
  42. GRB 080603B: BOOTES2/TELMA optical observations
  43. GRB 080603B: TAROT Calern observatory detection of a plateau in the light curve
  44. GRB 080603B: Swift detection of a burst with optical afterglow
  45. GRB080603: Super-LOTIS detection of Optical Counterpart
  46. GRB 080603B: ROTSE-III Detection of Optical Counterpart
  47. GRB 080603: Gemini-North redshift
  48. GRB 080603: A long GRB detected by INTEGRAL
  49. GRB 080603 OA candidate
  50. Possible GRB080603: Faulkes Telescope North optical afterglow candidate
  51. SGR 1627-41: Chandra/RXTE/Swift Observations Scheduled
  52. GRB 080602, Swift-BAT refined analysis
  53. GRB 080602: Swift-XRT refined analysis
  54. Konus-Wind observation of GRB 080602
  55. GRB 080602: NOT R-band upper limit
  56. GRB 080602: Enhanced Swift-XRT position
  57. GRB 080602: Swift detection of a burst
  58. Swift analysis of BAT Slew Survey event (Trigger=009)
  59. GRB 080523: afterglow confirmation and redshift constraints
  60. Konus-Wind observation of reactivation of SGR 1627-41
  61. Reactivation of SGR 1627-41
  62. GRB 080524: Swift XRT and UVOT analysis
  63. GRB 080503: 2nd Epoch Chandra X-ray Observations
  64. GRB 080524: Swift-BAT detection of a burst in ground analysis
  65. GRB 080523: Swift-XRT refined analysis
  66. GRB 080523, Swift-BAT refined analysis
  67. GRB 080520: VLT host detection
  68. GRB 080523: VLT optical observations
  69. Swift/UVOT observations of GRB 080523
  70. GRB 080523: Enhanced Swift-XRT position
  71. GRB 080523: Swift detection of a burst
  72. GRB 080515: NIR magnitude correction
  73. GRB 080515: KPNO 4m NIR afterglow detection
  74. GRB080521(?): detection of possible burst from BAT slew data and XRT ToO
  75. GRB 80516: Swift/UVOT Observations
  76. GRB 080515: Swift-XRT position and analysis
  77. GRB 080520, Swift-BAT refined analysis
  78. GRB 080514B: pseudo-z= 1.8 from prompt emission spectrum
  79. GRB 080514B: UVOT Observations
  80. GRB080520: Swift/UVOT observations
  81. GRB 080520: VLT redshift
  82. GRB 080520, GROND observations
  83. GRB 080520: Enhanced Swift-XRT position
  84. GRB 080520: Swift XRT Refined Analysis
  85. GRB 080520: Swift detection of a burst with optical afterglow
  86. GRB 080514B: Suzaku WAM observation of the prompt emission
  87. Konus-Wind observation of GRB 080514B
  88. GRB 080514B: second epoch Swift XRT data confirms the X-ray afterglow
  89. GRB 080503: Further HST imaging
  90. GRB 080517, Swift-BAT refined analysis
  91. GRB 080516, GROND further analysis
  92. GRB 080517: Swift-XRT refined analysis
  93. GRB 080514B: Further NIR observations
  94. GRB 080517: Enhanced Swift-XRT position
  95. GRB080517: Liverpool Telescope Optical Observations
  96. GRB 080517: Swift detection of a burst
  97. GRB 080516, GROND 2nd epoch observations
  98. GRB 080516, GROND observations
  99. GRB080430: optical observations
  100. GRB 080516, SMARTS optical/IR observations

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