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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: Swift-XRT refined analysis
  2. GRB 080603A: Swift-XRT detection of the afterglow
  3. GRB 080430: optical observations
  4. GRB 080603B: Swift/UVOT detection of the afterglow
  5. GRB 080604: Enhanced Swift-XRT position
  6. GRB 080603B, Swift-BAT refined analysis
  7. GRB 080604: Hobby-Eberly Telescope spectroscopy
  8. GRB 080603A: Swift/UVOT detection of the afterglow
  9. GRB080603B: RTT150 optical observations, break in light curves
  10. GRB 080604: Early Super-LOTIS Observations
  11. GRB080604: confirmation of optical afterglow
  12. GRB 080604: Swift detection of a burst with an optical afterglow
  13. GRB 080603B: TAROT Calern observatory confirmation of slow optical decay
  14. GRB 080516: TAROT La Silla observatory optical observations
  15. GRB080603B: NOT redshift
  16. GRB 080603B: BOOTES2/TELMA optical observations
  17. GRB 080603B: TAROT Calern observatory detection of a plateau in the light curve
  18. GRB 080603B: Swift detection of a burst with optical afterglow
  19. GRB080603: Super-LOTIS detection of Optical Counterpart
  20. GRB 080603B: ROTSE-III Detection of Optical Counterpart
  21. GRB 080603: Gemini-North redshift
  22. GRB 080603: A long GRB detected by INTEGRAL
  23. GRB 080603 OA candidate
  24. Possible GRB080603: Faulkes Telescope North optical afterglow candidate
  25. SGR 1627-41: Chandra/RXTE/Swift Observations Scheduled
  26. GRB 080602, Swift-BAT refined analysis
  27. GRB 080602: Swift-XRT refined analysis
  28. Konus-Wind observation of GRB 080602
  29. GRB 080602: NOT R-band upper limit
  30. GRB 080602: Enhanced Swift-XRT position
  31. GRB 080602: Swift detection of a burst
  32. Swift analysis of BAT Slew Survey event (Trigger=009)
  33. GRB 080523: afterglow confirmation and redshift constraints
  34. Konus-Wind observation of reactivation of SGR 1627-41
  35. Reactivation of SGR 1627-41
  36. GRB 080524: Swift XRT and UVOT analysis
  37. GRB 080503: 2nd Epoch Chandra X-ray Observations
  38. GRB 080524: Swift-BAT detection of a burst in ground analysis
  39. GRB 080523: Swift-XRT refined analysis
  40. GRB 080523, Swift-BAT refined analysis
  41. GRB 080520: VLT host detection
  42. GRB 080523: VLT optical observations
  43. Swift/UVOT observations of GRB 080523
  44. GRB 080523: Enhanced Swift-XRT position
  45. GRB 080523: Swift detection of a burst
  46. GRB 080515: NIR magnitude correction
  47. GRB 080515: KPNO 4m NIR afterglow detection
  48. GRB080521(?): detection of possible burst from BAT slew data and XRT ToO
  49. GRB 80516: Swift/UVOT Observations
  50. GRB 080515: Swift-XRT position and analysis
  51. GRB 080520, Swift-BAT refined analysis
  52. GRB 080514B: pseudo-z= 1.8 from prompt emission spectrum
  53. GRB 080514B: UVOT Observations
  54. GRB080520: Swift/UVOT observations
  55. GRB 080520: VLT redshift
  56. GRB 080520, GROND observations
  57. GRB 080520: Enhanced Swift-XRT position
  58. GRB 080520: Swift XRT Refined Analysis
  59. GRB 080520: Swift detection of a burst with optical afterglow
  60. GRB 080514B: Suzaku WAM observation of the prompt emission
  61. Konus-Wind observation of GRB 080514B
  62. GRB 080514B: second epoch Swift XRT data confirms the X-ray afterglow
  63. GRB 080503: Further HST imaging
  64. GRB 080517, Swift-BAT refined analysis
  65. GRB 080516, GROND further analysis
  66. GRB 080517: Swift-XRT refined analysis
  67. GRB 080514B: Further NIR observations
  68. GRB 080517: Enhanced Swift-XRT position
  69. GRB080517: Liverpool Telescope Optical Observations
  70. GRB 080517: Swift detection of a burst
  71. GRB 080516, GROND 2nd epoch observations
  72. GRB 080516, GROND observations
  73. GRB080430: optical observations
  74. GRB 080516, SMARTS optical/IR observations
  75. GRB 080516: Swift-XRT Team refined analysis
  76. GRB 080516, Swift-BAT refined analysis
  77. GRB 080516: Enhanced Swift-XRT position
  78. GRB 080514B: NOT observations
  79. GRB 080516: Swift detection of a burst
  80. Errartum: VLA upper limit on GRB 080507
  81. VLA upper limit on GRB 080705
  82. GRB 080514B : redshift estimation
  83. Konus-Wind observation of GRB 080513
  84. IPN triangulation of bright GRB 080513
  85. Swift-BAT refined analysis for Trigger 311603: Galactic source
  86. GRB 080515, Swift-BAT refined analysis
  87. GRB 080514B: KPNO 4m IR observations
  88. GRB 080514B: slow fading behaviour ?
  89. GRB 080514B: Swift-XRT analysis
  90. GRB 080514B, GROND observations
  91. GRB 080515: Swift detection of a burst
  92. GRB 080514B: Finding chart
  93. GRB 080514B: Afterglow candidate
  94. GRB 080514B: Watcher observations
  95. GRB 080430
  96. GRB 080514B: possible AGILE detection at E>50 MeV
  97. GRB 080514B: SuperAGILE/IPN GRB Localization
  98. procesure for GRB Circular
  99. Swift detection of a possible galactic transient
  100. GRB080514: REM NIR & Optical Observations

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