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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 080307 : BOAO optical afterglow observation
  2. GRB 080307: Optical observation with DMC/KANATA
  3. GRB 080307: Swift detection of a burst
  4. VLA possible radio detection of GRB 080229
  5. GRB 080303: Swift/UVOT follow-up of afterglow detection
  6. GRB 080303, Swift-BAT refined analysis
  7. GRB 080303: Rapid PROMPT Detections
  8. GRB080303: Swift XRT refined analysis
  9. GRB 080303: Enhanced Swift-XRT position
  10. Swift UVOT observations of GRB080229B
  11. GRB080229B: Swift XRT afterglow observation
  12. GRB 080303A: Faulkes Telescope South optical afterglow observations
  13. GRB 080303
  14. GRB 080303: Swift detection of a burst with optical afterglow
  15. GRB 080303: REM NIR afterglow candidate
  16. GRB 080303A: ROTSE-III Optical Limits
  17. GRB 080229: I-band observations from OSN
  18. GRB 080229: VLT NIR observations
  19. GRB080229: Swift XRT refined analysis
  20. GRB 080229: TNG NIR observations
  21. GRB 080229: Deep Gemini/GMOS optical observations
  22. GRB 080229: Enhanced Swift-XRT position
  23. GRB 080229: REM NIR observations
  24. GRB080229: Possible optical afterglow
  25. GRB 080229B: Gamma Ray Burst Localization by SuperAGILE
  26. UVOT analysis for GRB080229
  27. GRB 080229, Swift-BAT refined analysis
  28. GRB 080229: Faulkes Telescope South optical limit
  29. GRB 080229A: ROTSE-III Optical Limits
  30. GRB 080229: Swift detection of a bright burst
  31. Early optical shallow decay in GRB 071112C
  32. GRB080207: optical observations
  33. GRB080205: optical observations
  34. GRB080211: optical observations
  35. XRF 080109/SN2008D : GMRT upper limit at 1.28 GHz
  36. GRB 071010B : Early optical brightening detected by TAOS
  37. Swift-XRT improved positions, and new redshift limits.
  38. ESO optical and NIR observations of GRB 080218B
  39. GRB 080204: Suzaku WAM observation of the prompt emission
  40. GRB 080218B, Swift-BAT refined analysis
  41. GRB 080218B: Swift-XRT refined analysis
  42. Swift/UVOT observations of GRB080218B
  43. GRB 080218B: REM NIR early upper limits
  44. GRB 080212: Mount Abu NIR observations
  45. GRB 080218B: Enhanced Swift-XRT position
  46. GRB 080218B: GROND upper limits
  47. GRB 080218b, SMARTS optical/IR limits
  48. GRB 080218A, Swift-BAT refined analysis
  49. GRB080218B: Watcher prompt limit
  50. GRB 080211: Suzaku WAM observation of the prompt emission
  51. GRB 080218B: Swift detection of a burst
  52. GRB 080218: Swift detection of a burst
  53. Swift-XRT and UVOT observations of the IPN burst GRB 080211
  54. GRB 080212: VLT optical rapid decay
  55. GRB 080212: REM refined analysis
  56. Konus-Wind observation of GRB 080211
  57. VLA radio upper limit on GRB 080212
  58. Swift/UVOT refined analysis of GRB080212
  59. GRB 080212, Swift-BAT refined analysis
  60. GRB080212: Optical afterglow candidate observed by MITSuME Telescope
  61. GRB 080212: Gemini-South optical observations
  62. GRB 080212: GROND detects afterglow
  63. GRB 080212: REM NIR afterglow?
  64. GRB 080212: optical observations
  65. GRB 080212: Enhanced Swift-XRT position
  66. GRB 080212: Swift-XRT Team refined analysis
  67. GRB 080210: Keck photometry
  68. VLA non-detection of GRB 080210
  69. GRB 080212: Swift detection of a burst
  70. IPN localization of GRB 080211
  71. GRB 080212: DSS/2MASS Galaxy at XRT position
  72. GRB 080207: VLT NIR early upper limits
  73. GRB 080210: Swift/UVOT Refined Analysis
  74. GRB 080207: optical observations.
  75. GRB 080210: Hobby-Eberly Telescope Absorption Spectroscopy
  76. GRB 080210, Swift-BAT refined analysis
  77. GRB 080210: Super-LOTIS observations
  78. GRB 080210: Swift-XRT Refined Analysis
  79. GRB 080210: VLT redshift
  80. GRB 080210: Enhanced Swift-XRT position
  81. GRB 080210: Rapid PROMPT Detections
  82. GRB 080210: GOND detection in all bands and redshift upper limit
  83. GRB080210 - SDSS Pre-Burst Observations
  84. GRB 080210: Swift detection of a burst with optical afterglow
  85. GRB 080210: TAROT La Silla observatory optical detection
  86. GRB 080207: GROND upper limits
  87. GRB 080205: GAO 150cm telescope Optical limit
  88. GRB 080207, Swift-BAT refined analysis
  89. GRB 080207: Optical limits from Gemini-South
  90. GRB 080205: RTT150 optical observations
  91. Swift detection of AX J1749.1-2639
  92. GRB 080207: Super-LOTIS observations
  93. GRB 080207, Swift-BAT refined analysis
  94. Swift Trigger 302777 is not a GRB
  95. GRB080207: RTT150 Optical Observations
  96. GRB 080207: REM NIR observations
  97. GRB080207: Swift/UVOT refined analysis
  98. GRB 080207: TAROT Calern observatory optical observations
  99. GRB 080207: Swift-XRT Refined Analysis
  100. GRB 080207: Enhanced Swift-XRT position

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