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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 080218B: Swift-XRT refined analysis
  2. Swift/UVOT observations of GRB080218B
  3. GRB 080218B: REM NIR early upper limits
  4. GRB 080212: Mount Abu NIR observations
  5. GRB 080218B: Enhanced Swift-XRT position
  6. GRB 080218B: GROND upper limits
  7. GRB 080218b, SMARTS optical/IR limits
  8. GRB 080218A, Swift-BAT refined analysis
  9. GRB080218B: Watcher prompt limit
  10. GRB 080211: Suzaku WAM observation of the prompt emission
  11. GRB 080218B: Swift detection of a burst
  12. GRB 080218: Swift detection of a burst
  13. Swift-XRT and UVOT observations of the IPN burst GRB 080211
  14. GRB 080212: VLT optical rapid decay
  15. GRB 080212: REM refined analysis
  16. Konus-Wind observation of GRB 080211
  17. VLA radio upper limit on GRB 080212
  18. Swift/UVOT refined analysis of GRB080212
  19. GRB 080212, Swift-BAT refined analysis
  20. GRB080212: Optical afterglow candidate observed by MITSuME Telescope
  21. GRB 080212: Gemini-South optical observations
  22. GRB 080212: GROND detects afterglow
  23. GRB 080212: REM NIR afterglow?
  24. GRB 080212: optical observations
  25. GRB 080212: Enhanced Swift-XRT position
  26. GRB 080212: Swift-XRT Team refined analysis
  27. GRB 080210: Keck photometry
  28. VLA non-detection of GRB 080210
  29. GRB 080212: Swift detection of a burst
  30. IPN localization of GRB 080211
  31. GRB 080212: DSS/2MASS Galaxy at XRT position
  32. GRB 080207: VLT NIR early upper limits
  33. GRB 080210: Swift/UVOT Refined Analysis
  34. GRB 080207: optical observations.
  35. GRB 080210: Hobby-Eberly Telescope Absorption Spectroscopy
  36. GRB 080210, Swift-BAT refined analysis
  37. GRB 080210: Super-LOTIS observations
  38. GRB 080210: Swift-XRT Refined Analysis
  39. GRB 080210: VLT redshift
  40. GRB 080210: Enhanced Swift-XRT position
  41. GRB 080210: Rapid PROMPT Detections
  42. GRB 080210: GOND detection in all bands and redshift upper limit
  43. GRB080210 - SDSS Pre-Burst Observations
  44. GRB 080210: Swift detection of a burst with optical afterglow
  45. GRB 080210: TAROT La Silla observatory optical detection
  46. GRB 080207: GROND upper limits
  47. GRB 080205: GAO 150cm telescope Optical limit
  48. GRB 080207, Swift-BAT refined analysis
  49. GRB 080207: Optical limits from Gemini-South
  50. GRB 080205: RTT150 optical observations
  51. Swift detection of AX J1749.1-2639
  52. GRB 080207: Super-LOTIS observations
  53. GRB 080207, Swift-BAT refined analysis
  54. Swift Trigger 302777 is not a GRB
  55. GRB080207: RTT150 Optical Observations
  56. GRB 080207: REM NIR observations
  57. GRB080207: Swift/UVOT refined analysis
  58. GRB 080207: TAROT Calern observatory optical observations
  59. GRB 080207: Swift-XRT Refined Analysis
  60. GRB 080207: Enhanced Swift-XRT position
  61. GRB 080207: Swift detection of a burst
  62. Konus-Wind observation of GRB 080204
  63. GRB 080205 optical upper limit
  64. GRB 080205: MASTER optical observation
  65. GRB 080205: optical observation
  66. VLA radio upper limit on GRB 080205
  67. INT+WFC R-band observations of GRB 080205
  68. GRB 080205, Swift-BAT refined analysis
  69. IPN localization of very hard GRB 080204
  70. GRB 080205: Swift XRT refined analysis
  71. GRB 080205: OA evolution from KAIT observations
  72. GRB 080205: Swift/UVOT observations
  73. GRB 080205: Enhanced Swift-XRT position
  74. GRB 080205: KAIT OA detection
  75. GRB 080205: Swift detection of a burst
  76. Swift-BAT Trigger #302454, correction of GCN notice, update on AX J1749.1-2639
  77. GRB 080130: Swift-BAT refined analysis
  78. GRB 080130: further Swift XRT observations confirm fading source
  79. GRB 080129: Swift/UVOT Refined Upper Limits
  80. Swift/UVOT observations of GRB080130
  81. GRB 080130: REM NIR observations
  82. GRB 080130(?): Swift XRT observation
  83. GRB 080130?: Detection of a possible burst by BATSS
  84. GRB 080129: Optical observations from OSN
  85. GRB 080129: Swift-XRT refined analysis
  86. X-ray transient in NGC 2770: RTT150 optical observations
  87. GRB 080129: KAIT optical limits
  88. GRB 080123: Early afterglow detection with BATSS (BAT Slew Survey)
  89. GRB 080129: optical limit by Pi of the Sky
  90. GRB 080129, Swift-BAT refined analysis
  91. GRB 080129: TAROT La Silla observatory optical observations
  92. GRB 080129: Gemini-South photometry
  93. GRB 080129: GROND detection in all bands, and fading
  94. GRB 080129: GROND detection of the optical/NIR afterglow, and fading
  95. GRB 080129: Enhanced Swift-XRT position
  96. GRB 080129: Gemini-South Imaging Observations
  97. GRB 080129: Swift XRT position
  98. GRB 080129 (?): UVOT Upper Limits
  99. GRB 080129 (?): Swift detection of a possible burst
  100. A new website of high-level data products for Swift GRBs

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