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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 080310: RRM optical photometry with the VLT
  2. GRB080310, detection of break in optical
  3. GRB 080310: VLT/UVES spectroscopy
  4. GRB080310, optical observations with LBT
  5. GRB 080310: Magellan redshift revision
  6. GRB 080310: Lick/Kast Spectroscopy
  7. GRB080310: Super-LOTIS suggestion of brightening
  8. GRB 080310, SMARTS optical/IR afterglow observations
  9. GRB 080310: REM observations
  10. GRB 080310: Magellan redshift
  11. GRB 080310 afterglow candidate (correction to UT time)
  12. GRB 080310: Swift detection of a burst with optical afterglow
  13. GRB 080310 afterglow candidate
  14. GRB080229, optical upper limit (Correction)
  15. GRB080307, optical upper limit
  16. GRB080307 BOAO optical afterglow observation - detection of a possible OT
  17. GRB080229, optical upper limit
  18. GRB 080307: Swift-XRT Team refined analysis
  19. GRB 080307: Swift/UVOT Upper Limits
  20. GRB 080307: Early RAPTOR Limits
  21. GRB 080307, Swift-BAT refined analysis
  22. GRB080307 - SDSS Pre-Burst Observations
  23. GRB 080307: TNT optical observation
  24. GRB080307: Optical upper limits
  25. GRB 080307: Gemini-N i-band observations - candidate afterglow
  26. GRB 080307: BOAO imaging - retraction and new limit
  27. GRB 080307: retraction of UVOT candidate
  28. GRB 080307: Enhanced Swift-XRT position
  29. GRB 080307, Preliminary Swift-BAT refined analysis
  30. GRB 080307 : BOAO optical afterglow observation
  31. GRB 080307: Optical observation with DMC/KANATA
  32. GRB 080307: Swift detection of a burst
  33. VLA possible radio detection of GRB 080229
  34. GRB 080303: Swift/UVOT follow-up of afterglow detection
  35. GRB 080303, Swift-BAT refined analysis
  36. GRB 080303: Rapid PROMPT Detections
  37. GRB080303: Swift XRT refined analysis
  38. GRB 080303: Enhanced Swift-XRT position
  39. Swift UVOT observations of GRB080229B
  40. GRB080229B: Swift XRT afterglow observation
  41. GRB 080303A: Faulkes Telescope South optical afterglow observations
  42. GRB 080303
  43. GRB 080303: Swift detection of a burst with optical afterglow
  44. GRB 080303: REM NIR afterglow candidate
  45. GRB 080303A: ROTSE-III Optical Limits
  46. GRB 080229: I-band observations from OSN
  47. GRB 080229: VLT NIR observations
  48. GRB080229: Swift XRT refined analysis
  49. GRB 080229: TNG NIR observations
  50. GRB 080229: Deep Gemini/GMOS optical observations
  51. GRB 080229: Enhanced Swift-XRT position
  52. GRB 080229: REM NIR observations
  53. GRB080229: Possible optical afterglow
  54. GRB 080229B: Gamma Ray Burst Localization by SuperAGILE
  55. UVOT analysis for GRB080229
  56. GRB 080229, Swift-BAT refined analysis
  57. GRB 080229: Faulkes Telescope South optical limit
  58. GRB 080229A: ROTSE-III Optical Limits
  59. GRB 080229: Swift detection of a bright burst
  60. Early optical shallow decay in GRB 071112C
  61. GRB080207: optical observations
  62. GRB080205: optical observations
  63. GRB080211: optical observations
  64. XRF 080109/SN2008D : GMRT upper limit at 1.28 GHz
  65. GRB 071010B : Early optical brightening detected by TAOS
  66. Swift-XRT improved positions, and new redshift limits.
  67. ESO optical and NIR observations of GRB 080218B
  68. GRB 080204: Suzaku WAM observation of the prompt emission
  69. GRB 080218B, Swift-BAT refined analysis
  70. GRB 080218B: Swift-XRT refined analysis
  71. Swift/UVOT observations of GRB080218B
  72. GRB 080218B: REM NIR early upper limits
  73. GRB 080212: Mount Abu NIR observations
  74. GRB 080218B: Enhanced Swift-XRT position
  75. GRB 080218B: GROND upper limits
  76. GRB 080218b, SMARTS optical/IR limits
  77. GRB 080218A, Swift-BAT refined analysis
  78. GRB080218B: Watcher prompt limit
  79. GRB 080211: Suzaku WAM observation of the prompt emission
  80. GRB 080218B: Swift detection of a burst
  81. GRB 080218: Swift detection of a burst
  82. Swift-XRT and UVOT observations of the IPN burst GRB 080211
  83. GRB 080212: VLT optical rapid decay
  84. GRB 080212: REM refined analysis
  85. Konus-Wind observation of GRB 080211
  86. VLA radio upper limit on GRB 080212
  87. Swift/UVOT refined analysis of GRB080212
  88. GRB 080212, Swift-BAT refined analysis
  89. GRB080212: Optical afterglow candidate observed by MITSuME Telescope
  90. GRB 080212: Gemini-South optical observations
  91. GRB 080212: GROND detects afterglow
  92. GRB 080212: REM NIR afterglow?
  93. GRB 080212: optical observations
  94. GRB 080212: Enhanced Swift-XRT position
  95. GRB 080212: Swift-XRT Team refined analysis
  96. GRB 080210: Keck photometry
  97. VLA non-detection of GRB 080210
  98. GRB 080212: Swift detection of a burst
  99. IPN localization of GRB 080211
  100. GRB 080212: DSS/2MASS Galaxy at XRT position

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