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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. GRB080307, optical upper limit
  2. GRB080307 BOAO optical afterglow observation - detection of a possible OT
  3. GRB080229, optical upper limit
  4. GRB 080307: Swift-XRT Team refined analysis
  5. GRB 080307: Swift/UVOT Upper Limits
  6. GRB 080307: Early RAPTOR Limits
  7. GRB 080307, Swift-BAT refined analysis
  8. GRB080307 - SDSS Pre-Burst Observations
  9. GRB 080307: TNT optical observation
  10. GRB080307: Optical upper limits
  11. GRB 080307: Gemini-N i-band observations - candidate afterglow
  12. GRB 080307: BOAO imaging - retraction and new limit
  13. GRB 080307: retraction of UVOT candidate
  14. GRB 080307: Enhanced Swift-XRT position
  15. GRB 080307, Preliminary Swift-BAT refined analysis
  16. GRB 080307 : BOAO optical afterglow observation
  17. GRB 080307: Optical observation with DMC/KANATA
  18. GRB 080307: Swift detection of a burst
  19. VLA possible radio detection of GRB 080229
  20. GRB 080303: Swift/UVOT follow-up of afterglow detection
  21. GRB 080303, Swift-BAT refined analysis
  22. GRB 080303: Rapid PROMPT Detections
  23. GRB080303: Swift XRT refined analysis
  24. GRB 080303: Enhanced Swift-XRT position
  25. Swift UVOT observations of GRB080229B
  26. GRB080229B: Swift XRT afterglow observation
  27. GRB 080303A: Faulkes Telescope South optical afterglow observations
  28. GRB 080303
  29. GRB 080303: Swift detection of a burst with optical afterglow
  30. GRB 080303: REM NIR afterglow candidate
  31. GRB 080303A: ROTSE-III Optical Limits
  32. GRB 080229: I-band observations from OSN
  33. GRB 080229: VLT NIR observations
  34. GRB080229: Swift XRT refined analysis
  35. GRB 080229: TNG NIR observations
  36. GRB 080229: Deep Gemini/GMOS optical observations
  37. GRB 080229: Enhanced Swift-XRT position
  38. GRB 080229: REM NIR observations
  39. GRB080229: Possible optical afterglow
  40. GRB 080229B: Gamma Ray Burst Localization by SuperAGILE
  41. UVOT analysis for GRB080229
  42. GRB 080229, Swift-BAT refined analysis
  43. GRB 080229: Faulkes Telescope South optical limit
  44. GRB 080229A: ROTSE-III Optical Limits
  45. GRB 080229: Swift detection of a bright burst
  46. Early optical shallow decay in GRB 071112C
  47. GRB080207: optical observations
  48. GRB080205: optical observations
  49. GRB080211: optical observations
  50. XRF 080109/SN2008D : GMRT upper limit at 1.28 GHz
  51. GRB 071010B : Early optical brightening detected by TAOS
  52. Swift-XRT improved positions, and new redshift limits.
  53. ESO optical and NIR observations of GRB 080218B
  54. GRB 080204: Suzaku WAM observation of the prompt emission
  55. GRB 080218B, Swift-BAT refined analysis
  56. GRB 080218B: Swift-XRT refined analysis
  57. Swift/UVOT observations of GRB080218B
  58. GRB 080218B: REM NIR early upper limits
  59. GRB 080212: Mount Abu NIR observations
  60. GRB 080218B: Enhanced Swift-XRT position
  61. GRB 080218B: GROND upper limits
  62. GRB 080218b, SMARTS optical/IR limits
  63. GRB 080218A, Swift-BAT refined analysis
  64. GRB080218B: Watcher prompt limit
  65. GRB 080211: Suzaku WAM observation of the prompt emission
  66. GRB 080218B: Swift detection of a burst
  67. GRB 080218: Swift detection of a burst
  68. Swift-XRT and UVOT observations of the IPN burst GRB 080211
  69. GRB 080212: VLT optical rapid decay
  70. GRB 080212: REM refined analysis
  71. Konus-Wind observation of GRB 080211
  72. VLA radio upper limit on GRB 080212
  73. Swift/UVOT refined analysis of GRB080212
  74. GRB 080212, Swift-BAT refined analysis
  75. GRB080212: Optical afterglow candidate observed by MITSuME Telescope
  76. GRB 080212: Gemini-South optical observations
  77. GRB 080212: GROND detects afterglow
  78. GRB 080212: REM NIR afterglow?
  79. GRB 080212: optical observations
  80. GRB 080212: Enhanced Swift-XRT position
  81. GRB 080212: Swift-XRT Team refined analysis
  82. GRB 080210: Keck photometry
  83. VLA non-detection of GRB 080210
  84. GRB 080212: Swift detection of a burst
  85. IPN localization of GRB 080211
  86. GRB 080212: DSS/2MASS Galaxy at XRT position
  87. GRB 080207: VLT NIR early upper limits
  88. GRB 080210: Swift/UVOT Refined Analysis
  89. GRB 080207: optical observations.
  90. GRB 080210: Hobby-Eberly Telescope Absorption Spectroscopy
  91. GRB 080210, Swift-BAT refined analysis
  92. GRB 080210: Super-LOTIS observations
  93. GRB 080210: Swift-XRT Refined Analysis
  94. GRB 080210: VLT redshift
  95. GRB 080210: Enhanced Swift-XRT position
  96. GRB 080210: Rapid PROMPT Detections
  97. GRB 080210: GOND detection in all bands and redshift upper limit
  98. GRB080210 - SDSS Pre-Burst Observations
  99. GRB 080210: Swift detection of a burst with optical afterglow
  100. GRB 080210: TAROT La Silla observatory optical detection

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