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

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