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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: GAO 150cm telescope Optical Observation
  2. GRB 080229A: GAO 150cm telescope Optical Observation
  3. GRB 080310: PAIRITEL detection and PAIRITEL+KAIT+UVOT SED
  4. GRB 080307: NIR upper limit
  5. GRB 080229: NIR upper limit
  6. GRB 080310: early RAPTOR multicolor observations
  7. GRB 080310, Swift-BAT refined analysis
  8. GRB080210: optical observations
  9. GRB080307: optical upper limit
  10. GRB 080310: Swift-XRT refined analysis
  11. GRB 080310: Swift/UVOT Refined Analysis
  12. GRB 080310: Redshift from Keck/DEIMOS Spectra
  13. GRB 080310 - SDSS Pre-Burst Observations
  14. GRB080310 : Lulin optical observation
  15. GRB 080310: Enhanced Swift-XRT position
  16. GRB 080310: RRM optical photometry with the VLT
  17. GRB080310, detection of break in optical
  18. GRB 080310: VLT/UVES spectroscopy
  19. GRB080310, optical observations with LBT
  20. GRB 080310: Magellan redshift revision
  21. GRB 080310: Lick/Kast Spectroscopy
  22. GRB080310: Super-LOTIS suggestion of brightening
  23. GRB 080310, SMARTS optical/IR afterglow observations
  24. GRB 080310: REM observations
  25. GRB 080310: Magellan redshift
  26. GRB 080310 afterglow candidate (correction to UT time)
  27. GRB 080310: Swift detection of a burst with optical afterglow
  28. GRB 080310 afterglow candidate
  29. GRB080229, optical upper limit (Correction)
  30. GRB080307, optical upper limit
  31. GRB080307 BOAO optical afterglow observation - detection of a possible OT
  32. GRB080229, optical upper limit
  33. GRB 080307: Swift-XRT Team refined analysis
  34. GRB 080307: Swift/UVOT Upper Limits
  35. GRB 080307: Early RAPTOR Limits
  36. GRB 080307, Swift-BAT refined analysis
  37. GRB080307 - SDSS Pre-Burst Observations
  38. GRB 080307: TNT optical observation
  39. GRB080307: Optical upper limits
  40. GRB 080307: Gemini-N i-band observations - candidate afterglow
  41. GRB 080307: BOAO imaging - retraction and new limit
  42. GRB 080307: retraction of UVOT candidate
  43. GRB 080307: Enhanced Swift-XRT position
  44. GRB 080307, Preliminary Swift-BAT refined analysis
  45. GRB 080307 : BOAO optical afterglow observation
  46. GRB 080307: Optical observation with DMC/KANATA
  47. GRB 080307: Swift detection of a burst
  48. VLA possible radio detection of GRB 080229
  49. GRB 080303: Swift/UVOT follow-up of afterglow detection
  50. GRB 080303, Swift-BAT refined analysis
  51. GRB 080303: Rapid PROMPT Detections
  52. GRB080303: Swift XRT refined analysis
  53. GRB 080303: Enhanced Swift-XRT position
  54. Swift UVOT observations of GRB080229B
  55. GRB080229B: Swift XRT afterglow observation
  56. GRB 080303A: Faulkes Telescope South optical afterglow observations
  57. GRB 080303
  58. GRB 080303: Swift detection of a burst with optical afterglow
  59. GRB 080303: REM NIR afterglow candidate
  60. GRB 080303A: ROTSE-III Optical Limits
  61. GRB 080229: I-band observations from OSN
  62. GRB 080229: VLT NIR observations
  63. GRB080229: Swift XRT refined analysis
  64. GRB 080229: TNG NIR observations
  65. GRB 080229: Deep Gemini/GMOS optical observations
  66. GRB 080229: Enhanced Swift-XRT position
  67. GRB 080229: REM NIR observations
  68. GRB080229: Possible optical afterglow
  69. GRB 080229B: Gamma Ray Burst Localization by SuperAGILE
  70. UVOT analysis for GRB080229
  71. GRB 080229, Swift-BAT refined analysis
  72. GRB 080229: Faulkes Telescope South optical limit
  73. GRB 080229A: ROTSE-III Optical Limits
  74. GRB 080229: Swift detection of a bright burst
  75. Early optical shallow decay in GRB 071112C
  76. GRB080207: optical observations
  77. GRB080205: optical observations
  78. GRB080211: optical observations
  79. XRF 080109/SN2008D : GMRT upper limit at 1.28 GHz
  80. GRB 071010B : Early optical brightening detected by TAOS
  81. Swift-XRT improved positions, and new redshift limits.
  82. ESO optical and NIR observations of GRB 080218B
  83. GRB 080204: Suzaku WAM observation of the prompt emission
  84. GRB 080218B, Swift-BAT refined analysis
  85. GRB 080218B: Swift-XRT refined analysis
  86. Swift/UVOT observations of GRB080218B
  87. GRB 080218B: REM NIR early upper limits
  88. GRB 080212: Mount Abu NIR observations
  89. GRB 080218B: Enhanced Swift-XRT position
  90. GRB 080218B: GROND upper limits
  91. GRB 080218b, SMARTS optical/IR limits
  92. GRB 080218A, Swift-BAT refined analysis
  93. GRB080218B: Watcher prompt limit
  94. GRB 080211: Suzaku WAM observation of the prompt emission
  95. GRB 080218B: Swift detection of a burst
  96. GRB 080218: Swift detection of a burst
  97. Swift-XRT and UVOT observations of the IPN burst GRB 080211
  98. GRB 080212: VLT optical rapid decay
  99. GRB 080212: REM refined analysis
  100. Konus-Wind observation of GRB 080211

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