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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 080413A: REM detection of the NIR Afterglow
  2. GRB 080413: Enhanced Swift-XRT position
  3. GRB 080413: TAROT Calern observatory optical observations
  4. GRB 080413: Swift detection of a burst with an optical afterglow
  5. GRB 080413: ROTSE-III Detection of Optical Counterpart
  6. GRB 080411: Swift/UVOT refined analysis
  7. GRB 080411, Swift-BAT refined analysis
  8. GRB 080411: Swift-XRT Refined Analysis
  9. Konus-Wind observation of GRB 080411
  10. GRB 080411: Enhanced Swift-XRT position
  11. GRB 080411: VLT redshift
  12. GRB 080411: GROND detection of optical afterglow candidate
  13. GRB080330: MAGIC telescope GeV observation
  14. GRB 080411: Swift detection of a bright burst
  15. GRB 080330: Swift-XRT refined position retraction
  16. GRB 080409: Swift-BAT refined analysis
  17. GRB 080408: GROND detection of optical/NIR afterglow candidate
  18. GRB 080330 optical observations
  19. Swift/UVOT observations of GRB080409
  20. GRB 080409: Swift XRT refined analysis
  21. UVOT/Swift Observations of GRB080408
  22. GRB 080408: Swift-XRT position of a possible afterglow
  23. GRB 080409: Enhanced Swift-XRT position
  24. GRB 080409: REM optical/NIR observations
  25. GRB 080409: Swift detection of a burst
  26. GRB 080408: Analysis of AGILE Gamma-ray data
  27. GRB 080408: GRB Localization by SuperAGILE
  28. GRB 080319A: Early RAPTOR optical limits
  29. GRB 080319B: HST observations
  30. GRB 080330: RAPTOR detection of prompt optical flash
  31. GRB 080319B: Potential Jet Break Observed by Swift-XRT and UVOT
  32. GRB 080405: Swift-BAT refined analysis
  33. GRB 080405: Swift-XRT position
  34. GRB 080405: Mars Oddysey and Swift-BAT detection, possible host galaxy
  35. GRB 080325: optical upper limit
  36. GRB 080328: GAO 150cm telescope Optical Observation
  37. GRB080330: Improved Swift XRT Position
  38. GRB 080330: Prompt PROMPT Observations
  39. GRB080330: optical observations
  40. GRB 080319B: TORTORA light curve (Correction)
  41. GRB080328, RIMOTS optical upper limit
  42. GRB080330: optical observations
  43. GRB080330: Swift XRT refined analysis
  44. GRB 080330: REM optical observations
  45. GRB 080330, SMARTS optical/IR afterglow observations
  46. GRB 080330 Swift-UVOT refined analysis
  47. GRB 080328: Suzaku WAM observation of the prompt emission
  48. GRB080330: TNT optical observations
  49. GRB 080330, Swift-BAT refined analysis
  50. Konus-Wind observation of GRB 080328
  51. GRB 080330: Redshift Confirmation from Hobby-Eberly Telescope Spectroscopy
  52. GRB080330: LOAO R-band Detection
  53. GRB 080330: GROND Observations
  54. GRB 080330: NOT redshift
  55. GRB 080330: TAROT Calern observatory optical observations
  56. GRB 080330A: PAIRITEL Infrared Detections
  57. GRB 080330: error in reported XRT position
  58. GRB080330 - SDSS Pre-Burst Observations
  59. GRB 080330: Liverpool Telescope Optical observations
  60. GRB 080330A: ROTSE-III Detection of Optical Counterpart
  61. GRB 080330: Swift detection of a burst with an optical counterpart
  62. GRB 080330: TAROT Calern observatory optical detection
  63. GRB 080319B: Continued Gemini-South followup and possible host galaxy
  64. GRB 080328: BTA optical imaging and spectroscopy
  65. GRB 080328, Swift-BAT refined analysis
  66. GRB 080328: Swift XRT refined analysis
  67. GRB 080325, Swift-BAT refined analysis
  68. Swift/UVOT observations of GRB080328
  69. GRB080325 - I and z-band Imaging
  70. GRB080319B, BVRcIc field calibration
  71. GRB 080328: Enhanced Swift-XRT position
  72. GRB080328: Faulkes Telescope North observations
  73. GRB 080328: Swift detection of a burst with an optical counterpart
  74. GRB 080325: Subaru detection of NIR afterglow candidate
  75. GRB080310, late-time photometry with LBT
  76. GRB 080325: MITSuME Akeno optical upper limits
  77. GRB080325: XRT Refined Analysis
  78. GRB 080325: GROND Observations
  79. GRB080319B: optical observations
  80. GRB 080325: Swift/UVOT Upper Limits
  81. GRB 080319C: Gemini-North spectroscopic redshift
  82. GRB 080325: Early observations from OSN
  83. GRB 080325: NIR afterglow candidate
  84. GRB 080319D: GROND Detection of the Optical Counterpart
  85. GRB 080325: Enhanced Swift-XRT position
  86. GRB 080325: Swift detection of a burst
  87. GRB 080319B : Apparent spectral evolution in very early Swift/XRT WT mode data: intrinsic or pile-up effect?
  88. IBAS Alert n. 5245: NOT a GRB
  89. GRB 080319B: Spitzer Mid-infrared Observations
  90. GRB 080319C: Suzaku WAM observation of the prompt emission
  91. GRB 080319B: Second & Third Epoch WSRT Radio Observations
  92. Radio Detection of GRB 080319B
  93. GRB 080320, Swift-BAT refined analysis
  94. GRB 080319B: Optical observation (Brno, CZ)
  95. GRB 080319D: GROND Observations
  96. GRB 080319B: TORTORA light curve
  97. GRB 080319B: optical upper limit
  98. GRB 080319D: optical upper limit
  99. GRB080319B: Time-Independent XRT Spectrum
  100. GRB 080319D, Swift-BAT refined analysis

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