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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. IBAS Alert n. 5257 : not a GRB
  2. GRB 080413B: Ep,i-Eiso correlation
  3. GRB080413B
  4. Swift-BAT spectral lag analysis of GRB 080413B
  5. GRB 080413a, SMARTS optical/IR afterglow observations
  6. GRB 080413B: Swift XRT refined analysis
  7. GRB080413A: Swift/UVOT observations
  8. GRB 080413B, Swift-BAT refined analysis
  9. GRB 080413A: Swift-XRT refined analysis
  10. GRB 080413A, Swift-BAT refined analysis
  11. GRB 080413A Bootes observation
  12. GRB 080413A: VLT/UVES redshift
  13. GRB 080413B: VLT redshift
  14. GRB080413B: REM NIR & Optical Observation
  15. GRB 080413B: GROND detection of afterglow in all bands
  16. GRB 080413B: Swift detection of a possibly short burst with optical counterpart
  17. GRB 080413A: REM detection of the NIR Afterglow
  18. GRB 080413: Enhanced Swift-XRT position
  19. GRB 080413: TAROT Calern observatory optical observations
  20. GRB 080413: Swift detection of a burst with an optical afterglow
  21. GRB 080413: ROTSE-III Detection of Optical Counterpart
  22. GRB 080411: Swift/UVOT refined analysis
  23. GRB 080411, Swift-BAT refined analysis
  24. GRB 080411: Swift-XRT Refined Analysis
  25. Konus-Wind observation of GRB 080411
  26. GRB 080411: Enhanced Swift-XRT position
  27. GRB 080411: VLT redshift
  28. GRB 080411: GROND detection of optical afterglow candidate
  29. GRB080330: MAGIC telescope GeV observation
  30. GRB 080411: Swift detection of a bright burst
  31. GRB 080330: Swift-XRT refined position retraction
  32. GRB 080409: Swift-BAT refined analysis
  33. GRB 080408: GROND detection of optical/NIR afterglow candidate
  34. GRB 080330 optical observations
  35. Swift/UVOT observations of GRB080409
  36. GRB 080409: Swift XRT refined analysis
  37. UVOT/Swift Observations of GRB080408
  38. GRB 080408: Swift-XRT position of a possible afterglow
  39. GRB 080409: Enhanced Swift-XRT position
  40. GRB 080409: REM optical/NIR observations
  41. GRB 080409: Swift detection of a burst
  42. GRB 080408: Analysis of AGILE Gamma-ray data
  43. GRB 080408: GRB Localization by SuperAGILE
  44. GRB 080319A: Early RAPTOR optical limits
  45. GRB 080319B: HST observations
  46. GRB 080330: RAPTOR detection of prompt optical flash
  47. GRB 080319B: Potential Jet Break Observed by Swift-XRT and UVOT
  48. GRB 080405: Swift-BAT refined analysis
  49. GRB 080405: Swift-XRT position
  50. GRB 080405: Mars Oddysey and Swift-BAT detection, possible host galaxy
  51. GRB 080325: optical upper limit
  52. GRB 080328: GAO 150cm telescope Optical Observation
  53. GRB080330: Improved Swift XRT Position
  54. GRB 080330: Prompt PROMPT Observations
  55. GRB080330: optical observations
  56. GRB 080319B: TORTORA light curve (Correction)
  57. GRB080328, RIMOTS optical upper limit
  58. GRB080330: optical observations
  59. GRB080330: Swift XRT refined analysis
  60. GRB 080330: REM optical observations
  61. GRB 080330, SMARTS optical/IR afterglow observations
  62. GRB 080330 Swift-UVOT refined analysis
  63. GRB 080328: Suzaku WAM observation of the prompt emission
  64. GRB080330: TNT optical observations
  65. GRB 080330, Swift-BAT refined analysis
  66. Konus-Wind observation of GRB 080328
  67. GRB 080330: Redshift Confirmation from Hobby-Eberly Telescope Spectroscopy
  68. GRB080330: LOAO R-band Detection
  69. GRB 080330: GROND Observations
  70. GRB 080330: NOT redshift
  71. GRB 080330: TAROT Calern observatory optical observations
  72. GRB 080330A: PAIRITEL Infrared Detections
  73. GRB 080330: error in reported XRT position
  74. GRB080330 - SDSS Pre-Burst Observations
  75. GRB 080330: Liverpool Telescope Optical observations
  76. GRB 080330A: ROTSE-III Detection of Optical Counterpart
  77. GRB 080330: Swift detection of a burst with an optical counterpart
  78. GRB 080330: TAROT Calern observatory optical detection
  79. GRB 080319B: Continued Gemini-South followup and possible host galaxy
  80. GRB 080328: BTA optical imaging and spectroscopy
  81. GRB 080328, Swift-BAT refined analysis
  82. GRB 080328: Swift XRT refined analysis
  83. GRB 080325, Swift-BAT refined analysis
  84. Swift/UVOT observations of GRB080328
  85. GRB080325 - I and z-band Imaging
  86. GRB080319B, BVRcIc field calibration
  87. GRB 080328: Enhanced Swift-XRT position
  88. GRB080328: Faulkes Telescope North observations
  89. GRB 080328: Swift detection of a burst with an optical counterpart
  90. GRB 080325: Subaru detection of NIR afterglow candidate
  91. GRB080310, late-time photometry with LBT
  92. GRB 080325: MITSuME Akeno optical upper limits
  93. GRB080325: XRT Refined Analysis
  94. GRB 080325: GROND Observations
  95. GRB080319B: optical observations
  96. GRB 080325: Swift/UVOT Upper Limits
  97. GRB 080319C: Gemini-North spectroscopic redshift
  98. GRB 080325: Early observations from OSN
  99. GRB 080325: NIR afterglow candidate
  100. GRB 080319D: GROND Detection of the Optical Counterpart

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