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

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