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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 080330: Liverpool Telescope Optical observations
  2. GRB 080330A: ROTSE-III Detection of Optical Counterpart
  3. GRB 080330: Swift detection of a burst with an optical counterpart
  4. GRB 080330: TAROT Calern observatory optical detection
  5. GRB 080319B: Continued Gemini-South followup and possible host galaxy
  6. GRB 080328: BTA optical imaging and spectroscopy
  7. GRB 080328, Swift-BAT refined analysis
  8. GRB 080328: Swift XRT refined analysis
  9. GRB 080325, Swift-BAT refined analysis
  10. Swift/UVOT observations of GRB080328
  11. GRB080325 - I and z-band Imaging
  12. GRB080319B, BVRcIc field calibration
  13. GRB 080328: Enhanced Swift-XRT position
  14. GRB080328: Faulkes Telescope North observations
  15. GRB 080328: Swift detection of a burst with an optical counterpart
  16. GRB 080325: Subaru detection of NIR afterglow candidate
  17. GRB080310, late-time photometry with LBT
  18. GRB 080325: MITSuME Akeno optical upper limits
  19. GRB080325: XRT Refined Analysis
  20. GRB 080325: GROND Observations
  21. GRB080319B: optical observations
  22. GRB 080325: Swift/UVOT Upper Limits
  23. GRB 080319C: Gemini-North spectroscopic redshift
  24. GRB 080325: Early observations from OSN
  25. GRB 080325: NIR afterglow candidate
  26. GRB 080319D: GROND Detection of the Optical Counterpart
  27. GRB 080325: Enhanced Swift-XRT position
  28. GRB 080325: Swift detection of a burst
  29. GRB 080319B : Apparent spectral evolution in very early Swift/XRT WT mode data: intrinsic or pile-up effect?
  30. IBAS Alert n. 5245: NOT a GRB
  31. GRB 080319B: Spitzer Mid-infrared Observations
  32. GRB 080319C: Suzaku WAM observation of the prompt emission
  33. GRB 080319B: Second & Third Epoch WSRT Radio Observations
  34. Radio Detection of GRB 080319B
  35. GRB 080320, Swift-BAT refined analysis
  36. GRB 080319B: Optical observation (Brno, CZ)
  37. GRB 080319D: GROND Observations
  38. GRB 080319B: TORTORA light curve
  39. GRB 080319B: optical upper limit
  40. GRB 080319D: optical upper limit
  41. GRB080319B: Time-Independent XRT Spectrum
  42. GRB 080319D, Swift-BAT refined analysis
  43. GRB 080319C: UVOT Observations
  44. GRB 080319B: UVOT Observations
  45. GRB 080319A: UVOT Observations
  46. GRB 080320: Swift XRT refined analysis
  47. GRB 080319B - CARMA mm Observations
  48. GRB 080320: Early Super-LOTIS Observations
  49. GRB 080320: J detection with FLAMINGOS
  50. GRB 080319D: Swift XRT refined analysis
  51. GRB 080320: optical limit
  52. GRB 080320: Gemini-N optical afterglow
  53. Konus-Wind observation of GRB 080319C
  54. GRB 080319B: Gemini-South photometry
  55. GRB 080319B: Allen Telescope Array Observations
  56. GRB 080319B optical observations
  57. GRB 080319C, Swift-BAT refined analysis
  58. Konus-Wind observation of GRB 080319B
  59. GRB 080319B: WSRT Radio Observations
  60. GRB 080320: SDSS source and Gemini-N observations
  61. GRB 080320: Enhanced Swift-XRT position
  62. GRB 080320: optical limit from IAC80
  63. GRB 080319C: Early RAPTOR Observations
  64. GRB 080319B: second epoch imaging from Canarias (correction to GCN7469)
  65. GRB 080319C: KAIT OA observations
  66. GRB 080320 - SDSS Pre-Burst Observations
  67. GRB 080320: Swift detection of a burst
  68. GRB 080320: ROTSE-III Optical Limits
  69. GRB 080319B : Lulin observation of temporal break at 0.2 days
  70. GRB 080319B: ROTSE-III Observations of Optical Counterpart
  71. GRB 080319B: optical observations
  72. GRB 080319C - SDSS Pre-Burst Observations
  73. GRB 080319A SDSS Pre-Burst Observations
  74. Swift-BAT trigger 306829 is IGR J16479-4514
  75. GRB080319B - SDSS Pre-Burst Observations
  76. GRB 080319B: RAPTOR observations of a naked eye burst
  77. GRB 080319A: Swift-XRT Team Refined Analysis
  78. GRB 080319B, Swift-BAT refined analysis
  79. GRB080319B: Prompt PROMPT Detections
  80. GRB 080319C: Swift-XRT Team Refined Analysis
  81. GRB 080319B: Swift-XRT Team Refined Analysis
  82. GRB 080319D: Swift/UVOT Refined Analysis of the Fading Optical Afterglow Candidate
  83. GRB 080319C: AGILE-MCAL observation of the prompt emission
  84. GRB 080319B: Hobby-Eberly Telescope Spectroscopy
  85. GRB 080319D: MASTER-VWF-Kislovodsk optical observation
  86. GRB 080319C: MASTER-VWF-Kislovodsk optical observation
  87. GRB 080319D: Swift detection of a burst with a possible optical afterglow
  88. GRB 080319B: TORTORA synchronous observation
  89. VLT/UVES redshift of GRB 080319B from FeII fine-structure lines
  90. GRB 080319A/B/C: INTEGRAL SPI-ACS light curves available
  91. GRB 080319B: Enhanced Swift-XRT position
  92. GRB 080319A: Enhanced Swift-XRT position
  93. GRB 080319A, Swift-BAT refined analysis
  94. GRB 080319B: REM early data
  95. GRB 080319b light curve by Pi-of-the-Sky
  96. VLT/UVES redshift of GRB 080319B
  97. GRB 080319C: Early Super-LOTIS Observations
  98. GRB 080319C: Swift detection of a burst with an optical afterglow
  99. GRB 080319C: KAIT OA candidate
  100. GRB 080319A: REM observations

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