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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"

17851 results found.

  1. GRB 080506: NAYUTA Optical Observation
  2. GRB 080507: Keck photometry
  3. GRB 080503: Chandra Observation of X-ray Rebrightening or Flattening
  4. GRB 080507: Optical Afterglow
  5. GRB 080506:Optical observations from HCT
  6. GRB 080506: VLA radio upper limit
  7. GRB 080506: Swift XRT refined analysis
  8. GRB080506: Swift/UVOT observations
  9. GRB080503, RIMOTS optical upper limit
  10. GRB 080506: Observations from NOT
  11. GRB 080506: Enhanced Swift-XRT position
  12. GRB 080506: Swift detection of a burst with optical afterglow
  13. GRB 080503: VLA radio upper limit
  14. GRB 080503: Observations from NOT
  15. GRB 080430: TLS imaging one day after the GRB
  16. GRB 080503, Swift-BAT lag and time-resolved spectral analysis
  17. GRB 080503: MITSuME Ishigakijima optical upper limits
  18. GRB 080430
  19. GRB 080430
  20. GRB 080503: Enhanced Swift-XRT position
  21. GRB 080503: MITSuME Akeno optical upper limits
  22. GRB 080503: New candidate afterglow/host in Gemini imaging
  23. GRB 080503: Swift detection of a short burst
  24. GRB080430: Swift/UVOT observations
  25. VLA radio upper limit on GRB 080430
  26. GRB 080430: Enhanced Swift-XRT position
  27. GRB 080430 - SDSS Pre-Burst Observations
  28. GRB 080430: Swift detection of a burst with optical afterglow
  29. GRB 080430: TAROT Calern observatory optical observations
  30. GRB080426: Swift/UVOT upper limits
  31. GRB 080426: Enhanced Swift-XRT position
  32. GRB 080426, Swift-BAT refined analysis
  33. GRB 080426: Swift detection of a possibly short burst
  34. GRB 080320 : Faulkes Telescope North Observations
  35. GRB 080319A : Liverpool and Faulkes Telescopes Observations
  36. GRB 080420A: ROTSE-III Optical Limits on a possible short burst
  37. GRB080310, BVRcIc field calibration
  38. Swift XRT and UVOT observations of GRB080414
  39. GRB 080413B: Faulkes Telescope South optical afterglow observations
  40. GRB 080413A: Liverpool Telescope and Faulkes Telescope South optical observations
  41. GRB 080414: RTT150 optical observations
  42. VLA radio observations of GRB 080413B
  43. VLA radio observations of GRB 080413A
  44. GRB080413B
  45. GRB 080413a, SMARTS optical/IR afterglow observations
  46. GRB080413A: Swift/UVOT observations
  47. GRB 080413A: Swift-XRT refined analysis
  48. GRB080413B: REM NIR & Optical Observation
  49. GRB 080413B: GROND detection of afterglow in all bands
  50. GRB 080413B: Swift detection of a possibly short burst with optical counterpart
  51. GRB 080413A: REM detection of the NIR Afterglow
  52. GRB 080413: Enhanced Swift-XRT position
  53. GRB 080413: TAROT Calern observatory optical observations
  54. GRB 080413: Swift detection of a burst with an optical afterglow
  55. GRB 080411: Swift/UVOT refined analysis
  56. GRB 080411: Swift-XRT Refined Analysis
  57. GRB 080411: Enhanced Swift-XRT position
  58. GRB 080411: GROND detection of optical afterglow candidate
  59. GRB 080411: Swift detection of a bright burst
  60. GRB 080408: GROND detection of optical/NIR afterglow candidate
  61. GRB 080330 optical observations
  62. Swift/UVOT observations of GRB080409
  63. GRB 080409: Enhanced Swift-XRT position
  64. GRB 080409: REM optical/NIR observations
  65. GRB 080409: Swift detection of a burst
  66. GRB 080319A: Early RAPTOR optical limits
  67. GRB 080319B: HST observations
  68. GRB 080405: Swift-BAT refined analysis
  69. GRB 080405: Swift-XRT position
  70. GRB 080405: Mars Oddysey and Swift-BAT detection, possible host galaxy
  71. GRB 080325: optical upper limit
  72. GRB 080328: GAO 150cm telescope Optical Observation
  73. GRB080330: Improved Swift XRT Position
  74. GRB080328, RIMOTS optical upper limit
  75. GRB 080330: REM optical observations
  76. GRB 080330 Swift-UVOT refined analysis
  77. GRB080330: TNT optical observations
  78. GRB 080330, Swift-BAT refined analysis
  79. GRB 080330: GROND Observations
  80. GRB 080330A: PAIRITEL Infrared Detections
  81. GRB 080330: error in reported XRT position
  82. GRB080330 - SDSS Pre-Burst Observations
  83. GRB 080330: Swift detection of a burst with an optical counterpart
  84. GRB 080330: TAROT Calern observatory optical detection
  85. Swift/UVOT observations of GRB080328
  86. GRB080319B, BVRcIc field calibration
  87. GRB 080328: Enhanced Swift-XRT position
  88. GRB 080328: Swift detection of a burst with an optical counterpart
  89. GRB 080325: Subaru detection of NIR afterglow candidate
  90. GRB080310, late-time photometry with LBT
  91. GRB 080325: GROND Observations
  92. GRB 080325: Swift/UVOT Upper Limits
  93. GRB 080325: Early observations from OSN
  94. GRB 080325: NIR afterglow candidate
  95. GRB 080319D: GROND Detection of the Optical Counterpart
  96. GRB 080325: Enhanced Swift-XRT position
  97. GRB 080325: Swift detection of a burst
  98. GRB 080319B: Spitzer Mid-infrared Observations
  99. Radio Detection of GRB 080319B
  100. GRB 080319D: GROND Observations

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