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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"

2722 results found.

  1. GRB 110328A / Swift J164449.3+573451: X-ray analysis and a mini-blazar analogy
  2. GRB 110328A / Swift J164449.3+573451: NOT optical observations.
  3. GRB 110319A: Swift-XRT refined Analysis
  4. GRB 110305A: Swift detection of a burst
  5. GRB 110223A: Liverpool Telescope observations
  6. OT 110215: possible GRB from 2MASS J00264184+8324093
  7. GRB 110213B: Possible Host Galaxy in SDSS Stripe 82 Imaging
  8. GRB 110213B: P60 Optical Afterglow Candidate
  9. GRB 110212A: Swift XRT and UVOT observations
  10. GRB 110213B: Swift XRT observation
  11. GRB 110213B: MAXI/GSC refined analysis
  12. GRB 110213B: MAXI/GSC detection of a probable GRB
  13. GRB 110210A: Swift detection of a burst
  14. GRB 110207A: Swift-BAT refined analysis
  15. GRB 110205A: Possible Lick/Kast redshift
  16. GRB 110128A: Swift detection of a burst
  17. GRB 101225A: CQUEAN optical observation
  18. GRB 110107A: Swift-XRT afterglow confirmation
  19. Short GRB 110106A: MASTER OT observations
  20. GRB 110106B: Gemini-North / WHT detection of a fading afterglow
  21. GRB 110106B: WHT candidate afterglow
  22. GRB101224A: MITSuME Okayama optical upper limits
  23. IPN triangulation of bright GRB 101123A
  24. GGRB 101023A: GROND detection of the optical-NIR afterglow
  25. GRB 101017A: Swift detection of a burst with optical counterpart
  26. Konus-Wind observation of GRB 101014A
  27. GRB 101014A: Fermi GBM detection
  28. MAXI J1659-152: Swift-BAT refined analysis (triggers 434928 and 434931)
  29. GRB 100915A: TAROT Calern observatory optical observations
  30. GRB 100901A: TLS observations, SDSS calibration, decay slope
  31. Konus-Wind observation of GRB 100829A
  32. GRB 100901A: optical observation at Mt.Terskol
  33. GRB 100901A: optical observation at Mt.Terskol
  34. GRB 100901A: MASTER Optical Early Limits
  35. GRB 100823A: optical observations
  36. GRB 100807A: P200 Infrared Observations
  37. GRB 100807A: P60 Optical Afterglow Discovery
  38. GRB 100805A: Swift detection of a burst with an optical counterpart
  39. GRB 100802A: NOT optical observation
  40. GRB 100802A: ROTSE-III Optical Limits
  41. GRB 100802A: Possible Swift/UVOT Detection of Optical Afterglow
  42. GRB 100727A: Swift/UVOT Upper Limits
  43. GRB 100718A: MASTER-Net optical prompt and alert observations
  44. GRB 100702A: Swift detection of a short burst
  45. Swift-BAT trigger 426048 is not a burst
  46. GRB 100513A: CrAO optical observations
  47. GRB 100526A: NOT optical upper limit
  48. GRB 100510A: MAXI/GSC detection
  49. GRB 100418A: Terskol optical observations
  50. GRB 100425A: Swift detection of a burst
  51. Swift Trigger 420256: ROTSE-III Optical Limits
  52. GRB 100420A: Swift detection of a burst
  53. GRB 100316C: BOOTES-3 observations
  54. GRB 100316D: Swift detection of a burst
  55. GRB 100316A: Enhanced Swift-XRT position
  56. GRB 100316B: Swift detection of a burst with optical counterpart
  57. GRB 100316A: Swift-XRT detection
  58. GRB100219A Akeno and Okayama MITSuME Optical Observation
  59. GRB 100203A Detected in Ground Analysis of BAT Data
  60. GRB 100122A: Fermi GBM detection
  61. Konus-Wind observation of GRB 091208A
  62. GRB 091208B, RIMOTS optical upper limits
  63. Short X-ray Transient Detection by MAXI/GSC
  64. GRB 091130: MASTER observations
  65. GRB 091120: MAXI GSC detection
  66. GRB 091117A: Swift/UVOT followup observations
  67. GRB 091024: optical observations
  68. GRB 091018: GROND observations
  69. GRB 091010 optical upper limits
  70. GRB090829: Fermi GBM Detection
  71. GRB 090817: aphotometry of USNO-B1.0 341-0096763
  72. GRB 090813: P60 Optical Afterglow Confirmation
  73. Swift trigger 358760 is probably a noise event
  74. GRB 090728: Swift detection of a burst
  75. IPN Triangulation of bright GRB 090720B
  76. GRB 090715B: VLA radio detection
  77. GRB 090717: Fermi GBM detection
  78. GRB090709A : WSRT Radio observation
  79. GRB 090704: Fermi GBM observation
  80. GRB 090704: a long GRB found in INTEGRAL off-line analysis
  81. GRB 090706: Fermi GBM detection
  82. GRB 090621B: GRT Optical Observation
  83. GRB 090618 : WSRT radio detection
  84. VLA radio detection of GRB 090618
  85. GRB 090424: WSRT Radio Observations
  86. GRB 090607: Swift detection of a burst
  87. GRB 090529C: Fermi GBM detection
  88. GRB 090529: MITSuME optical observation
  89. GRB 090531B: ROTSE-III Optical Limits
  90. GRB 090531: GROND upper limits
  91. GRB 090531: P60 Observations
  92. GRB 090531: Swift detection of a burst
  93. GRB 090530: GRAS002 optical observations
  94. GRB 090515: KAIT optical upper limits
  95. GRB 090510B: Fermi GBM detection
  96. GRB 090426: optical observations
  97. GRB 090426: R-band limit
  98. GRB 090426: Swift detection of a burst with an optical counterpart
  99. GRB 090424: Liverpool Telescope observations
  100. GRB 090423 limiting magnitudes

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