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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"

4716 results found.

  1. GRB 100513A: CrAO optical observations
  2. Konus-Wind observation of GRB 100522A
  3. GRB100522A: Suzaku WAM observation of the prompt emission
  4. GRB 100522A: Fermi GBM observation
  5. GRB 100522A: Swift detection of a burst
  6. GRB 100513A: PAIRITEL NIR afterglow candidate
  7. GRB100503A: Suzaku WAM observation of the prompt emission
  8. GRB 100503A: Fermi GBM detection
  9. GRB 100424A: PAIRITEL NIR Upper Limits
  10. Swift Trigger 420256: BOOTES-2 observations
  11. Swift Trigger 420256: ROTSE-III Optical Limits
  12. GRB100420A: MITSuME optical upper limits
  13. GRB 100414A: GROND Detection of the Optical Afterglow
  14. GRB 100413: xinglong TNT optical upper limit
  15. INTEGRAL trigger 5994 / GRB 100331A: GROND detection of a variable source
  16. Short X-ray Transient detected by MAXI/GSC
  17. GRB 100322A: Suzaku WAM observation of the prompt emission
  18. XRF 100315A: MAXI/GSC detection of a short X-ray transient
  19. GRB100305A: Optical upper limits at IAO
  20. GRB 100305A: PAIRITEL NIR Upper Limits
  21. GRB 100302A: Ondrejov 65cm limit
  22. GRB 100302A: Optical observations at Crni Vrh
  23. GRB 100206A: optical observations in Terskol
  24. GRB 100216A: Swift/UVOT Observations
  25. GRB 100206A: WHT candidate afterglow
  26. GRB 100206A: Pre-explosion imaging and host candidate
  27. GRB 100203A Detected in Ground Analysis of BAT Data
  28. Swift/BAT Detects an Outburst from XTE J1901+014
  29. GRB 091221: Enhanced Swift-XRT position
  30. GRB 091221: UVOT Confirmation of an Optical Afterglow
  31. GRB 091221: ROTSE-III Detection of Optical Counterpart
  32. GRB 091208B: MITSuME Okayama Optical Observation
  33. GRB 091202: Optical and NIR observations
  34. GRB 091127: redshift confirmation with X-shooter
  35. Short X-ray Transient Detection by MAXI/GSC
  36. GRB 091126B: Fermi GBM detection
  37. GRB 091130: MASTER observations
  38. GRB 091127: NOT observations
  39. GRB 091117: Swift XRT refined analysis
  40. GRB 091117: XRT source coincident with a DSS galaxy
  41. GRB 091109B: VLT observations
  42. GRB 091109B: Swift detection of a short burst
  43. GRB 091109: BOOTES-3 observations
  44. GRB 091029: GROND Detection of the Optical/NIR Afterglow
  45. GRB 091029: Swift detection of a burst with an optical counterpart
  46. GRB 091003A: Fermi LAT detection
  47. GRB 091003A: Fermi GBM detection
  48. GRB 090927: Swift XRT refined analysis
  49. GRB 090926B: optical object in error circle
  50. GRB 090926B: MAXI GSC detection
  51. GRB 090926B: Swift XRT refined analysis
  52. GRB 090915: Swift-XRT detection of a fading X-ray counterpart
  53. GRB 090912: Swift detection of a burst
  54. GRB 090902B: Faulkes Telescope North observations
  55. GRB 090831B: MITSuME optical upper limits
  56. GRB 090831B, RIMOTS optical upper limits
  57. GRB 090831B: Swift detection of a possible burst
  58. Fermi Gamma-ray Burst Monitor trigger 273123112 is not a GRB
  59. GRB 090814B: Liverpool Telescope Observations
  60. GRB 090814A, RIMOTS optical upper limits
  61. GRB 090813: Liverpool Telescope afterglow confirmation
  62. GRB 090813: P60 Optical Afterglow Confirmation
  63. GRB 090812: Liverpool Telescope afterglow confirmation
  64. GRB 090812: Swift detection of a burst with an optical counterpart
  65. GRB 090809 X-shooter redshift
  66. GRB 090807: MITSuME optical upper limit
  67. GRB 090807: Swift detection of a burst
  68. GRB 090726: GRT Optical Observation
  69. GRB 090727: I-band observations from 1.23m CAHA
  70. GRB 090727: Liverpool Telescope Afterglow Confirmation and Optical Flare
  71. GRB 090727: Liverpool Telescope possible OT candidate
  72. Fermi Gamma-ray Burst Monitor triggers 269935914 through 270021937 are not GRBs
  73. Konus-Wind and Konus-RF observations of GRB 090715B
  74. GRB 090715B: Swift detection of a burst with a possible optical counterpart
  75. GRB 090712: Fermi GBM observation
  76. GRB 090712: Swift detection of a burst
  77. GRB 090708 : Fermi GBM detection
  78. GRB 090708: Early RAPTOR Optical Limits
  79. GRB 090708: ROTSE-III Optical Limits
  80. GRB 090708: Swift detection of a burst
  81. GRB 090703: Fermi GBM detection
  82. GRB 090313: optical observations
  83. GRB 090626: IPN localization
  84. GRB 090625B: GROND upper limits
  85. GRB 090618: RTT150 optical observations
  86. GRB090618: OAA-OAUV Optical observations
  87. GRB 090616: Fermi GBM detection
  88. RXTE Discovery of Pulsations from SGR 0418+5729
  89. GRB 090530: RTT150 Optical Observation
  90. GRB 090531B: GROND observation
  91. GRB 090530: Early RAPTOR Optical Observations
  92. GRB 090529: MITSuME optical observation
  93. GRB 090530: GRT Optical Observation
  94. GRB 090531: GROND upper limits
  95. GRB 090530: PAIRITEL NIR Detections
  96. GRB 090530A: ROTSE-III Detection of Optical Counterpart
  97. GRB 090530: Swift detection of a burst with an optical counterpart
  98. GRB 090516B: Fermi GBM detection
  99. GRB 090418A: optical observation
  100. GRB 090509: Swift detection of a burst

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