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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"

5401 results found.

  1. Short X-ray Transient detected by MAXI/GSC
  2. GRB 100322A: Suzaku WAM observation of the prompt emission
  3. XRF 100315A: MAXI/GSC detection of a short X-ray transient
  4. GRB100305A: Optical upper limits at IAO
  5. GRB 100305A: PAIRITEL NIR Upper Limits
  6. GRB 100302A: Ondrejov 65cm limit
  7. GRB 100302A: Optical observations at Crni Vrh
  8. GRB 100206A: optical observations in Terskol
  9. GRB 100216A: Swift/UVOT Observations
  10. GRB 100206A: WHT candidate afterglow
  11. GRB 100206A: Pre-explosion imaging and host candidate
  12. GRB 100203A Detected in Ground Analysis of BAT Data
  13. Swift/BAT Detects an Outburst from XTE J1901+014
  14. GRB 091221: Enhanced Swift-XRT position
  15. GRB 091221: UVOT Confirmation of an Optical Afterglow
  16. GRB 091221: ROTSE-III Detection of Optical Counterpart
  17. GRB 091208B: MITSuME Okayama Optical Observation
  18. GRB 091202: Optical and NIR observations
  19. GRB 091127: redshift confirmation with X-shooter
  20. Short X-ray Transient Detection by MAXI/GSC
  21. GRB 091126B: Fermi GBM detection
  22. GRB 091130: MASTER observations
  23. GRB 091127: NOT observations
  24. GRB 091117: Swift XRT refined analysis
  25. GRB 091117: XRT source coincident with a DSS galaxy
  26. GRB 091109B: VLT observations
  27. GRB 091109B: Swift detection of a short burst
  28. GRB 091109: BOOTES-3 observations
  29. GRB 091029: GROND Detection of the Optical/NIR Afterglow
  30. GRB 091029: Swift detection of a burst with an optical counterpart
  31. GRB 091003A: Fermi LAT detection
  32. GRB 091003A: Fermi GBM detection
  33. GRB 090927: Swift XRT refined analysis
  34. GRB 090926B: optical object in error circle
  35. GRB 090926B: MAXI GSC detection
  36. GRB 090926B: Swift XRT refined analysis
  37. GRB 090915: Swift-XRT detection of a fading X-ray counterpart
  38. GRB 090912: Swift detection of a burst
  39. GRB 090902B: Faulkes Telescope North observations
  40. GRB 090831B: MITSuME optical upper limits
  41. GRB 090831B, RIMOTS optical upper limits
  42. GRB 090831B: Swift detection of a possible burst
  43. Fermi Gamma-ray Burst Monitor trigger 273123112 is not a GRB
  44. GRB 090814B: Liverpool Telescope Observations
  45. GRB 090814A, RIMOTS optical upper limits
  46. GRB 090813: Liverpool Telescope afterglow confirmation
  47. GRB 090813: P60 Optical Afterglow Confirmation
  48. GRB 090812: Liverpool Telescope afterglow confirmation
  49. GRB 090812: Swift detection of a burst with an optical counterpart
  50. GRB 090809 X-shooter redshift
  51. GRB 090807: MITSuME optical upper limit
  52. GRB 090807: Swift detection of a burst
  53. GRB 090726: GRT Optical Observation
  54. GRB 090727: I-band observations from 1.23m CAHA
  55. GRB 090727: Liverpool Telescope Afterglow Confirmation and Optical Flare
  56. GRB 090727: Liverpool Telescope possible OT candidate
  57. Fermi Gamma-ray Burst Monitor triggers 269935914 through 270021937 are not GRBs
  58. Konus-Wind and Konus-RF observations of GRB 090715B
  59. GRB 090715B: Swift detection of a burst with a possible optical counterpart
  60. GRB 090712: Fermi GBM observation
  61. GRB 090712: Swift detection of a burst
  62. GRB 090708 : Fermi GBM detection
  63. GRB 090708: Early RAPTOR Optical Limits
  64. GRB 090708: ROTSE-III Optical Limits
  65. GRB 090708: Swift detection of a burst
  66. GRB 090703: Fermi GBM detection
  67. GRB 090313: optical observations
  68. GRB 090626: IPN localization
  69. GRB 090625B: GROND upper limits
  70. GRB 090618: RTT150 optical observations
  71. GRB090618: OAA-OAUV Optical observations
  72. GRB 090616: Fermi GBM detection
  73. RXTE Discovery of Pulsations from SGR 0418+5729
  74. GRB 090530: RTT150 Optical Observation
  75. GRB 090531B: GROND observation
  76. GRB 090530: Early RAPTOR Optical Observations
  77. GRB 090529: MITSuME optical observation
  78. GRB 090530: GRT Optical Observation
  79. GRB 090531: GROND upper limits
  80. GRB 090530: PAIRITEL NIR Detections
  81. GRB 090530A: ROTSE-III Detection of Optical Counterpart
  82. GRB 090530: Swift detection of a burst with an optical counterpart
  83. GRB 090516B: Fermi GBM detection
  84. GRB 090418A: optical observation
  85. GRB 090509: Swift detection of a burst
  86. GRB 090323: optical observations
  87. GRB 090429A: ROVOR magnitude limit
  88. GRB 090426: optical observations
  89. GRB 090429D: Fermi GBM detection
  90. GRB 090424: YNAO-GMG observations
  91. GRB 090426: GAO 150cm telescope Optical Observation
  92. GRB 090429B: Swift detection of a burst
  93. GRB 090424: Continued R-band monitoring
  94. GRB 090425: Fermi GBM detection
  95. GRB 090426: Okayama MITSuME optical observation
  96. GRB 090426: TNT confimation of optical counterpart
  97. GRB090424: R-band detection (37.5 hrs post-burst), jet break?
  98. GRB 090422: Fermi GBM observation
  99. GRB 080408A: GAO 150cm telescope Optical Observation
  100. GRB 090422: Liverpool Telescope observations

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