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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"

5833 results found.

  1. GRB 100316D: Swift detection of a burst
  2. GRB 100305A: P60 Observations
  3. GRB 100305A: Swift detection of a burst
  4. GRB 100302A: Swift detection of a burst
  5. GRB 100206A: optical observations in CrAO
  6. GRB 100206A: optical observations in Terskol
  7. GRB 100213B: Swift detection of a burst
  8. GRB 100212A: Swift detection of a burst
  9. GRB 100205A: Keck limits on an underlying host galaxy
  10. GRB 100206A: WHT candidate afterglow
  11. GRB 100206A: Enhanced Swift-XRT position
  12. GRB 100206A: Pre-explosion imaging and host candidate
  13. GRB 100206A: Swift detection of a short hard burst
  14. GRB 100113A: Fermi GBM detection
  15. GRB 100205A Gemini-North IR afterglow candidate
  16. GRB 100205A: Gemini-South Observations
  17. GRB 100205A: NOT optical observations
  18. Short X-ray Transient detected by MAXI/GSC
  19. GRB 100119A: Swift detection of a burst
  20. GRB 100117A: Swift detection of a short hard burst
  21. GRB 091221: Swift detection of a burst
  22. GRB 091208A: GAO 150cm telescope Optical Observation
  23. GRB 091208B: GAO 150cm telescope Optical Observation
  24. GRB 091208B: GROND observations
  25. GRB 091208B: Fermi GBM observation
  26. GRB 091208A, RIMOTS optical upper limits
  27. GRB 091208B: MITSuME Akeno Optical Observation
  28. GRB 091208B: MITSuME Okayama Optical Observation
  29. GRB 091208B, RIMOTS optical upper limits
  30. GRB 091208B: Swift detection of a burst with an optical afterglow
  31. GRB 091208B: BOOTES-3 optical afterglow
  32. GRB 091208: ROTSE-III Optical Limits
  33. GRB 091202: GTC & CAHA optical/nIR afterglow candidate
  34. GRB 091202 - UVOT-enhanced XRT position
  35. GRB 091126B: Fermi GBM detection
  36. GRB 091130B: Swift detection of a burst
  37. GRB 091127: NOT observations
  38. GRB 091109B: Suzaku WAM observation of the prompt emission
  39. GRB 091109: Faulkes Telescope South observations
  40. GRB 091109: Enhanced Swift-XRT position
  41. GRB091109: REM detection of the NIR afterglow
  42. GRB 091109: Swift detection of a burst with optical afterglow
  43. GRB 091104: Swift detection of a burst
  44. GRB 091029: Swift detection of a burst with an optical counterpart
  45. A mistake in testing a new function in Swift
  46. GRB 091026: Swift detection of a Gamma Ray Burst
  47. GRB 091024: Fermi GBM Observations
  48. GRB 091024: Swift-XRT team refined analysis
  49. GRB 091024: GRAS004 optical observations
  50. GRB 091020: Swift detection of a burst with an optical afterglow
  51. GRB 091018: miniTAO/ANIR Observations
  52. GRB 091010: optical obsevation
  53. GRB 091010: optical afterglow candidate rejection
  54. GRB 091010: RXTE detection
  55. GRB 090910: SuperAGILE Localization of a Long GRB
  56. GRB 090929B: Suzaku WAM observation of the prompt emission
  57. Konus-Wind observation of GRB 090929B
  58. GRB 090929B: Swift detection of a burst
  59. GRB 090926B: Swift detection of a burst
  60. GRB 090925: Fermi GBM detection
  61. GRB 090915: Swift-XRT detection of a fading X-ray counterpart
  62. GRB 090823: Swift XRT confirmation of the X-ray afterglow
  63. GRB 090904A: ROTSE-III Optical Limits
  64. GRB 090904: Swift detection of a burst
  65. GRB 090902B: GROND NIR Afterglow Observations
  66. GRB 090902: Fermi GBM detection
  67. GRB 090831B: MITSuME optical upper limits
  68. GRB 090831: MAXI GSC detection
  69. GRB 090831: Fermi GBM detection
  70. GRB 090826: Fermi GBM detection
  71. GRB 090817: No host galaxy, no supernova
  72. GRB 090817: aphotometry of USNO-B1.0 341-0096763
  73. Fermi Gamma-ray Burst Monitor trigger 271934815 is not a GRB
  74. GRB 090814A, RIMOTS optical upper limits
  75. GRB 090814: Swift detection of a burst
  76. GRB 090812: P60 Confirmation of Optical Afterglow
  77. GRB 090812: Swift detection of a burst with an optical counterpart
  78. GRB 090809 X-shooter redshift
  79. GRB 090807: Swift detection of a burst
  80. GRB 090709A : Quick look analysis of the Suzaku observation
  81. GRB 090711: Fermi GBM detection
  82. Fermi Gamma-ray Burst Monitor triggers 269935914 through 270021937 are not GRBs
  83. GRB 090715B: break in the optical afterglow decay
  84. GRB 090709B: Fermi GBM detection
  85. GRB 090709A: Wyoming Infrared Observatory NIR upper limits
  86. GRB 090626: Suzaku WAM observation of the prompt emission
  87. GRB 090709: PAIRITEL NIR Upper Limits
  88. GRB 090529: CrAO optical upper limit
  89. GRB 090529: Mt.Terskol optical observations
  90. GRB 090313: optical observations
  91. GRB 090630: Fermi GBM detection
  92. GRB 090625B: Swift observation of the INTEGRAL GRB 090625B
  93. GRB 090620: Fermi GBM detecion
  94. GRB 090618: LOAO R-band Observation
  95. GRB 090529A: RTT150 Optical Observations
  96. GRB 090528: Suzaku WAM observation of the prompt emission
  97. GRB 090528: Fermi GBM detection
  98. GRB 090529: optical observations
  99. GRB 090529: TLS Afterglow Observations
  100. GRB090529: UVOT/Swift detection of a brightening optical afterglow

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