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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"

22111 results found.

  1. GRB 071011: Swift detection of a burst
  2. Optical Observation: GRB 071010
  3. Optical observations: GRB 071010A
  4. GRB071010B: Swift/XRT detection
  5. GRB 071006, Swift-BAT refined analysis
  6. GRB071008: optical observations
  7. GRB 071010A: Keck/LRIS Photometry
  8. GRB 071010B: Swift detection of a burst
  9. GRB 071010 REM NIR observations
  10. GRB 071010: TAROT La Silla observatory detection of the afterglow
  11. GRB 071010: Swift detection of a burst
  12. GRB071008: IAC80 observation
  13. GRB 071008: Swift detection of a burst
  14. Radio detection of GRB 071003 with the VLA
  15. GRB 070810B: further XRT analysis
  16. GRB 071003: Possible rebrightening
  17. GRB 071003 : Lulin R-band observations
  18. GRB 071003: OA power-law decay indices from KAIT
  19. GRB 071003: Keck HIRES spectroscopy
  20. GRB 071003: MARGE Observations
  21. GRB 071003: P60 Confirmation of Optical Afterglow
  22. GRB 071003: Swift detection of a bright burst
  23. GRB 071001, Swift-BAT refined analysis
  24. Faulkes Telescope South observations of GRB 071001
  25. GRB 071001: Swift detection of a burst
  26. VLA observation of GRB 070923
  27. GRB 070911, SMARTS optical/IR afterglow observations
  28. GRB070925: Swift-XRT Afterglow confirmation
  29. GRB 070925: Gemini South Imaging
  30. GRB 070920B: ROTSE-III Early Optical Limits
  31. GRB 070920B: XRT observations
  32. GRB 070923: Swift detection of a short hard burst
  33. GRB 070920B: TAROT La Silla observatory optical observations
  34. GRB 070920B: NOT optical observations
  35. GRB 070920B: Swift detection of a burst
  36. GRB 070920: TAROT Calern observatory optical observations
  37. GRB 070920: Swift detection of a burst
  38. SGR1806-20: Swift-BAT detection of enhanced activity
  39. GRB070917: optical observations
  40. GRB 070917: P60 Observations
  41. Swift Status and XRT Calibration Uncertainties
  42. GRB 070917: MITSuME Akeno Ic upper limit
  43. GRB 070917: R band observations
  44. GRB 070917: Swift detection of a bright burst
  45. GRB 070913: Swift-XRT detection of the possible X-ray afterglow
  46. GRB 070809: The Swift evidence for the SHB nature of this burst
  47. GRB 070913: Corrected BAT position
  48. GRB 070913: SMARTS optical/IR observations
  49. GRB 070913: TAROT La Silla observatory optical observations
  50. GRB 070913: Swift detection of a burst
  51. Swift-BAT Notices back to autonomous real-time distribution
  52. GRB 070911: PAIRITEL IR Observations
  53. GRB 070911, Swift-BAT refined analysis
  54. Intense burst from SGR 1806-20 detected on September 7
  55. GRB 070809: Confirmation of optical transient
  56. Candidate Orphan GRB Optical Transient in IC 4779
  57. Las Campanas observations of possible TAROT GRB transient near IC
  58. Orphan GRB candidate in IC 4779 at TAROT La Silla observatory
  59. GRB 070824 - Combined SuperAGILE/IPN Localization
  60. GRB 070731: Swift/UVOT Upper Limit
  61. IPN Localization of GRB 070821 (long, very bright)
  62. GRB 070805: UVOT afterglow candidate retraction
  63. GRB070810b: optical candidate
  64. GRB 070810B : Faulkes Telescope South Observations
  65. GRB 070810A: Continued Keck Imaging
  66. GRB 070810B: Keck spectroscopy of possible host galaxies
  67. GRB070810B: Swift/UVOT Upper Limits
  68. GRB 070810B: XRT refined analysis
  69. GRB 070809: Swift/UVOT Corrected Photometry
  70. GRB 070810B: Xinglong TNT optical Upper Limit
  71. GRB070810B: Optical observations with KANATA
  72. A giant outburst from Cygnus X-1 detected by Konus-Wind and Suzaku-WAM
  73. GRB 070809: Swift/UVOT Upper Limits
  74. GRB 070810B: Swift detection of a short burst
  75. VLA upper limit on the short hard burst GRB 070729
  76. No radio detection in superAGILE burst 070724B
  77. GRB 070809: Keck Imaging
  78. GRB 070810: Swift-XRT Team Refined Analysis
  79. GRB 070809: Swift-XRT refined analysis
  80. GRB 070810: enhanced Swift-XRT position
  81. GRB 070810: Swift/UVOT Optical Counterpart
  82. GRB 070810: ROTSE-III Detection of Optical Counterpart
  83. GRB 070810: Swift detection of a burst
  84. GRB 070809: Optical Pre-imaging from Palomar
  85. GRB 070808: Swift/UVOT upper limits
  86. GRB 070809: ROTSE-III Optical Limits
  87. GRB 070809: Swift detection of a short burst
  88. GRB 070808 : Faulkes Telescope South Observations
  89. GCN Swift XRT update position notices and enhanced position circulars
  90. GRB 070808: Swift XRT refined analysis
  91. GRB 070808, Swift-BAT refined analysis
  92. GRB 070808: OPTIMA-Burst optical upper limit
  93. GRB 070808: Xinglong TNT optical Upper Limit
  94. GRB070808: Optical observations with KANATA
  95. GRB070808 - SDSS Pre-Burst Observations
  96. GRB 070808: ROTSE-III Optical Limits
  97. GRB 070808: Swift detection of a burst
  98. GRB061121A: PROMPT Observations
  99. GRB070805 XRT and UVOT afterglow candidate
  100. GRB070612A: Radio upper limit from GMRT

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