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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"

23404 results found.

  1. GRB 071010B: Swift detection of a burst
  2. GRB 071010 REM NIR observations
  3. GRB 071010: TAROT La Silla observatory detection of the afterglow
  4. GRB 071010: Swift detection of a burst
  5. GRB071008: IAC80 observation
  6. GRB 071008: Swift detection of a burst
  7. Radio detection of GRB 071003 with the VLA
  8. GRB 070810B: further XRT analysis
  9. GRB 071003: Possible rebrightening
  10. GRB 071003 : Lulin R-band observations
  11. GRB 071003: OA power-law decay indices from KAIT
  12. GRB 071003: Keck HIRES spectroscopy
  13. GRB 071003: MARGE Observations
  14. GRB 071003: P60 Confirmation of Optical Afterglow
  15. GRB 071003: Swift detection of a bright burst
  16. GRB 071001, Swift-BAT refined analysis
  17. Faulkes Telescope South observations of GRB 071001
  18. GRB 071001: Swift detection of a burst
  19. VLA observation of GRB 070923
  20. GRB 070911, SMARTS optical/IR afterglow observations
  21. GRB070925: Swift-XRT Afterglow confirmation
  22. GRB 070925: Gemini South Imaging
  23. GRB 070920B: ROTSE-III Early Optical Limits
  24. GRB 070920B: XRT observations
  25. GRB 070923: Swift detection of a short hard burst
  26. GRB 070920B: TAROT La Silla observatory optical observations
  27. GRB 070920B: NOT optical observations
  28. GRB 070920B: Swift detection of a burst
  29. GRB 070920: TAROT Calern observatory optical observations
  30. GRB 070920: Swift detection of a burst
  31. SGR1806-20: Swift-BAT detection of enhanced activity
  32. GRB070917: optical observations
  33. GRB 070917: P60 Observations
  34. Swift Status and XRT Calibration Uncertainties
  35. GRB 070917: MITSuME Akeno Ic upper limit
  36. GRB 070917: R band observations
  37. GRB 070917: Swift detection of a bright burst
  38. GRB 070913: Swift-XRT detection of the possible X-ray afterglow
  39. GRB 070809: The Swift evidence for the SHB nature of this burst
  40. GRB 070913: Corrected BAT position
  41. GRB 070913: SMARTS optical/IR observations
  42. GRB 070913: TAROT La Silla observatory optical observations
  43. GRB 070913: Swift detection of a burst
  44. Swift-BAT Notices back to autonomous real-time distribution
  45. GRB 070911: PAIRITEL IR Observations
  46. GRB 070911, Swift-BAT refined analysis
  47. Intense burst from SGR 1806-20 detected on September 7
  48. GRB 070809: Confirmation of optical transient
  49. Candidate Orphan GRB Optical Transient in IC 4779
  50. Las Campanas observations of possible TAROT GRB transient near IC
  51. Orphan GRB candidate in IC 4779 at TAROT La Silla observatory
  52. GRB 070824 - Combined SuperAGILE/IPN Localization
  53. GRB 070731: Swift/UVOT Upper Limit
  54. IPN Localization of GRB 070821 (long, very bright)
  55. GRB 070805: UVOT afterglow candidate retraction
  56. GRB070810b: optical candidate
  57. GRB 070810B : Faulkes Telescope South Observations
  58. GRB 070810A: Continued Keck Imaging
  59. GRB 070810B: Keck spectroscopy of possible host galaxies
  60. GRB070810B: Swift/UVOT Upper Limits
  61. GRB 070810B: XRT refined analysis
  62. GRB 070809: Swift/UVOT Corrected Photometry
  63. GRB 070810B: Xinglong TNT optical Upper Limit
  64. GRB070810B: Optical observations with KANATA
  65. A giant outburst from Cygnus X-1 detected by Konus-Wind and Suzaku-WAM
  66. GRB 070809: Swift/UVOT Upper Limits
  67. GRB 070810B: Swift detection of a short burst
  68. VLA upper limit on the short hard burst GRB 070729
  69. No radio detection in superAGILE burst 070724B
  70. GRB 070809: Keck Imaging
  71. GRB 070810: Swift-XRT Team Refined Analysis
  72. GRB 070809: Swift-XRT refined analysis
  73. GRB 070810: enhanced Swift-XRT position
  74. GRB 070810: Swift/UVOT Optical Counterpart
  75. GRB 070810: ROTSE-III Detection of Optical Counterpart
  76. GRB 070810: Swift detection of a burst
  77. GRB 070809: Optical Pre-imaging from Palomar
  78. GRB 070808: Swift/UVOT upper limits
  79. GRB 070809: ROTSE-III Optical Limits
  80. GRB 070809: Swift detection of a short burst
  81. GRB 070808 : Faulkes Telescope South Observations
  82. GCN Swift XRT update position notices and enhanced position circulars
  83. GRB 070808: Swift XRT refined analysis
  84. GRB 070808, Swift-BAT refined analysis
  85. GRB 070808: OPTIMA-Burst optical upper limit
  86. GRB 070808: Xinglong TNT optical Upper Limit
  87. GRB070808: Optical observations with KANATA
  88. GRB070808 - SDSS Pre-Burst Observations
  89. GRB 070808: ROTSE-III Optical Limits
  90. GRB 070808: Swift detection of a burst
  91. GRB061121A: PROMPT Observations
  92. GRB070805 XRT and UVOT afterglow candidate
  93. GRB070612A: Radio upper limit from GMRT
  94. Swift/UVOT observations of GRB070805
  95. GRB 070805: Swift detection of a burst
  96. UVOT observations of SAXJ1810.8-2609
  97. Swift detection of a outburst from SAX J1810.8-2609
  98. VLA non-detection of GRB 070721B
  99. GRB 070802: REM optical observations
  100. GRB 070802: Swift-XRT refined analysis

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