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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"

25778 results found.

  1. GRB 071001, Swift-BAT refined analysis
  2. Faulkes Telescope South observations of GRB 071001
  3. GRB 071001: Swift detection of a burst
  4. VLA observation of GRB 070923
  5. GRB 070911, SMARTS optical/IR afterglow observations
  6. GRB 070925: Gemini South Imaging
  7. GRB070925: Swift-XRT Position
  8. GRB 070920B: ROTSE-III Early Optical Limits
  9. GRB 070925: a long GRB detected by INTEGRAL
  10. GRB 070920B: TAROT La Silla observatory optical observations
  11. GRB 070911: Swift/BAT and Suzaku/WAM joint spectral analysis
  12. GRB 070920B: NOT optical observations
  13. GRB 070920: TAROT Calern observatory optical observations
  14. SGR1806-20: Swift-BAT detection of enhanced activity
  15. GRB920925C: search for host galaxy
  16. GRB 070917: P60 Observations
  17. Konus-Wind observation of GRB 070917
  18. Swift Status and XRT Calibration Uncertainties
  19. GRB 070917: Swift-XRT observations
  20. GRB 070917: MITSuME Akeno Ic upper limit
  21. GRB 070917: R band observations
  22. GRB 070911: Suzaku WAM observation of the prompt emission
  23. GRB 070913: Swift-XRT detection of the possible X-ray afterglow
  24. GRB 070809: The Swift evidence for the SHB nature of this burst
  25. GRB 070913: SMARTS optical/IR observations
  26. GRB 070913: TAROT La Silla observatory optical observations
  27. GRB 070911: PAIRITEL IR Observations
  28. GRB 070911: Swift XRT refined analysis
  29. IPN search for a GRB associated with TAROT transient on August 31
  30. Intense burst from SGR 1806-20 detected on September 7
  31. GRB 070809: Confirmation of optical transient
  32. Candidate Orphan GRB Optical Transient in IC 4779
  33. Las Campanas observations of possible TAROT GRB transient near IC
  34. Orphan GRB candidate in IC 4779 at TAROT La Silla observatory
  35. Konus-Wind observation of GRB 070824
  36. GRB 070824 - Combined SuperAGILE/IPN Localization
  37. Konus-Wind observation of very bright GRB 070821
  38. GRB 070731: Swift/UVOT Upper Limit
  39. GRB 070805: UVOT afterglow candidate retraction
  40. Swift observatory off line
  41. GRB 070810B : Faulkes Telescope South Observations
  42. GRB 070810A: Continued Keck Imaging
  43. GRB 070810B: Keck spectroscopy of possible host galaxies
  44. GRB070810B: Swift/UVOT Upper Limits
  45. GRB 070810B: XRT refined analysis
  46. GRB 070810B: Xinglong TNT optical Upper Limit
  47. GRB070810B: Optical observations with KANATA
  48. A giant outburst from Cygnus X-1 detected by Konus-Wind and Suzaku-WAM
  49. GRB 070809: Swift/UVOT Upper Limits
  50. VLA upper limit on the short hard burst GRB 070729
  51. No radio detection in superAGILE burst 070724B
  52. GRB 070809: Keck Imaging
  53. GRB 070810: Swift-XRT Team Refined Analysis
  54. GRB 070809: Swift-XRT refined analysis
  55. GRB 070810: enhanced Swift-XRT position
  56. GRB 070810: Swift/UVOT Optical Counterpart
  57. GRB 070808: Swift/UVOT upper limits
  58. GRB 070809: Swift detection of a short burst
  59. GRB 070808 : Faulkes Telescope South Observations
  60. GCN Swift XRT update position notices and enhanced position circulars
  61. GRB 070808: Swift XRT refined analysis
  62. GRB 070808: OPTIMA-Burst optical upper limit
  63. GRB 070808: Xinglong TNT optical Upper Limit
  64. GRB070808: Optical observations with KANATA
  65. GRB070808 - SDSS Pre-Burst Observations
  66. GRB 070808: ROTSE-III Optical Limits
  67. GRB070805 XRT and UVOT afterglow candidate
  68. GRB070612A: Radio upper limit from GMRT
  69. GRB 070721B: correct afterglow position
  70. Swift/UVOT observations of GRB070805
  71. GRB 070805: Swift detection of a burst
  72. UVOT observations of SAXJ1810.8-2609
  73. Swift detection of a outburst from SAX J1810.8-2609
  74. VLA non-detection of GRB 070721B
  75. GRB 070802: REM optical observations
  76. GRB 070802: Swift-XRT refined analysis
  77. GRB070802: Swift/UVOT upper limits
  78. GRB 070802: V-band detection of the candidate afterglow
  79. GRB 070802: LCO I-band candidate
  80. GRB 070802: GROND J band candidate
  81. GRB 070802: LCO optical observations
  82. Konus-A observation of GRB 070729
  83. Swift/UVOT detection of GRB070714B
  84. VLA upper limit on short hard burst GRB 070714B
  85. GRB070729: Swift/UVOT upper limits
  86. GRB 070729: Swift-XRT refined analysis
  87. GRB 070724B: P60 Observations
  88. GRB 070724B: Swift/UVOT Upper limits
  89. GRB 070724B: Swift-XRT afterglow likely candidate
  90. GRB 070721A: optical observations
  91. GRB 070724A: further VLT observations
  92. GRB 070724B: Suzaku WAM observation of the prompt emission
  93. Konus-Wind observation of GRB 070724B
  94. GRB 070724B: Swift-XRT afterglow candidates
  95. Four radio sources in Swift-XRT error box of GRB 070724
  96. GRB 070724: P60 and Gemini Observations
  97. GRB 060814 - Keck host detection and redshift
  98. GRB 070724: Closer association with DSS source
  99. Swift/UVOT refined analysis of GRB070724
  100. GRB 070724: Swift-XRT Team refined analysis

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