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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"

25044 results found.

  1. GRB 070923, Swift-BAT refined analysis
  2. GRB 070920B: XRT observations
  3. GRB 070917: Suzaku/WAM observation of the prompt emission
  4. GRB 070920B: TAROT La Silla observatory optical observations
  5. GRB 070920B, Swift-BAT refined analysis
  6. GRB 070911: Swift/BAT and Suzaku/WAM joint spectral analysis
  7. GRB 070920B: NOT optical observations
  8. GRB 070920, Swift-BAT refined analysis
  9. GRB 070920: TAROT Calern observatory optical observations
  10. GRB 070917: P60 Observations
  11. Konus-Wind observation of GRB 070917
  12. Swift Status and XRT Calibration Uncertainties
  13. GRB 070917: Swift-XRT observations
  14. GRB 070917: MITSuME Akeno Ic upper limit
  15. GRB 070917: R band observations
  16. GRB 070917, Swift-BAT refined analysis
  17. GRB 070911: Suzaku WAM observation of the prompt emission
  18. GRB 070913: Swift-XRT detection of the possible X-ray afterglow
  19. GRB 070809: The Swift evidence for the SHB nature of this burst
  20. GRB 070913: Afterglow candidate detected by TAROT La Silla observatory
  21. GRB 070913: Swift-BAT refined analysis
  22. GRB 070913: SMARTS optical/IR observations
  23. GRB 070913: TAROT La Silla observatory optical observations
  24. GRB 070911: PAIRITEL IR Observations
  25. GRB 070911: Swift XRT refined analysis
  26. GRB 070911, Swift-BAT refined analysis
  27. Intense burst from SGR 1806-20 detected on September 7
  28. GRB 070809: Confirmation of optical transient
  29. Candidate Orphan GRB Optical Transient in IC 4779
  30. Las Campanas observations of possible TAROT GRB transient near IC
  31. Orphan GRB candidate in IC 4779 at TAROT La Silla observatory
  32. GRB 070824 - Combined SuperAGILE/IPN Localization
  33. GRB 070731: Swift/UVOT Upper Limit
  34. GRB 070805: UVOT afterglow candidate retraction
  35. GRB 070810B : Faulkes Telescope South Observations
  36. GRB 070810A: Continued Keck Imaging
  37. GRB 070810B: Keck spectroscopy of possible host galaxies
  38. GRB070810B: Swift/UVOT Upper Limits
  39. GRB 070810B: XRT refined analysis
  40. GRB 070810B, Swift-BAT refined analysis
  41. Swift Trigger 287421: False trigger due to star tracker loss
  42. GRB 070810A: Swift-BAT refined analysis
  43. GRB 070810B: Xinglong TNT optical Upper Limit
  44. GRB070810B: Optical observations with KANATA
  45. A giant outburst from Cygnus X-1 detected by Konus-Wind and Suzaku-WAM
  46. GRB 070809: Swift/UVOT Upper Limits
  47. VLA upper limit on the short hard burst GRB 070729
  48. No radio detection in superAGILE burst 070724B
  49. GRB 070809: Keck Imaging
  50. GRB 070810: Swift-XRT Team Refined Analysis
  51. GRB 070809: Swift-XRT refined analysis
  52. GRB 070810: enhanced Swift-XRT position
  53. GRB 070810: Swift/UVOT Optical Counterpart
  54. GRB 070809, Swift-BAT refined analysis
  55. GRB 070808: Swift/UVOT upper limits
  56. GRB 070809: Swift detection of a short burst
  57. GRB 070808 : Faulkes Telescope South Observations
  58. GCN Swift XRT update position notices and enhanced position circulars
  59. GRB 070808: Swift XRT refined analysis
  60. GRB 070808, Swift-BAT refined analysis
  61. GRB 070808: OPTIMA-Burst optical upper limit
  62. GRB 070808: Xinglong TNT optical Upper Limit
  63. GRB070808: Optical observations with KANATA
  64. GRB070808 - SDSS Pre-Burst Observations
  65. GRB 070808: ROTSE-III Optical Limits
  66. GRB070805 XRT and UVOT afterglow candidate
  67. GRB070612A: Radio upper limit from GMRT
  68. GRB 070721B: correct afterglow position
  69. Swift/UVOT observations of GRB070805
  70. GRB 070805, Swift-BAT refined analysis
  71. UVOT observations of SAXJ1810.8-2609
  72. Swift detection of a outburst from SAX J1810.8-2609
  73. VLA non-detection of GRB 070721B
  74. GRB 070802: REM optical observations
  75. GRB 070802: Swift-XRT refined analysis
  76. GRB070802: Swift/UVOT upper limits
  77. GRB 070802, Swift-BAT refined analysis
  78. GRB 070802: V-band detection of the candidate afterglow
  79. GRB 070802: GROND J band candidate
  80. GRB 070731, Swift-BAT refined analysis
  81. Konus-A observation of GRB 070729
  82. Swift/UVOT detection of GRB070714B
  83. VLA upper limit on short hard burst GRB 070714B
  84. Intense burst from SGR 1806-20 detected on July 27
  85. GRB070729: Swift/UVOT upper limits
  86. GRB 070729: Swift-XRT refined analysis
  87. GRB 070729, Swift-BAT refined analysis
  88. GRB 070724B: P60 Observations
  89. GRB 070724B: Swift/UVOT Upper limits
  90. GRB 070724B: Swift-XRT afterglow likely candidate
  91. GRB 070721A: optical observations
  92. GRB 070724A: further VLT observations
  93. GRB 070724B: Suzaku WAM observation of the prompt emission
  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. Swift/UVOT refined analysis of GRB070724
  99. GRB 070724: Swift-XRT Team refined analysis
  100. GRB 070724, Swift-BAT refined analysis of a short burst

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