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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"
  1. GRB 070913: TAROT La Silla observatory optical observations
  2. GRB 070913: Swift detection of a burst
  3. Swift-BAT Notices back to autonomous real-time distribution
  4. GRB 070911: PAIRITEL IR Observations
  5. GRB 070911: Swift XRT refined analysis
  6. GRB 070911, Swift-BAT refined analysis
  7. GRB 070911: Swift detection of a burst
  8. IPN search for a GRB associated with TAROT transient on August 31
  9. Intense burst from SGR 1806-20 detected on September 7
  10. GRB 070809: Confirmation of optical transient
  11. Observations of possible TAROT GRB transient near IC 4779
  12. Candidate Orphan GRB Optical Transient in IC 4779
  13. GRB 070810b: Image Subtraction of Multiple Keck Observations
  14. Las Campanas observations of possible TAROT GRB transient near IC
  15. Orphan GRB candidate in IC 4779 at TAROT La Silla observatory
  16. Konus-Wind observation of GRB 070824
  17. GRB 070824 - Combined SuperAGILE/IPN Localization
  18. Konus-Wind observation of very bright GRB 070821
  19. GRB 070731: Swift/UVOT Upper Limit
  20. IPN Localization of GRB 070821 (long, very bright)
  21. GRB 070805: UVOT afterglow candidate retraction
  22. GRB070810b: optical candidate
  23. GRB 070810A: ROTSE-III Refined Analysis
  24. Swift observatory off line
  25. GRB 061110A: redshift confirmed
  26. GRB 070810B : Faulkes Telescope South Observations
  27. GRB 070810A: Continued Keck Imaging
  28. GRB 070810B: Keck spectroscopy of possible host galaxies
  29. GRB070810B: Swift/UVOT Upper Limits
  30. GRB 070810B: XRT refined analysis
  31. GRB 070810B, Swift-BAT refined analysis
  32. GRB 070810: MASTER optical observation
  33. GRB 070809: Swift/UVOT Corrected Photometry
  34. Swift Alert 070810.8: MASTER optical observation
  35. Swift Trigger 287421: False trigger due to star tracker loss
  36. GRB 070810A: Swift-BAT refined analysis
  37. GRB 070810B: Xinglong TNT optical Upper Limit
  38. GRB070810B: Optical observations with KANATA
  39. A giant outburst from Cygnus X-1 detected by Konus-Wind and Suzaku-WAM
  40. GRB 070809: Swift/UVOT Upper Limits
  41. GRB 070810B: Swift detection of a short burst
  42. VLA upper limit on the short hard burst GRB 070729
  43. GRB 070810: Keck redshift and photometry
  44. No radio detection in superAGILE burst 070724B
  45. GRB 070809: Keck Imaging
  46. GRB 070810: Swift-XRT Team Refined Analysis
  47. GRB 070809: Swift-XRT refined analysis
  48. GRB 070810: enhanced Swift-XRT position
  49. GRB 070810: Swift/UVOT Optical Counterpart
  50. GRB 070810: ROTSE-III Detection of Optical Counterpart
  51. GRB 070810: Swift detection of a burst
  52. GRB 070809, Swift-BAT refined analysis
  53. GRB 070809: Optical Pre-imaging from Palomar
  54. GRB 070808: Swift/UVOT upper limits
  55. GRB 070809: ROTSE-III Optical 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. GRB 070808: Swift detection of a burst
  67. GRB061121A: PROMPT Observations
  68. GRB070805 XRT and UVOT afterglow candidate
  69. Swift trigger on 4U 1700-377 while star tracker loss-of-lock
  70. GRB070612A: Radio upper limit from GMRT
  71. GRB 070721B: correct afterglow position
  72. Swift/UVOT observations of GRB070805
  73. GRB 070805, Swift-BAT refined analysis
  74. GRB 070805: Swift XRT initial analysis.
  75. GRB 070805: Swift/UVOT initial analysis
  76. GRB 070805: Swift detection of a burst
  77. UVOT observations of SAXJ1810.8-2609
  78. Swift detection of a outburst from SAX J1810.8-2609
  79. VLA non-detection of GRB 070721B
  80. GRB 070802: REM optical observations
  81. GRB 070724B: Swift-XRT afterglow confirmation
  82. GRB 070802: Swift-XRT refined analysis
  83. GRB070802: Swift/UVOT upper limits
  84. GRB 070802: Confirmation of the optical afterglow
  85. GRB 070802, Swift-BAT refined analysis
  86. GRB 070802: VLT redshift
  87. GRB 070802: refined Swift XRT position
  88. GRB 070802: V-band detection of the candidate afterglow
  89. GRB 070802: LCO I-band candidate
  90. GRB 070802: GROND J band candidate
  91. GRB 070802: LCO optical observations
  92. GRB 070802: Swift detection of a burst
  93. GRB 070731, Swift-BAT refined analysis
  94. Konus-A observation of GRB 070729
  95. Swift/UVOT detection of GRB070714B
  96. AGILE-ACS position for the SGR 1806-20 July 27 burst
  97. GRB 070724B: pseudo-z ~ 1.10 from prompt emission spectrum
  98. GRB 070729: LCO optical imaging
  99. VLA upper limit on short hard burst GRB 070714B
  100. Intense burst from SGR 1806-20 detected on July 27

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