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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. AGILE-ACS position for the SGR 1806-20 July 27 burst
  2. GRB 070724B: pseudo-z ~ 1.10 from prompt emission spectrum
  3. GRB 070729: LCO optical imaging
  4. VLA upper limit on short hard burst GRB 070714B
  5. Intense burst from SGR 1806-20 detected on July 27
  6. GRB070729: Swift/UVOT upper limits
  7. GRB 070729: Swift-XRT refined analysis
  8. GRB 070729, Swift-BAT refined analysis
  9. GRB 070729: Magellan NIR Observations
  10. GRB 070724B: P60 Observations
  11. GRB 070729: Swift detection of a short hard burst
  12. GRB 070724B: Swift/UVOT Upper limits
  13. GRB070721A: Swift/UVOT Detection of a Weak Afterglow
  14. GRB 070724B: Swift-XRT afterglow likely candidate
  15. GRB 070721A: optical observations
  16. GRB 070724A: further VLT observations
  17. GRB 070724B: Suzaku WAM observation of the prompt emission
  18. Konus-Wind observation of GRB 070724B
  19. GRB 070724B: Analysis of AGILE gamma-ray data
  20. GRB 070724B: Swift-XRT afterglow candidates
  21. GRB 070724b: First Gamma Ray Burst Localization by SuperAGILE onboard
  22. Four radio sources in Swift-XRT error box of GRB 070724
  23. GRB 070724: optical observations
  24. GRB070724: Host galaxy redshift
  25. GRB 070724: P60 and Gemini Observations
  26. GRB 060814 - Keck host detection and redshift
  27. GRB 070724: IR observations
  28. GRB 070724: Closer association with DSS source
  29. Swift/UVOT refined analysis of GRB070724
  30. GRB 070724: Swift-XRT Team refined analysis
  31. GRB 070724: Pre-Imaging Shows a Source in the XRT Error Circle
  32. Short-Hard GRB070714B: PROMPT Observations
  33. GRB 070724, Swift-BAT refined analysis of a short burst
  34. GRB 070721B: further observations and analysis
  35. GRB 070724: Swift detection of a burst
  36. GRB 070326: Detection of first burst from BAT Slew Survey (BATSS)
  37. GRB 070714B: Keck observations
  38. GRB 070721B: optical observations and proposed redshift
  39. Swift/UVOT observations of GRB070721B optical afterglow.
  40. GRB 070721B, Further Swift-BAT refined analysis
  41. Swift/UVOT Observations of GRB070721A
  42. GRB 070721B : Faulkes Telescope South observations
  43. GRB 070721B: Swift-XRT refined analysis
  44. GRB 070721A : Faulkes Telescope South optical limit
  45. GRB 070721A: Swift/XRT refined analysis
  46. GRB 070721B, Swift-BAT refined analysis
  47. GRB 070721A, Swift-BAT refined analysis
  48. GRB070721B: A bright UVOT candidate
  49. GRB 070721B: Swift detection of a burst
  50. GRB 070721: Swift detection of a possible burst
  51. GRB 070714B: Swift/BAT and Suzaku/WAM joint spectral analysis
  52. GRB 070714B : Suzaku WAM observation of the prompt emission
  53. GRB 070714A: Swift-BAT T_zero
  54. GRB070714B: TNG NIR observations
  55. Erratum : Suzaku WAM observation of GRB 070704
  56. GRB 070714A: Swift/UVOT Upper limits
  57. GRB 070714B: Swift/UVOT Upper Limits
  58. GRB 070714B: Swift-BAT spectral lag for the SHB
  59. GRB 070714B: confirmation of optical afterglow
  60. GRB 070616: No Evidence for I Band Afterglow
  61. GRB 070714A: Swift XRT refined analysis
  62. GRB070714B: Swift-XRT refined analysis
  63. GRB 070707: Swift-XRT follow-up observations
  64. GRB 070714b ("Bastille"): Optical Pre-Imaging (Clarification)
  65. GRB 070714 ("Bastille"): Optical Pre-Imaging
  66. GRB 070714B, Swift-BAT refined analysis of the short hard burst
  67. GRB 070714A, Swift-BAT refined analysis
  68. GRB 070714 : Liverpool Telescope optical counterpart ?
  69. GRB 070714: Swift detection of a bright burst, possibly short
  70. Swift detection of a possible burst (Trigger 284850)
  71. SN 2007bg - off-axis GRB?
  72. GRB 070704: RTT150 optical observations
  73. GRB 070704: Suzaku/WAM observation of the prompt emission
  74. Konus-Wind observation of GRB 070707
  75. Updated Swift/UVOT calibration
  76. GRB 070707: optical afterglow
  77. GRB 070707: object inside XRT error circle
  78. Swift/UVOT Observations of GRB070707
  79. Swift XRT observation of GRB 070707
  80. GRB 070707: VLT observations
  81. INTEGRAL GRB 070707 is a short hard burst
  82. INTEGRAL GRB 070707 is a short hard burst
  83. GRB 070707: A long GRB detected by INTEGRAL
  84. GRB 070707: A long GRB detected by INTEGRAL
  85. GRB 070429B: NIR Observations
  86. GRB070704: FAVOR optical observations
  87. GRB 070704 : Liverpool Telescope Observations
  88. GRB 070611: VLT observations
  89. VLA detection of GRB 070612A in C Band
  90. Konus-Wind observation of GRB 070626
  91. GRB 070704: Swift-XRT refined analysis
  92. Swift/UVOT Observations of GRB070704
  93. GRB 070704, Swift-BAT refined analysis
  94. GRB 070704: Correction to GCN Circ 6594
  95. GRB 070704: Swift detection of a burst
  96. GRB 070626: Suzaku/WAM observation of the prompt emission
  97. GRB 070626: IPN localization and Konus spectrum of a bright long burst
  98. GRB 070628 Swift-UVOT Refined Analysis
  99. GRB 070628: NIR detection of afterglow
  100. GRB 070628, Swift-BAT refined analysis

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