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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"

32544 results found.

  1. GRB 070920b: LCO optical observations
  2. GRB 070920B, Swift-BAT refined analysis
  3. GRB 070911: Swift/BAT and Suzaku/WAM joint spectral analysis
  4. GRB 070920, Swift-BAT refined analysis
  5. SGR1806-20: Swift-BAT detection of enhanced activity
  6. GRB070917: Confirmation of optical afterglow
  7. GRB920925C: search for host galaxy
  8. GRB070917: optical observations
  9. GRB 070917: P60 Observations
  10. Konus-Wind observation of GRB 070917
  11. Swift Status and XRT Calibration Uncertainties
  12. GRB 070917: Swift-XRT observations
  13. GRB 070917: KAIT optical limits
  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: Swift-BAT refined analysis
  21. GRB 070913: Corrected BAT position
  22. GRB 070913: SMARTS optical/IR observations
  23. GRB 070911: PAIRITEL IR Observations
  24. GRB 070911: Swift XRT refined analysis
  25. GRB 070911, Swift-BAT refined analysis
  26. IPN search for a GRB associated with TAROT transient on August 31
  27. Intense burst from SGR 1806-20 detected on September 7
  28. GRB 070809: Confirmation of optical transient
  29. Observations of possible TAROT GRB transient near IC 4779
  30. GRB 070810b: Image Subtraction of Multiple Keck Observations
  31. Las Campanas observations of possible TAROT GRB transient near IC
  32. Konus-Wind observation of GRB 070824
  33. Konus-Wind observation of very bright GRB 070821
  34. GRB 070731: Swift/UVOT Upper Limit
  35. GRB 070805: UVOT afterglow candidate retraction
  36. GRB070810b: optical candidate
  37. GRB 070810A: ROTSE-III Refined Analysis
  38. GRB 061110A: redshift confirmed
  39. GRB 070810B : Faulkes Telescope South Observations
  40. GRB 070810A: Continued Keck Imaging
  41. GRB 070810B: Keck spectroscopy of possible host galaxies
  42. GRB070810B: Swift/UVOT Upper Limits
  43. GRB 070810B: XRT refined analysis
  44. GRB 070810B, Swift-BAT refined analysis
  45. GRB 070809: Swift/UVOT Corrected Photometry
  46. Swift Trigger 287421: False trigger due to star tracker loss
  47. GRB 070810A: Swift-BAT refined analysis
  48. GRB 070810B: Xinglong TNT optical Upper Limit
  49. GRB070810B: Optical observations with KANATA
  50. GRB 070809: Swift/UVOT Upper Limits
  51. VLA upper limit on the short hard burst GRB 070729
  52. GRB 070810: Keck redshift and photometry
  53. No radio detection in superAGILE burst 070724B
  54. GRB 070809: Keck Imaging
  55. GRB 070810: Swift-XRT Team Refined Analysis
  56. GRB 070809: Swift-XRT refined analysis
  57. GRB 070810: Swift/UVOT Optical Counterpart
  58. GRB 070809, Swift-BAT refined analysis
  59. GRB 070809: Optical Pre-imaging from Palomar
  60. GRB 070808: Swift/UVOT upper limits
  61. GRB 070809: ROTSE-III Optical Limits
  62. GRB 070808 : Faulkes Telescope South Observations
  63. GCN Swift XRT update position notices and enhanced position circulars
  64. GRB 070808: Swift XRT refined analysis
  65. GRB 070808, Swift-BAT refined analysis
  66. GRB 070808: OPTIMA-Burst optical upper limit
  67. GRB 070808: Xinglong TNT optical Upper Limit
  68. GRB070808: Optical observations with KANATA
  69. GRB 070808: ROTSE-III Optical Limits
  70. GRB061121A: PROMPT Observations
  71. GRB070805 XRT and UVOT afterglow candidate
  72. GRB070612A: Radio upper limit from GMRT
  73. GRB 070721B: correct afterglow position
  74. Swift/UVOT observations of GRB070805
  75. GRB 070805, Swift-BAT refined analysis
  76. GRB 070805: Swift XRT initial analysis.
  77. UVOT observations of SAXJ1810.8-2609
  78. VLA non-detection of GRB 070721B
  79. GRB 070802: REM optical observations
  80. GRB 070724B: Swift-XRT afterglow confirmation
  81. GRB 070802: Swift-XRT refined analysis
  82. GRB070802: Swift/UVOT upper limits
  83. GRB 070802: Confirmation of the optical afterglow
  84. GRB 070802, Swift-BAT refined analysis
  85. GRB 070802: VLT redshift
  86. GRB 070802: refined Swift XRT position
  87. GRB 070802: V-band detection of the candidate afterglow
  88. GRB 070802: LCO I-band candidate
  89. GRB 070802: GROND J band candidate
  90. GRB 070802: LCO optical observations
  91. GRB 070802: Swift detection of a burst
  92. Konus-A observation of GRB 070729
  93. Swift/UVOT detection of GRB070714B
  94. AGILE-ACS position for the SGR 1806-20 July 27 burst
  95. GRB 070729: LCO optical imaging
  96. VLA upper limit on short hard burst GRB 070714B
  97. Intense burst from SGR 1806-20 detected on July 27
  98. GRB070729: Swift/UVOT upper limits
  99. GRB 070729: Swift-XRT refined analysis
  100. GRB 070729, Swift-BAT refined analysis

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