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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"

25805 results found.

  1. GRB 070920A: deep optical observations at the NOT
  2. GRB 071010B: Keck/LRIS Photometry
  3. GRB 071013: TLS Upper Limit
  4. VLA non-detection of GRB 071011
  5. GRB 071013: Optical observations
  6. GRB 071013: optical observations at NOT
  7. GRB 071013, Swift-BAT refined analysis
  8. GRB071010B, BVRcIc field calibration
  9. GRB 20071013: Xinglong TNT optical Upper Limit
  10. GRB 071010C Swift-BAT detection of a burst
  11. GRB 071011: Optical Limit after 13.95hrs
  12. GRB 071010B correction to GCN 6892 optical observations
  13. GRB 071011: Swift-XRT refined analysis
  14. VLA non-detection of GRB 071010A
  15. GRB 071011: NAYUTA Optical Observation, correction to GCN6886
  16. GRB 071011: Confirmation of P60 optical afterglow
  17. GRB 071010B: Optical Detection
  18. GRB 071011: Kanazawa Optical limits
  19. GRB 071011: P60 Optical Afterglow Candidate
  20. GRB 071011: MARGE Optical Limits
  21. GRB 071010B: Super-LOTIS upper limit
  22. GRB 071010B optical photometry
  23. GRB 071011: XRT afterglow detection
  24. GRB 071011, Swift-BAT refined analysis
  25. GRB 071010B: Gemini Spectroscopic Observations
  26. GRB 071011: NAYUTA Optical Observation
  27. GRB 071010A: Continued Keck Imaging
  28. GRB 071010B: Bright OT confirmed with TLS
  29. GRB 071011: Swift detection of a burst
  30. Optical Observation: GRB 071010
  31. Optical observations: GRB 071010A
  32. Konus-Wind observation of GRB 071010B
  33. GRB071010B: Swift/XRT detection
  34. GRB 071010B, Swift-BAT refined analysis
  35. GRB 071010A: bright NIR afterglow
  36. GRB 071006, Swift-BAT refined analysis
  37. GRB 071010A: Keck/LRIS Photometry
  38. GRB 071008, Swift-BAT refined analysis
  39. GRB 071010, Swift-BAT refined analysis
  40. GRB 071010 REM NIR observations
  41. GRB 071010: TAROT La Silla observatory detection of the afterglow
  42. GRB 071008: Swift detection of a burst
  43. GRB 071003: XRT refined analysis
  44. GRB070920A: MAGIC telescope GeV observation
  45. Radio detection of GRB 071003 with the VLA
  46. GRB 070810B: further XRT analysis
  47. GRB 071003: Possible rebrightening
  48. GRB 071003 : Lulin R-band observations
  49. GRB 071003: Keck HIRES spectroscopy
  50. GRB 071003, Swift-BAT refined analysis
  51. GRB 071003: P60 Confirmation of Optical Afterglow
  52. GRB 071001: Swift-XRT Team refined analysis
  53. GRB 071001, Swift-BAT refined analysis
  54. Faulkes Telescope South observations of GRB 071001
  55. GRB 071001: Swift detection of a burst
  56. VLA observation of GRB 070923
  57. GRB 070911, SMARTS optical/IR afterglow observations
  58. GRB 070925: Gemini South Imaging
  59. GRB070925: Swift-XRT Position
  60. GRB 070920B: ROTSE-III Early Optical Limits
  61. GRB 070925: a long GRB detected by INTEGRAL
  62. GRB 070923, Swift-BAT refined analysis
  63. GRB 070920B: XRT observations
  64. GRB 070917: Suzaku/WAM observation of the prompt emission
  65. GRB 070920B: TAROT La Silla observatory optical observations
  66. GRB 070920B, Swift-BAT refined analysis
  67. GRB 070911: Swift/BAT and Suzaku/WAM joint spectral analysis
  68. GRB 070920B: NOT optical observations
  69. GRB 070920, Swift-BAT refined analysis
  70. GRB 070920: TAROT Calern observatory optical observations
  71. GRB 070917: P60 Observations
  72. Konus-Wind observation of GRB 070917
  73. Swift Status and XRT Calibration Uncertainties
  74. GRB 070917: Swift-XRT observations
  75. GRB 070917: MITSuME Akeno Ic upper limit
  76. GRB 070917: R band observations
  77. GRB 070917, Swift-BAT refined analysis
  78. GRB 070911: Suzaku WAM observation of the prompt emission
  79. GRB 070913: Swift-XRT detection of the possible X-ray afterglow
  80. GRB 070809: The Swift evidence for the SHB nature of this burst
  81. GRB 070913: Afterglow candidate detected by TAROT La Silla observatory
  82. GRB 070913: Swift-BAT refined analysis
  83. GRB 070913: SMARTS optical/IR observations
  84. GRB 070913: TAROT La Silla observatory optical observations
  85. GRB 070911: PAIRITEL IR Observations
  86. GRB 070911: Swift XRT refined analysis
  87. GRB 070911, Swift-BAT refined analysis
  88. Intense burst from SGR 1806-20 detected on September 7
  89. GRB 070809: Confirmation of optical transient
  90. Candidate Orphan GRB Optical Transient in IC 4779
  91. Las Campanas observations of possible TAROT GRB transient near IC
  92. Orphan GRB candidate in IC 4779 at TAROT La Silla observatory
  93. GRB 070824 - Combined SuperAGILE/IPN Localization
  94. GRB 070731: Swift/UVOT Upper Limit
  95. GRB 070805: UVOT afterglow candidate retraction
  96. GRB 070810B : Faulkes Telescope South Observations
  97. GRB 070810A: Continued Keck Imaging
  98. GRB 070810B: Keck spectroscopy of possible host galaxies
  99. GRB070810B: Swift/UVOT Upper Limits
  100. GRB 070810B: XRT refined analysis

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