Skip to main content
Due to the lapse in federal government funding, NASA is not updating this website. See the Operations FAQ for GCN impacts.
New! Super-Kamiokande JSON Notices and Schema v4.5.0. See news and announcements

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"

25808 results found.

  1. GRB 080516, SMARTS optical/IR observations
  2. GRB 080516: Swift-XRT Team refined analysis
  3. GRB 080516, Swift-BAT refined analysis
  4. GRB 080516: Enhanced Swift-XRT position
  5. GRB 080516: Swift detection of a burst
  6. Errartum: VLA upper limit on GRB 080507
  7. VLA upper limit on GRB 080705
  8. GRB 080514B : redshift estimation
  9. IPN triangulation of bright GRB 080513
  10. GRB 080515, Swift-BAT refined analysis
  11. GRB 080514B: slow fading behaviour ?
  12. GRB 080514B: Swift-XRT analysis
  13. GRB 080514B, GROND observations
  14. GRB 080515: Swift detection of a burst
  15. GRB 080514B: Afterglow candidate
  16. GRB 080514B: Watcher observations
  17. GRB 080514B: possible AGILE detection at E>50 MeV
  18. GRB 080514B: SuperAGILE/IPN GRB Localization
  19. procesure for GRB Circular
  20. Swift detection of a possible galactic transient
  21. GRB080514: REM NIR & Optical Observations
  22. GRB 080506: NAYUTA Optical Observation
  23. GRB 080507: Suzaku WAM observation of the prompt emission
  24. GRB 080507: Swift XRT analysis confirms the X-ray afterglow
  25. GRB 080507: Keck photometry
  26. GRB 080503: Chandra Observation of X-ray Rebrightening or Flattening
  27. GRB 080503: Hubble Space Telescope Imaging
  28. GRB 080507: Optical Afterglow
  29. GRB 080506:Optical observations from HCT
  30. GRB 080506: VLA radio upper limit
  31. GRB 080507: GRB localization by SuperAGILE
  32. GRB 080506: Swift XRT refined analysis
  33. GRB080506: Swift/UVOT observations
  34. GRB 080506, Swift-BAT refined analysis
  35. GRB080503, RIMOTS optical upper limit
  36. GRB 080506: Observations from NOT
  37. GRB 080506: Enhanced Swift-XRT position
  38. GRB 080506: Swift detection of a burst with optical afterglow
  39. GRB 080503: VLA radio upper limit
  40. GRB 080503: Observations from NOT
  41. GRB 080503: Slow-rise optical AG ?
  42. GRB 080430: TLS imaging one day after the GRB
  43. GRB 080503, Swift-BAT lag and time-resolved spectral analysis
  44. GRB080503 XRT refined analysis
  45. GRB 080503, Swift-BAT refined analysis
  46. GRB 080430
  47. GRB 080503: Enhanced Swift-XRT position
  48. GRB 080503: New candidate afterglow/host in Gemini imaging
  49. GRB 080503: Swift detection of a short burst
  50. GRB080430: Swift/UVOT observations
  51. VLA radio upper limit on GRB 080430
  52. GRB 080430, Swift-BAT refined analysis
  53. GRB 080430: Swift-XRT refined analysis
  54. GRB 080430: Enhanced Swift-XRT position
  55. GRB 080430: Spectroscopy from CAHA
  56. GRB 080430 - SDSS Pre-Burst Observations
  57. GRB 080430: Bootes observation
  58. GRB 080430: Swift detection of a burst with optical afterglow
  59. GRB 080430: TAROT Calern observatory optical observations
  60. GRB 080426: Swift-XRT refined analysis
  61. GRB080426: Swift/UVOT upper limits
  62. GRB 080426: Enhanced Swift-XRT position
  63. GRB 080426, Swift-BAT refined analysis
  64. GRB 080426: Swift detection of a possibly short burst
  65. Possible GRB 080315: XRT non-detection of afterglow
  66. GRB 080320 : Faulkes Telescope North Observations
  67. GRB 080319A : Liverpool and Faulkes Telescopes Observations
  68. GRB 080420A: ROTSE-III Optical Limits on a possible short burst
  69. GRB080310, BVRcIc field calibration
  70. GRB 080413A: Suzaku/WAM and Swift/BAT joint spectral analysis
  71. Swift XRT and UVOT observations of GRB080414
  72. GRB 080319B: Jet Break, Energetics, Supernova
  73. GRB 080413B: Faulkes Telescope South optical afterglow observations
  74. GRB 080413A: Liverpool Telescope and Faulkes Telescope South optical observations
  75. GRB 080413A: Suzaku WAM observation of the prompt emission
  76. GRB 080413B: Suzaku WAM observation of the prompt emission
  77. GRB 080414: RTT150 optical observations
  78. GRB 080414: A long GRB detected by INTEGRAL
  79. VLA radio observations of GRB 080413B
  80. VLA radio observations of GRB 080413A
  81. GRB 080413B: Ep,i-Eiso correlation
  82. GRB080413B
  83. Swift-BAT spectral lag analysis of GRB 080413B
  84. GRB 080413a, SMARTS optical/IR afterglow observations
  85. GRB080413A: Swift/UVOT observations
  86. GRB 080413B, Swift-BAT refined analysis
  87. GRB 080413A: Swift-XRT refined analysis
  88. GRB 080413A, Swift-BAT refined analysis
  89. GRB 080413A Bootes observation
  90. GRB080413B: REM NIR & Optical Observation
  91. GRB 080413B: GROND detection of afterglow in all bands
  92. GRB 080413B: Swift detection of a possibly short burst with optical counterpart
  93. GRB 080413A: REM detection of the NIR Afterglow
  94. GRB 080413: Enhanced Swift-XRT position
  95. GRB 080413: TAROT Calern observatory optical observations
  96. GRB 080413: Swift detection of a burst with an optical afterglow
  97. GRB 080413: ROTSE-III Detection of Optical Counterpart
  98. GRB 080411: Swift/UVOT refined analysis
  99. GRB 080411, Swift-BAT refined analysis
  100. GRB 080411: Swift-XRT Refined Analysis

Advanced

Download all Circulars as a .tar.gz archive:
Looking for U.S. government information and services? Visit USA.gov