Skip to main content
Passing of Scott Barthelmy, GCN Founder 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"
  1. GRB 080503: Slow-rise optical AG ?
  2. GRB 080430: TLS imaging one day after the GRB
  3. GRB 080503: No further optical rebrightening
  4. GRB 080503: Late-time Optical rebrightening (possible mini-SN) - correction
  5. GRB 080503: Late-time Optical rebrightening (possible mini-SN)
  6. GRB 080503, Swift-BAT lag and time-resolved spectral analysis
  7. GRB 080503: MITSuME Ishigakijima optical upper limits
  8. GRB080503: Swift/UVOT Upper Limits
  9. GRB080503 XRT refined analysis
  10. GRB 080503, Swift-BAT refined analysis
  11. GRB 080430
  12. GRB 080430
  13. GRB 080430
  14. GRB 080503: Enhanced Swift-XRT position
  15. GRB 080503: MITSuME Akeno optical upper limits
  16. GRB 080503: New candidate afterglow/host in Gemini imaging
  17. GRB 080503: Optical afterglow candidate and LRIS spectroscopy of the short burst
  18. GRB 080503: Swift detection of a short burst
  19. GRB 080411: Continued Swift Monitoring
  20. GRB 080430: Optical observations
  21. GRB 080430: Shallow decay
  22. GRB080430: RTT150 Optical Observations
  23. GRB080430: Swift/UVOT observations
  24. VLA radio upper limit on GRB 080430
  25. GRB 080430 - multicolor observations of the afterglow
  26. GRB 080430 optical observations
  27. GRB 080430, Swift-BAT refined analysis
  28. GRB080430: optical observations
  29. GRB 080430: Hobby-Eberly Telescope Absorption Redshift
  30. GRB 080430: Swift-XRT refined analysis
  31. GRB 080430: Enhanced Swift-XRT position
  32. GRB080430: Optical observation in AsU CAS Ondrejov & Brno
  33. GRB 080430: Spectroscopy from CAHA
  34. GRB 080430 - SDSS Pre-Burst Observations
  35. GRB 080430: Bootes observation
  36. GRB 080430: Swift detection of a burst with optical afterglow
  37. GRB 080430: TAROT Calern observatory optical observations
  38. GRB960202B - on the association with SN 1996cr
  39. GRB080426: Observations from CAHA
  40. GRB 080426: Swift-XRT refined analysis
  41. GRB080426: Swift/UVOT upper limits
  42. GRB 080426: Enhanced Swift-XRT position
  43. GRB 080426, Swift-BAT refined analysis
  44. GRB 080426: Swift detection of a possibly short burst
  45. Possible GRB 080315: XRT non-detection of afterglow
  46. GRB 080320 : Faulkes Telescope North Observations
  47. GRB 080319A : Liverpool and Faulkes Telescopes Observations
  48. GRB080319A: MAGIC telescope GeV observation
  49. Swift-BAT trigger 309665 is not a GRB
  50. GRB 080420A: ROTSE-III Optical Limits on a possible short burst
  51. GRB 080420?: Swift detection of a possible short burst
  52. GRB080310, BVRcIc field calibration
  53. GRB 080413A: Suzaku/WAM and Swift/BAT joint spectral analysis
  54. GRB 080413B: Rapid PROMPT Observations
  55. Swift XRT and UVOT observations of GRB080414
  56. GRB 080319B: Jet Break, Energetics, Supernova
  57. GRB 080413B: Faulkes Telescope South optical afterglow observations
  58. GRB 080413A: Liverpool Telescope and Faulkes Telescope South optical observations
  59. GRB 080413A: Suzaku WAM observation of the prompt emission
  60. GRB 080413B: Suzaku WAM observation of the prompt emission
  61. GRB 080413A: MOA-II optical afterglow observations
  62. GRB 080319B: Continued Gemini-N monitoring
  63. GRB 080414: RTT150 optical observations
  64. GRB 080414 Watcher observations
  65. GRB 080414: A long GRB detected by INTEGRAL
  66. VLA radio observations of GRB 080413B
  67. GRB 080413A: Gemini-South Spectroscopy
  68. GRB 080413B: Gemini-South Spectroscopy
  69. VLA radio observations of GRB 080413A
  70. IBAS Alert n. 5257 : not a GRB
  71. GRB 080413B: Ep,i-Eiso correlation
  72. GRB080413B
  73. Swift-BAT spectral lag analysis of GRB 080413B
  74. GRB 080413a, SMARTS optical/IR afterglow observations
  75. GRB 080413B: Swift XRT refined analysis
  76. GRB080413A: Swift/UVOT observations
  77. GRB 080413B, Swift-BAT refined analysis
  78. GRB 080413A: Swift-XRT refined analysis
  79. GRB 080413A, Swift-BAT refined analysis
  80. GRB 080413A Bootes observation
  81. GRB 080413A: VLT/UVES redshift
  82. GRB 080413B: VLT redshift
  83. GRB080413B: REM NIR & Optical Observation
  84. GRB 080413B: GROND detection of afterglow in all bands
  85. GRB 080413B: Swift detection of a possibly short burst with optical counterpart
  86. GRB 080413A: REM detection of the NIR Afterglow
  87. GRB 080413: Enhanced Swift-XRT position
  88. GRB 080413: TAROT Calern observatory optical observations
  89. GRB 080413: Swift detection of a burst with an optical afterglow
  90. GRB 080413: ROTSE-III Detection of Optical Counterpart
  91. GRB 080411: Swift/UVOT refined analysis
  92. GRB 080411, Swift-BAT refined analysis
  93. GRB 080411: Swift-XRT Refined Analysis
  94. Konus-Wind observation of GRB 080411
  95. GRB 080411: Enhanced Swift-XRT position
  96. GRB 080411: VLT redshift
  97. GRB 080411: GROND detection of optical afterglow candidate
  98. GRB080330: MAGIC telescope GeV observation
  99. GRB 080411: Swift detection of a bright burst
  100. GRB 080330: Swift-XRT refined position retraction

Advanced

Download all Circulars as a .tar.gz archive:
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov