Skip to main content
Retirement of GCN Classic VOEvent Brokers. 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 080607: Enhanced Swift-XRT position
  2. GRB 080607, Swift-BAT refined analysis
  3. GRB 080605: GROND 2nd epoch observations
  4. GRB 080607 - PAIRITEL NIR detection
  5. GRB 080607: Keck/LRIS spectroscopy and redshift
  6. GRB 080607: Super-LOTIS early observations
  7. GRB 080607: Swift detection of a burst with optical afterglow
  8. GRB 080607: ROTSE-III Detection of Optical Counterpart
  9. GRB 080605: TLS RRM Analysis, Plateau/Rebrightening, Red OT
  10. GRB 080605: Swift-UVOT refined analysis
  11. Possible VLA radio detection on INTEGRAL burst GRB 080603A
  12. GRB 080604: VLA radio upper limit
  13. GRB 080605, Swift-BAT refined analysis
  14. GRB 080603B: VLA radio upper limit
  15. GRB 080605, Swift-BAT refined analysis
  16. GRB 080605: Swift-XRT refined analysis
  17. GRB080605: observation by BOOTES
  18. GRB 080605: MASTER VWF 46 s AT observation
  19. GRB 080605: Enhanced Swift-XRT position
  20. GRB 080605: GROND detection of the optical afterglow candidate
  21. GRB080605: optical observations
  22. GRB 080605: VLT redshift
  23. GRB 080605: Liverpool Telescope optical afterglow candidate
  24. GRB 080605: Swift/UVOT Position of the Optical Afterglow
  25. GRB 080605: TLS RRM Afterglow
  26. GRB 080605: Swift detection of a burst with an optical afterglow
  27. GRB 080603B: PAIRITEL infrared detection
  28. GRB 080603A: PAIRITEL infrared detection
  29. GRB 080604: Xinglong R band observation
  30. GRB 080603A: Xinglong R band observation
  31. GRB 080603B: TLS Afterglow Observation
  32. GRB 080603A: TLS Afterglow Observation
  33. GRB 080604: MITSuME Okayama observation
  34. Swift/UVOT observations of GRB080604
  35. GRB080604: HET redshift retraction
  36. GRB 080604: Gemini-North spectroscopy
  37. GRB 080604, Swift-BAT refined analysis
  38. GRB 080604: Swift-XRT refined analysis
  39. GRB 080603B: Hobby-Eberly Telescope redshift confirmation
  40. GRB 080603B : Xinglong EST observations
  41. GRB 080603B : Liverpool Telescope Observations
  42. Konus-Wind observation of GRB 080603B
  43. GRB 080603B: Swift-XRT refined analysis
  44. GRB 080603A: Swift-XRT detection of the afterglow
  45. GRB 080430: optical observations
  46. GRB 080603B: Swift/UVOT detection of the afterglow
  47. GRB 080604: Enhanced Swift-XRT position
  48. GRB 080603B, Swift-BAT refined analysis
  49. GRB 080604: Hobby-Eberly Telescope spectroscopy
  50. GRB 080603A: Swift/UVOT detection of the afterglow
  51. GRB080603B: RTT150 optical observations, break in light curves
  52. GRB 080604: Early Super-LOTIS Observations
  53. GRB080604: confirmation of optical afterglow
  54. GRB 080604: Swift detection of a burst with an optical afterglow
  55. GRB 080603B: TAROT Calern observatory confirmation of slow optical decay
  56. GRB 080516: TAROT La Silla observatory optical observations
  57. GRB080603B: NOT redshift
  58. GRB 080603B: BOOTES2/TELMA optical observations
  59. GRB 080603B: TAROT Calern observatory detection of a plateau in the light curve
  60. GRB 080603B: Swift detection of a burst with optical afterglow
  61. GRB080603: Super-LOTIS detection of Optical Counterpart
  62. GRB 080603B: ROTSE-III Detection of Optical Counterpart
  63. GRB 080603: Gemini-North redshift
  64. GRB 080603: A long GRB detected by INTEGRAL
  65. GRB 080603 OA candidate
  66. Possible GRB080603: Faulkes Telescope North optical afterglow candidate
  67. SGR 1627-41: Chandra/RXTE/Swift Observations Scheduled
  68. GRB 080602, Swift-BAT refined analysis
  69. GRB 080602: Swift-XRT refined analysis
  70. Konus-Wind observation of GRB 080602
  71. GRB 080602: NOT R-band upper limit
  72. GRB 080602: Enhanced Swift-XRT position
  73. GRB 080602: Swift detection of a burst
  74. Swift analysis of BAT Slew Survey event (Trigger=009)
  75. GRB 080523: afterglow confirmation and redshift constraints
  76. Konus-Wind observation of reactivation of SGR 1627-41
  77. Reactivation of SGR 1627-41
  78. GRB 080524: Swift XRT and UVOT analysis
  79. GRB 080503: 2nd Epoch Chandra X-ray Observations
  80. GRB 080524: Swift-BAT detection of a burst in ground analysis
  81. GRB 080523: Swift-XRT refined analysis
  82. GRB 080523, Swift-BAT refined analysis
  83. GRB 080520: VLT host detection
  84. GRB 080523: VLT optical observations
  85. Swift/UVOT observations of GRB 080523
  86. GRB 080523: Enhanced Swift-XRT position
  87. GRB 080523: Swift detection of a burst
  88. GRB 080515: NIR magnitude correction
  89. GRB 080515: KPNO 4m NIR afterglow detection
  90. GRB080521(?): detection of possible burst from BAT slew data and XRT ToO
  91. GRB 80516: Swift/UVOT Observations
  92. GRB 080515: Swift-XRT position and analysis
  93. GRB 080520, Swift-BAT refined analysis
  94. GRB 080514B: pseudo-z= 1.8 from prompt emission spectrum
  95. GRB 080514B: UVOT Observations
  96. GRB080520: Swift/UVOT observations
  97. GRB 080520: VLT redshift
  98. GRB 080520, GROND observations
  99. GRB 080520: Enhanced Swift-XRT position
  100. GRB 080520: Swift XRT Refined Analysis

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