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 080212, Swift-BAT refined analysis
  2. GRB080212: Optical afterglow candidate observed by MITSuME Telescope
  3. GRB 080212: Gemini-South optical observations
  4. GRB 080212: GROND detects afterglow
  5. GRB 080212: REM NIR afterglow?
  6. GRB 080212: optical observations
  7. GRB 080212: Enhanced Swift-XRT position
  8. GRB 080212: Swift-XRT Team refined analysis
  9. GRB 080210: Keck photometry
  10. VLA non-detection of GRB 080210
  11. GRB 080212: Swift detection of a burst
  12. IPN localization of GRB 080211
  13. GRB 080212: DSS/2MASS Galaxy at XRT position
  14. GRB 080207: VLT NIR early upper limits
  15. GRB 080210: Swift/UVOT Refined Analysis
  16. GRB 080207: optical observations.
  17. GRB 080210: Hobby-Eberly Telescope Absorption Spectroscopy
  18. GRB 080210, Swift-BAT refined analysis
  19. GRB 080210: Super-LOTIS observations
  20. GRB 080210: Swift-XRT Refined Analysis
  21. GRB 080210: VLT redshift
  22. GRB 080210: Enhanced Swift-XRT position
  23. GRB 080210: Rapid PROMPT Detections
  24. GRB 080210: GOND detection in all bands and redshift upper limit
  25. GRB080210 - SDSS Pre-Burst Observations
  26. GRB 080210: Swift detection of a burst with optical afterglow
  27. GRB 080210: TAROT La Silla observatory optical detection
  28. GRB 080207: GROND upper limits
  29. GRB 080205: GAO 150cm telescope Optical limit
  30. GRB 080207, Swift-BAT refined analysis
  31. GRB 080207: Optical limits from Gemini-South
  32. GRB 080205: RTT150 optical observations
  33. Swift detection of AX J1749.1-2639
  34. GRB 080207: Super-LOTIS observations
  35. GRB 080207, Swift-BAT refined analysis
  36. Swift Trigger 302777 is not a GRB
  37. GRB080207: RTT150 Optical Observations
  38. GRB 080207: REM NIR observations
  39. GRB080207: Swift/UVOT refined analysis
  40. GRB 080207: TAROT Calern observatory optical observations
  41. GRB 080207: Swift-XRT Refined Analysis
  42. GRB 080207: Enhanced Swift-XRT position
  43. GRB 080207: Swift detection of a burst
  44. Konus-Wind observation of GRB 080204
  45. GRB 080205 optical upper limit
  46. GRB 080205: MASTER optical observation
  47. GRB 080205: optical observation
  48. VLA radio upper limit on GRB 080205
  49. INT+WFC R-band observations of GRB 080205
  50. GRB 080205, Swift-BAT refined analysis
  51. IPN localization of very hard GRB 080204
  52. GRB 080205: Swift XRT refined analysis
  53. GRB 080205: OA evolution from KAIT observations
  54. GRB 080205: Swift/UVOT observations
  55. GRB 080205: Enhanced Swift-XRT position
  56. GRB 080205: KAIT OA detection
  57. GRB 080205: Swift detection of a burst
  58. Swift-BAT Trigger #302454, correction of GCN notice, update on AX J1749.1-2639
  59. GRB 080130: Swift-BAT refined analysis
  60. GRB 080130: further Swift XRT observations confirm fading source
  61. GRB 080129: Swift/UVOT Refined Upper Limits
  62. Swift/UVOT observations of GRB080130
  63. GRB 080130: REM NIR observations
  64. GRB 080130(?): Swift XRT observation
  65. GRB 080130?: Detection of a possible burst by BATSS
  66. GRB 080129: Optical observations from OSN
  67. GRB 080129: Swift-XRT refined analysis
  68. X-ray transient in NGC 2770: RTT150 optical observations
  69. GRB 080129: KAIT optical limits
  70. GRB 080123: Early afterglow detection with BATSS (BAT Slew Survey)
  71. GRB 080129: optical limit by Pi of the Sky
  72. GRB 080129, Swift-BAT refined analysis
  73. GRB 080129: TAROT La Silla observatory optical observations
  74. GRB 080129: Gemini-South photometry
  75. GRB 080129: GROND detection in all bands, and fading
  76. GRB 080129: GROND detection of the optical/NIR afterglow, and fading
  77. GRB 080129: Enhanced Swift-XRT position
  78. GRB 080129: Gemini-South Imaging Observations
  79. GRB 080129: Swift XRT position
  80. GRB 080129 (?): UVOT Upper Limits
  81. GRB 080129 (?): Swift detection of a possible burst
  82. A new website of high-level data products for Swift GRBs
  83. GRB 080121: Upper limit on X-ray afterglow
  84. GRB 080123 : Suzaku WAM observation of the prompt emission
  85. Swift trigger(=301779) is not a GRB
  86. Transient 080109/SN 2008D: Spectroscopic Evolution
  87. GRB 080122: pseudo-z= 1.93 from prompt emission spectrum
  88. Konus-Wind observation of GRB 080122
  89. GRB 080122 : Suzaku WAM observation of the prompt emission
  90. GRB 080121: Swift/UVOT upper limits
  91. SNe 2008D and 2007uy: Chandra Detections
  92. GRB 080121 position was incorrect
  93. GRB 080121: Enhanced Swift-XRT position
  94. Two non-burst Swift SubThreshold triggers
  95. Transient 080109/SN 2008D: Spectroscopic Evolution and Re-Classification
  96. IPN triangulation of GRB080122
  97. GRB 080121: Nearby SDSS galaxies
  98. GRB 080121: Swift-BAT detection of a very weak, short burst
  99. GRB 080123: Swift-XRT refined analysis
  100. GRB 080123: Swift/UVOT 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