Skip to main content
New! BOOM Notices and Schema v7.0.0. 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"
  1. GRB 100526A: Gemini/NIRI infrared afterglow candidate
  2. GRB 100526A: NOT optical upper limit
  3. GRB 100526A: Swift XRT refined analysis
  4. GRB 100526B: Swift-BAT refined analysis
  5. GRB 100526B: Swift XRT/UVOT observations
  6. GRB 100526A: Swift-BAT refined analysis
  7. GRB 100526A: Enhanced Swift-XRT position
  8. GRB 100526B: Swift detection of a probable GRB
  9. GRB 100526A: MASTER-Net optical alert observations
  10. GRB 100526A: Swift detection of a burst
  11. Konus-Wind observation of GRB 100522A
  12. GRB100522A: Suzaku WAM observation of the prompt emission
  13. GRB 100418A: Subaru late-time optical imaging and spectroscopy
  14. GRB 100522A: GROND observations, upper limits
  15. Swift/UVOT observations of GRB100522A.
  16. GRB 100522A: Fermi GBM observation
  17. GRB 100522A: Swift XRT refined analysis
  18. GRB 100522A, Swift-BAT refined analysis
  19. GRB 100522A: Enhanced Swift-XRT position
  20. GRB 100522A: NIR observations from CAHA
  21. GRB 100522A: BOOTES-2 optical limit
  22. GRB 100522A: Swift detection of a burst
  23. GRB 100418A: CrAO optical observations
  24. GRB 100518A: GROND afterglow observation and photo-z
  25. GRB 100518A: Swift/UVOT Upper Limits
  26. GRB 100518A: Swift-XRT refined analysis
  27. GRB 100518A: optical afterglow decay
  28. GRB 100518A: BOOTES-3 optical observations
  29. Update to the configuration of the Fermi-LAT onboard GRB search
  30. GRB 100518A: Faulkes Telescope North Afterglow Candidate
  31. GRB 100518A: Swift target of opportunity observation of the INTEGRAL burst
  32. GRB 100513A: MITSuME Akeno Optical Observation
  33. Swift-BAT trigger 422437 is not anything astrophysical
  34. GRB 100518A: a long GRB detected with INTEGRAL
  35. Swift Trigger 422437 is probably not a GRB
  36. Fermi/GBM trigger 295791986 - unreliable location
  37. GRB 100517A: MASTER-Net wide field camera prompt optical observations
  38. GRB 100513A: EVLA radio observation
  39. GRB 100514A: optical afterglow confirmation
  40. GRB 100514A: Swift/UVOT Observations
  41. GRB 100514A: YNAO-GMG observations
  42. GRB 100514A: Swift XRT refined analysis
  43. GRB 100514A: MASTER-Net optical observations
  44. GRB 100514A: Enhanced Swift-XRT position
  45. GRB 100514A: Swift-BAT refined analysis
  46. GRB 100514A: Faulkes Telescope South observations
  47. GRB 100514A: Swift detection of a burst
  48. GRB 100513A: Faulkes Telescope South observations
  49. GRB 100513A: Swift/UVOT upper limits
  50. GRB 100513A, RIMOTS optical upper limits
  51. GRB 100513A: Swift XRT refined analysis
  52. GRB 100513A: Swift-BAT refined analysis
  53. GRB 100513A: Gemini/GMOS Spectroscopic Redshift
  54. GRB 100513A: Enhanced Swift-XRT position
  55. GRB 100513A: Lick observations and R-band dropout
  56. GRB 100513A: PAIRITEL continued observations and confirmation of fading
  57. GRB 100513A: SARA-N Upper Limit
  58. GRB 100513A: PAIRITEL NIR afterglow candidate
  59. GRB 100513A: Swift detection of a burst
  60. GRB 100510A: Fermi GBM detection/observation
  61. GRB 100511A: Fermi GBM detection/observation
  62. GRB 100511A: Super-LOTIS early observations
  63. Swift-BAT trigger 421695 is likely not astrophysical
  64. GRB100504A: Optical upper limits at IAO
  65. GRB 100510A: MAXI/GSC detection
  66. GRB 100511A, RIMOTS optical upper limits
  67. Trigger 421695: Swift detection of a possible burst
  68. GRB100508A: Further Swift/UVOT Observations
  69. GRB100503A: Suzaku WAM observation of the prompt emission
  70. GRB 100508A: GROND Detection of the optical afterglow
  71. GRB 100508A: Swift-XRT Refined analysis
  72. GRB 100508A: Swift-BAT refined analysis
  73. GRB 100508A: Enhanced Swift-XRT position
  74. GRB100508A: Swift/UVOT Detection of the Afterglow
  75. GRB 100508A: ROTSE-III Optical Limits
  76. GRB 100508A: Swift detection of a burst
  77. GRB 100418A: Keck imaging
  78. GRB 100418A: RTT150 optical observations
  79. Fermi Gamma-ray Burst Monitor trigger 294712621 is not a GRB
  80. Swift-BAT refined analysis of trigger 421262
  81. GRB 100504A: Fermi GBM observation
  82. An SGR-like burst from the magnetar 1E 1841-04.5 in Kes 73
  83. GRB 100504A: Swift/UVOT Observations
  84. GRB 100418A: Flattening of the Swift/UVOT Optical Light Curve
  85. GRB 100504A: Swift-XRT refined analysis
  86. GRB 100504A: Enhanced Swift-XRT position
  87. GRB 100504A: GROND Upper limits
  88. GRB 100504A: Swift-BAT refined analysis
  89. GRB 100504A: SARA-South Upper Limit
  90. GRB 100503A: Fermi GBM detection
  91. GRB 100504A: UVOT-enhanced XRT position
  92. GRB 100504A: Swift detection of a burst
  93. Swift-BAT trigger 421072 is not astrophyical
  94. INTEGRAL observations of Swift GRB trigger 421072
  95. GRB100423A : Suzaku WAM observation of the prompt emission
  96. Trigger 421072: Possible Swift detection of a GRB or transient
  97. GRB 100420A: EVLA radio observations
  98. GRB 100420A: Gemini discovery of infrared afterglow
  99. GRB 100423A: xinglong TNT optical upper limit
  100. GRB 100420A: Terskol optical upper limit

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