Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! 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 100901A: optical observations in Mondy and R-light curve
  2. GRB100909A: NOT optical afterglow confirmation
  3. GRB 100909A: Swift-XRT refined analysis
  4. GRB 100906A: optical observations at Mt.Terskol
  5. GRB 100901A: optical observation in Maidanak, break confirmation
  6. GRB 100909A: Faulkes Telescope North afterglow candidate
  7. GRB 100909A: ROTSE-III Optical Limits
  8. GRB 100909A: Planned XMM-Newton observation
  9. GRB 100902A : Confirmation of afterglow and re-brightening with CFHT r’-band imaging
  10. GRB 100909A: Swift target of opportunity observation
  11. GRB 100909A: a long GRB detected by INTEGRAL
  12. GRB100906A: detection at 15GHz
  13. GRB100901A: IAO optical upper limits at 4 days after the burst
  14. EVLA detection of radio afterglow of GRB100901A
  15. GRB 100901A: Confirmation of WSRT Radio Detection
  16. GRB 100901A: CrAO optical observations
  17. GRB 100906A: RTT150 optical observations
  18. GRB 100906A: GRAS-007 optical observations
  19. GRB100906A: R band observations
  20. Konus-Wind observation of GRB 100906A
  21. GRB100906A: non-detection at 15GHz
  22. GRB100906A: Optical observations at IAO
  23. GRB 100906A: Fermi GBM observation
  24. GRB 100906A: TLS Monitoring
  25. GRB 100901A: TLS Detection at 5.5 days
  26. GRB 100906A: Observations at the Virtual Telescope
  27. GRB 100906A: Swift-XRT refined analysis
  28. GRB 100906A: Enhanced Swift-XRT position
  29. GRB 100906A: Swift/UVOT Observations
  30. GRB100906A: Errata of MITSuME Okayama about observation time
  31. GRB100906A: MITSuME Okayama Optical Observation
  32. GRB 100906A: Ondrejov 65cm observations
  33. GRB 100906A: TLS Multicolor Observations
  34. GRB 100905A: Swift/UVOT Upper Limits
  35. GRB 100901A: TLS observations, SDSS calibration, decay slope
  36. GRB 100906A: MASTER preliminary prompt+afterglow lc
  37. GRB 100901A: ISON-NM optical observations
  38. GRB 100906A: Swift-BAT refined analysis
  39. GRB 100906A: UKIRT zYJHK Observation
  40. GRB 100906A: MASTER preliminary polarization prompt light curve
  41. GRB 100906A: Gemini-N/GMOS redshift
  42. GRB 100906A : Faulkes Telescope North optical observations
  43. GRB 100906A: MASTER early OT observations
  44. GRB 100906A: Swift detection of a burst with an optical afterglow
  45. GRB 100829A: MASTER optical observations
  46. GRB100905A: Optical upper limits at IAO
  47. GRB100905A: MITSuME Okayama optical upper limits
  48. GRB 100905A: Swift-XRT refined analysis.
  49. GRB 100905A: UKIRT zJHK Observation
  50. GRB 100901A: Possible WSRT Radio Detection
  51. GRB100905A: 1.5m OSN upper limit
  52. GRB 100905A: Enhanced Swift-XRT position
  53. GRB 100905A: Swift-BAT refined analysis
  54. GRB100904A: BOOTES-3 Upper Limit
  55. GRB 100905A: MASTER Prompt Optical Observations
  56. GRB 100905A: Faulkes Telescope North observations
  57. GRB 100905A: Swift detection of a burst
  58. Optical observations of GRB 100901A
  59. GRB10901A: Murikabushi telescope observation at 3 days after the burst
  60. GRB 100901A: Submm observations from SMA
  61. GRB 100902A: UKIRT JK Observation
  62. GRB 100902A: GROND observations; afterglow candidate
  63. GRB 100901A: UKIRT zYJHK Observation
  64. GRB 100904A: Swift-BAT refined analysis
  65. GRB100902A: Optical upper limits at IAO
  66. GRB10901A: Optical observations at IAO
  67. Konus-Wind observation of GRB 100829A
  68. GRB 100904A: Swift detection of a burst
  69. GRB 100902A: Swift-BAT refined analysis
  70. GRB 100901A: optical observation at Mt.Terskol
  71. GRB 100901A: multicolor photometry at Mt.Terskol
  72. IPN Triangulation of the very bright GRB 100829A
  73. GRB 100901A: Lightbuckets Optical Observations
  74. GRB 100901A: HCT optical observations
  75. GRB 100902A: 1.5m OSN I-band Upper Limits
  76. Tentative redshift of GRB100902A from Swift-XRT data
  77. GRB 100902A: Swift XRT refined analysis
  78. GRB 100902A: Swift/UVOT Upper Limits
  79. GRB 100902A: optical observation at Mt.Terskol
  80. GRB 100901A: optical observation at Mt.Terskol
  81. GRB 100901A: Kanata Telescope observation of the optical afterglow
  82. GRB100901A: MITSuME Okayama Optical Observation at 1 day after the burst
  83. GRB 100902A: Enhanced Swift-XRT position
  84. GRB 100901A: TLS Observations: Break?
  85. GRB100901A: Errata of MITSuME Okayama about reference catalog
  86. GRB 100902A: MASTER Prompt Optical Observations
  87. GRB 100901A: ISON-NM optical observations
  88. GRB 100902A: Faulkes Telescope South observations
  89. GRB 100902A: MASTER Optical Early Limit
  90. GRB 100902A: Swift detection of a burst
  91. GRB 100901A: 1.5m OSN BVRI-band observations.
  92. GRB 100901A: ROTSE-III Detection
  93. GRB 100901A: MASTER optical flare at 420s discovery
  94. GRB 100901A: Vega telescope optical afterglow observation
  95. Swift/UVOT Observations of GRB100901A
  96. GRB 100901A : HCT optical observations
  97. GRB 100901A: SARA-N observations
  98. GRB 100901A: THO optical observations
  99. GRB100901A: MITSuME Okayama Optical Observation
  100. GRB 100901A: Swift-XRT Team refined analysis

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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