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"

15984 results found.

  1. GRB 091208B, RIMOTS optical upper limits
  2. GRB 091208B: Swift detection of a burst with an optical afterglow
  3. GRB 091208B: BOOTES-3 optical afterglow
  4. GRB 091208: ROTSE-III Optical Limits
  5. Short X-ray Transient, RIMOTS optical upper limits
  6. GRB 091127: GAO 150cm telescope Optical Observation
  7. GRB 091202: GTC & CAHA optical/nIR afterglow candidate
  8. GRB 091109A: GROND confirmation of redshift z = 3.5
  9. GRB091127: Continuing Swift/UVOT Observations
  10. GRB 091127, SMARTS optical/IR afterglow observations
  11. GRB 091202: Optical and NIR observations
  12. GRB 091127: Zadko Telescope Observations
  13. GRB 091202: TAROT Calern observatory optical observations
  14. GRB 091117: Chandra Observations
  15. GRB 091020: MASTER-Net optical polarization observations
  16. GRB 091130A: Xinglong TNT upper limit
  17. GRB 091127: Radio observations
  18. GRB 091127: TAROT La Silla observatory optical observations
  19. GRB 091127: optical observations
  20. GRB 091127: LABOCA/APEX submm observations
  21. GRB 091127: Further NOT optical observations
  22. GRB 091127: MASTER early optical transient polarimetry
  23. GRB 091127: Swift-XRT afterglow detection and analysis
  24. GRB 091127: TAROT La Silla observatory optical decay
  25. GRB 091127: Swift/UVOT observations
  26. GRB 091127: CAHA 1.23m I-band observations
  27. GRB 091127: NOT observations
  28. GRB 091127: REM NIR afterglow detection
  29. GRB 091127: Swift/UVOT Detection of an Optical Afterglow
  30. GRB 091117: TNG optical observations
  31. GRB 091117: 2nd epoch of Magellan optical observations
  32. GRB 091117: Magellan optical observations
  33. GRB 091117: XRT source coincident with a DSS galaxy
  34. GRB 091109A: GROND and VLT observations
  35. GRB 091109b: Magellan Observations
  36. GRB 091109B: Optical limits from Watcher
  37. GRB 091109B: ROTSE-III Optical Limits
  38. GRB 091109: Swift/UVOT observations
  39. GRB 091109: Faulkes Telescope South observations
  40. GRB 091109: Swift detection of a burst with optical afterglow
  41. GRB 091104: Swift/UVOT Upper Limits
  42. GRB091102 : MOA optical upper limit
  43. GRB 091102: ROTSE-III Optical Limits
  44. GRB 091024: optical observations
  45. GRB 090926a, SMARTS optical/IR afterglow observations
  46. GRB 091029, SMARTS optical/IR afterglow observations
  47. GRB 091018, SMARTS optical/IR afterglow observations
  48. GRB091029: Swift/UVOT observations
  49. GRB091024 optical observations
  50. GRB 091029: Gemini-South Redshift
  51. GRB 091029: GROND Detection of the Optical/NIR Afterglow
  52. GRB 091029: Swift detection of a burst with an optical counterpart
  53. GRB 091024: Keck/LRIS Spectroscopy
  54. GRB 091024: YNAO-GMG observations
  55. GRB 091026: Swift/UVOT Upper Limits
  56. Konus-Wind and Konus-RF observations of GRB 091024
  57. GRB 091020 : Xinglong TNT upper limit
  58. GRB091024 Swift/UVOT Upper Limits
  59. GRB 091024: KAIT optical afterglow observations
  60. GRB 091024: Swift-XRT team refined analysis
  61. GRB 091024: Xinglong TNT optical observation
  62. GRB 091024: GRAS004 optical observations
  63. GRB091020 Swift/UVOT observations
  64. GRB 091020: NOT spectroscopic redshift
  65. GRB 091020: MASTER optical transient polarimetry
  66. GRB 090926A: Late-time Gemini South Observations and Possible Jet Break
  67. GRB 091020: Swift detection of a burst with an optical afterglow
  68. GRB 091018: ROTSE-III Detection of Optical Counterpart
  69. GRB 091018: Swift detection of a burst with optical afterglow
  70. GRB 091003: Possible Supernova Component
  71. GRB 091010: optical obsevation
  72. GRB 091015: RTT150 optical observations
  73. GRB 091010: optical afterglow candidate rejection
  74. GRB 091010: Enhanced XRT position
  75. GRB 091010 optical upper limits
  76. GRB 091010: Swift/UVOT Upper Limits
  77. GRB 090904A: afterglow confirmation
  78. GRB 091003: Swift/UVOT Detection of an Optical Afterglow
  79. GRB 090929B: Swift/UVOT Observations
  80. GRB 090929B: RAPTOR Discovery of Optical Counterpart
  81. GRB 090927: Faulkes Telescope South Detection of the Optical Afterglow
  82. GRB 090927: VLT redshift
  83. GRB 090927: Zadko Telescope observations
  84. Swift/UVOT observations of GRB 090927
  85. GRB090926A: Swift/UVOT observations
  86. GRB 090926B: VLT spectroscopy
  87. GRB 090927: Swift/UVOT detection of an optical afterglow
  88. GRB 090926B: optical object in error circle
  89. GRB 090926B: NOT optical observation
  90. GRB 090926A: Swift/UVOT detection of an optical afterglow
  91. GRB 090926A: Skynet/PROMPT Discovery of the Optical Afterglow
  92. GRB 090912: optical observation
  93. GRB 090915: Swift/UVOT detection of an optical afterglow candidate
  94. GRB 090912: Swift/UVOT Upper Limits
  95. GRB 090912 optical upper limit
  96. GRB 090904B: GROND detection of the optical afterglow
  97. GRB 090904B: MOA-II Optical observation
  98. GRB 090904A: NOT observations
  99. GRB 090902B: WSRT Radio Observation
  100. GRB 090904A: ROTSE-III Optical Limits

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