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. GRB060210: Optical Observations
  2. GRB060210: Gemini absorption spectroscopy
  3. GRB060210: Early Optical Observations
  4. GRB 060210: optical evolution
  5. GRB060210:Faulkes Telescope North Afterglow Confirmation
  6. GRB 060210: candidate afterglow
  7. GRB 060210: Swift detection of a burst
  8. GRB060210: Optical afterglow
  9. GRB 060206: Swift/UVOT Observations
  10. Swift-BAT trigger 180931 is not a GRB
  11. GRB060209: RTT150 optical observations
  12. GRB 060209 : TAROT optical observation
  13. GRB060209A: MASTER optical observation
  14. GRB 060209(?): Swift-BAT detection of a possible burst
  15. GRB 060206: near-infrared observations (JK' imaging)
  16. GRB 060206: WSRT Radio Observations
  17. GRB 060203: Swift/UVOT upper limits
  18. GRB 060206: TTT Observations
  19. GRB 060206: More PROMPT Detections
  20. GRB 060121 : WIDGET Pre-trigger limit
  21. GRB 060206: Tenagra II Observations
  22. GRB 060206: PROMPT Detections
  23. Retraction of orphan GRB afterglow candidate
  24. GRB060204a: Swift XRT Source is not GRB Afterglow
  25. GRB 060206: optical observations at Asiago
  26. Orphan GRB Afterglow candidate
  27. GRB 060204b: pseudo-z from spectral parameters of the prompt emission
  28. GRB 060206: Subaru/FOCAS optical spectroscopy
  29. GRB 060206: IR Detection of the Afterglow
  30. GRB 060206: Lick 3m Spectroscopy
  31. GRB 060204A: ROSAT Pointing
  32. GRB 060206: Super-LOTIS observations
  33. GRB060204A: Swift/UVOT observations
  34. GRB 060206: Swift-BAT refined analysis
  35. GRB 060206 : Lulin optical observations
  36. GRB060206: SDSS Pre-Burst Observations
  37. GRB060206: Swift XRT Refined Analysis
  38. GRB060206: Liverpool Telescope observation
  39. GRB 060206: Spectroscopic Redshift
  40. GRB060206: P60 Optical Observations
  41. GRB 060206: KAIT observations
  42. GRB060206: Swift XRT Position
  43. GRB060206: SARA Detection
  44. GRB 060206: RAPTOR observations of afterglow candidate variability.
  45. GRB 060206: High redshift burst
  46. GRB060204a: Swift XRT Detection of an Afterglow Candidate
  47. GRB060206 - Swift UVOT Confirmation of Optical Afterglow
  48. GRB060206: Optical afterglow
  49. GRB060206: Swift-BAT detection of a burst
  50. GRB 060204C: XRT analysis of Swift J061223.0+701243.9
  51. GRB060203: WHT Z-band observations
  52. BAT GRB 060204C is probably not a GRB
  53. GRB060204C: optical observation
  54. GRB 060204B: BVRi-band detections of optical afterglow
  55. GRB 060204A: Swift XRT upper limit
  56. GRB 060204A: FRAM optical observations
  57. GRB060204B: Swift/UVOT refined analysis
  58. GRB 060204C: optical observations
  59. Swift XRT Observation of GRB 060204C
  60. GRB 060204B: Swift-BAT refined analysis
  61. GRB 060204B: ART early limit
  62. GRB060204B: Swift XRT Team Refined Analysis
  63. GRB 060204C: OSN limits
  64. GRB 060204b: Keck/LRIS Afterglow Confirmation
  65. GRB 060204C: BOOTES-IR optical limits
  66. GRB 060204C: Liverpool Telescopes optical limit
  67. GRB 060204C: ROTSE-III Optical Limits
  68. GRB 060204C: Swift-BAT detection of a burst
  69. GRB 060124: Radio Observations
  70. GRB060204B: Faulkes OT candidate
  71. GRB 060204B: ART optical limit
  72. GRB 060204A: further INTEGRAL results
  73. GRB060204B, optical observation
  74. GRB060204B - SDSS pre-burst observations
  75. GRB 060203: Swift-BAT refined analysis
  76. GRB 060204B: Swift detection of a burst
  77. GRB 060204: a long GRB detected by INTEGRAL
  78. GRB 060202: UKIRT/WFCAM K-band and KeckI/LRIS I-band Observation
  79. GRB 060203: RTT150 optical observations
  80. GRB060203: Swift XRT Team Refined Analysis
  81. GRB060203 - Swift UVOT observation
  82. Swift-BAT trigger is GRB 060203
  83. GRB 060203: IR Counterpart
  84. GRB060203: Observations with SARA
  85. GRB 060203: P60 Confirmation of Optical Afterglow
  86. Possible GRB 060203: candidate optical counterpart
  87. Swift BAT Trigger 180151: Swift XRT source detection
  88. Possible GRB 060203: optical observations at Asiago
  89. GRB 060202: PROMPT Observations
  90. Swift-BAT trigger 180151 is unknown origin at this time
  91. GRB 060202: GETS observation
  92. GRB 060202: Gemini-N J, H, K_s observations
  93. GRB 060202 : Kiso B and R band limit
  94. GRB 060202: Near-IR Observation with UKIRT/WFCAM
  95. GRB 060202: Optical Afterglow Candidate from Keck/LRIS
  96. GRB 060202: Refined analysis of the Swift-BAT burst
  97. GRB060202, optical observation
  98. GRB 060202: Swift/UVOT upper limits
  99. GRB 060202: Swift XRT Team Refined Analysis
  100. GRB 060202 : Lulin R and I band 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