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"

26042 results found.

  1. Correction to Eiso calculation in GCN 3835 on GRB 050820A
  2. GRB050820A: Radio Observation
  3. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  4. GRB050820a BVRcIc field photometry
  5. GRB050820B XMM-Newton observation
  6. GRB 050820a: NIR Observations by WIRO
  7. GRB 050820B: Swift XRT position
  8. GRB050820B: Refined analysis of the Swift-BAT burst
  9. GRB050820B: BAT-Swift detection of a bright GRB
  10. Swift/UVOT photometry of GRB050820
  11. GRB050820: refined XRT analysis
  12. GRB 050820: Early RAPTOR detections
  13. GRB 050820 Swift-BAT refined analysis
  14. GRB 050820: P60 Temporal Decay Index
  15. GRB 050820: High Resolution Spectroscopy from Keck
  16. GRB050819: refined XRT analysis
  17. GRB 050820: Swift detection of a GRB
  18. GRB050820: Optical afterglow from P60
  19. GRB 050819 Swift-BAT refined analysis
  20. GRB050819: Swift XRT position
  21. GRB050819: Swift-BAT detection of a weak burst
  22. Swift-BAT trigger 150993 is not a GRB
  23. Swift Trigger 150823 is HETE J1900.1-2455
  24. GRB 050815: Radio Observation
  25. GRB050814: Radio Observation
  26. GRB050817: Swift-BAT Detection of a burst
  27. GRB 050814: continued fading
  28. GRB050815: Optical afterglow detection by Swift UVOT
  29. GRB050815: XRT refined analysis
  30. GRB 050813: Radio Observations
  31. GRB050815: Refined analysis of the Swift-BAT burst
  32. GRB 050815: ROTSE-III Optical Limits
  33. GRB050815: Swift XRT afterglow localization
  34. GRB050815: Swift-BAT detection of a burst
  35. GRB 050730: Third Epoch WSRT Radio Observations
  36. GRB050814: Fading red source
  37. GRB 050813: Gemini Spectra Revisited
  38. GRB050814: P60 Optical Afterglow Candidate
  39. GRB 050813: Non-fading of afterglow candidate
  40. GRB 050814: XRT refined analysis
  41. GRB050814: SWIFT/UVOT observation
  42. GRB050814: Refined analysis of the Swift-BAT burst
  43. GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
  44. GRB 050814: Swift XRT Afterglow Localization
  45. GRB 050814: Swift detection of a burst
  46. GRB 050813: Magellan detection of a high redshift galaxy cluster
  47. GRB 050813: I-band observations
  48. GRB050813, SDSS pre-burst observations
  49. GRB 050813: KAIT optical limit
  50. GRB 050813: Swift-BAT refined analysis
  51. GRB 050813: Photometry of object in XRT error circle
  52. GRB050813: SWIFT/UVOT observation
  53. GRB 050813: Swift XRT afterglow localization
  54. GRB 050813: Possible Short Swift-BAT GRB
  55. GRB050813 (Swift 150139): P60 Observations
  56. Swift-BAT trigger 150131 is not a GRB
  57. GRB050803: CrAO optical observations, no OT candidate
  58. GRB 050730: WSRT Radio Observations
  59. GRB 050803: PROMPT BVRcIc Observations
  60. GRB 050730, optical observation
  61. GRB050805b: CrAO optical limit
  62. GRB050805a : Null detection report
  63. GRB050803, optical observations
  64. Swift-BAT trigger 149118 is very likely not a GRB
  65. Retraction of Swift Trigger 149131 (GRB 050805B)
  66. GRB 050805b: OHP optical limits
  67. GRB 050805b: TAROT optical limits
  68. GRB050805b: MASTER optical observations
  69. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  70. GRB050805a: MASTER optical candidat
  71. Swift-BAT trigger 149118 is probably not a GRB
  72. GRB050802: TNG optical observations
  73. GRB 050803: RTT150 optical observations
  74. GRB050803: CrAO optical observations, possible OT candidate
  75. GRB050803: Optical/UV Upper Limits from Swift-UVOT
  76. GRB 050803: Keck Observations
  77. GRB 050803: Swift-BAT refined analysis
  78. GRB 050802.422: Fading of the afterglow and detection of the host
  79. GRB050803: MASTER further analys
  80. GRB 050803, optical observations
  81. GRB 050803: Magellan Observations
  82. GRB 050803: early Swift XRT analysis results
  83. GRB 050803: TAROT optical limits
  84. GRB050803: MASTER optical observations
  85. GRB050802: Tentative absorption redshift
  86. GRB050803: Swift-BAT detection of a very long burst
  87. GCN GRB observation 050713A
  88. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  89. GRB 050802: Swift/UVOT optical and UV detections
  90. GRB050801: Unchanged decay slope
  91. GRB050802 radio non-detection
  92. GRB 050730: OHP optical observations
  93. GRB 050802: early Swift XRT analysis results
  94. GRB 050802: Swift/UVOT observations
  95. GRB 050802: Swift-BAT refined analysis
  96. GRB050801: Optical photometry and decay index
  97. GRB 050802: XRT position
  98. GRB 050802: Swift Gamma-ray Burst
  99. GRB050801: Swift/UVOT Optical and UV detections
  100. GRB 050730: Preliminary Analysis of MIKE Spectrum

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