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"

37505 results found.

  1. GRB050820B at FRAM
  2. GRB050820A: RTT150 optical observations
  3. GRB 050820a - corrections to GCN 3846
  4. Swift/UVOT UV Photometry of GRB 050820B
  5. GRB 050822: ROTSE-III Prompt Optical Limits
  6. GRB 050822: Swift detection of a long burst
  7. Correction to Eiso calculation in GCN 3835 on GRB 050820A
  8. GRB050820A: Radio Observation
  9. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  10. GRB050820a BVRcIc field photometry
  11. GRB 050820a: NIR Observations by WIRO
  12. GRB 050820B: Swift XRT position
  13. GRB050820B: Refined analysis of the Swift-BAT burst
  14. GRB050820B: BAT-Swift detection of a bright GRB
  15. GRB050820: refined XRT analysis
  16. GRB 050820: Early RAPTOR detections
  17. GRB 050820 Swift-BAT refined analysis
  18. GRB 050820: P60 Temporal Decay Index
  19. GRB 050820: High Resolution Spectroscopy from Keck
  20. GRB050819: RTT150 optical observations
  21. GRB 050820: Swift detection of a GRB
  22. GRB 050819 Swift-BAT refined analysis
  23. GRB050819: Swift XRT position
  24. GRB050819: Swift-BAT detection of a weak burst
  25. Swift-BAT trigger 150993 is not a GRB
  26. Swift Trigger 150823 is HETE J1900.1-2455
  27. GRB 050817: Optical observations
  28. GRB 050815: Radio Observation
  29. GRB050814: Radio Observation
  30. GRB050817: Negative Optical Observations
  31. GRB 050814: continued fading
  32. GRB 050813: Radio Observations
  33. GRB050815: Refined analysis of the Swift-BAT burst
  34. GRB 050815: ROTSE-III Optical Limits
  35. GRB050815: Swift XRT afterglow localization
  36. GRB 050730: Third Epoch WSRT Radio Observations
  37. GRB050814: Fading red source
  38. GRB 050813: Gemini Spectra Revisited
  39. GRB 050813: Non-fading of afterglow candidate
  40. GRB 050814: XRT refined analysis
  41. GRB050814: Refined analysis of the Swift-BAT burst
  42. GRB050813: Gemini Imaging
  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. GRB050813: RTT150 optical observations
  48. GRB 050813: I-band observations
  49. GRB050813, SDSS pre-burst observations
  50. GRB 050813: KAIT optical limit
  51. GRB 050813: Swift-BAT refined analysis
  52. GRB 050813: Photometry of object in XRT error circle
  53. GRB 050813: Swift XRT afterglow localization
  54. RBO GRB 050714A and GRB 050716 observations
  55. GRB 050813: Possible Short Swift-BAT GRB
  56. Swift-BAT trigger 150131 is not a GRB
  57. GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
  58. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  59. GRB050803: CrAO optical observations, no OT candidate
  60. GRB 050730: WSRT Radio Observations
  61. GRB 050803: PROMPT BVRcIc Observations
  62. GRB 050807: ROTSE-III Optical Limits
  63. GRB 050730, optical observation
  64. GRB050805b: CrAO optical limit
  65. GRB050805a : Null detection report
  66. GRB050730, optical observations
  67. GRB050803, optical observations
  68. Swift-BAT trigger 149118 is very likely not a GRB
  69. Retraction of Swift Trigger 149131 (GRB 050805B)
  70. GRB 050805b: OHP optical limits
  71. GRB 050805b: TAROT optical limits
  72. GRB050805b: MASTER optical observations
  73. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  74. GRB050805a: MASTER optical candidat
  75. Swift-BAT trigger 149118 is probably not a GRB
  76. GRB 050803: RTT150 optical observations
  77. GRB050803: CrAO optical observations, possible OT candidate
  78. GRB 050803: Keck Observations
  79. GRB 050803: Swift-BAT refined analysis
  80. GRB 050802.422: Fading of the afterglow and detection of the host
  81. GRB050803: MASTER further analys
  82. GRB 050803, optical observations
  83. GRB 050803: Magellan Observations
  84. GRB 050803: early Swift XRT analysis results
  85. GRB 050803: TAROT optical limits
  86. GRB050803: MASTER optical observations
  87. GRB050802: Tentative absorption redshift
  88. GCN GRB observation 050713A
  89. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  90. GRB 050802: Swift/UVOT optical and UV detections
  91. GRB050802: CrAO optical observations
  92. GRB050801: Unchanged decay slope
  93. GRB 050730: OHP optical observations
  94. GRB 050802: early Swift XRT analysis results
  95. GRB 050802: Swift/UVOT observations
  96. GRB 050802 : Lulin Optical follow-up observation
  97. GRB 050802: Swift-BAT refined analysis
  98. GRB050801: Optical photometry and decay index
  99. GRB 050802: XRT position
  100. GRB 050802: Swift Gamma-ray Burst

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