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"

45645 results found.

  1. GRB 050820a - corrections to GCN 3846
  2. Swift/UVOT UV Photometry of GRB 050820B
  3. GRB 050822: ROTSE-III Prompt Optical Limits
  4. GRB 050822: Swift detection of a long burst
  5. Correction to Eiso calculation in GCN 3835 on GRB 050820A
  6. GRB050820A: Radio Observation
  7. GRB050825a - very long GRB like GRB041219a? (Konus-Wind observation)
  8. GRB050820a BVRcIc field photometry
  9. GRB050820B XMM-Newton observation
  10. GRB 050820a: NIR Observations by WIRO
  11. GRB 050820B: Swift XRT position
  12. GRB050820B: Planned XMM-Newton observation
  13. GRB050820B: Refined analysis of the Swift-BAT burst
  14. GRB050820B: BAT-Swift detection of a bright GRB
  15. Swift/UVOT photometry of GRB050820
  16. GRB050820: refined XRT analysis
  17. GRB 050820: Early RAPTOR detections
  18. GRB 050820 Swift-BAT refined analysis
  19. GRB 050820: P60 Temporal Decay Index
  20. GRB 050820: High Resolution Spectroscopy from Keck
  21. GRB050819: refined XRT analysis
  22. GRB050819: RTT150 optical observations
  23. GRB 050820: Swift detection of a GRB
  24. GRB050820: Optical afterglow from P60
  25. GRB 050819 Swift-BAT refined analysis
  26. GRB050819: Swift XRT position
  27. GRB050819: Swift-BAT detection of a weak burst
  28. Swift-BAT trigger 150993 is not a GRB
  29. Swift Trigger 150823 is HETE J1900.1-2455
  30. GRB 050817: Optical observations
  31. GRB 050815: Radio Observation
  32. GRB050814: Radio Observation
  33. GRB050817: Negative Optical Observations
  34. GRB050817: Swift-BAT Detection of a burst
  35. GRB 050814: continued fading
  36. GRB050815: Optical afterglow detection by Swift UVOT
  37. GRB050815: XRT refined analysis
  38. GRB 050813: Radio Observations
  39. GRB050815: Refined analysis of the Swift-BAT burst
  40. GRB 050815: ROTSE-III Optical Limits
  41. GRB050815: Swift XRT afterglow localization
  42. GRB050815: Swift-BAT detection of a burst
  43. GRB 050730: Third Epoch WSRT Radio Observations
  44. GRB050814: Fading red source
  45. GRB 050813: Gemini Spectra Revisited
  46. GRB050814: P60 Optical Afterglow Candidate
  47. GRB 050813: Non-fading of afterglow candidate
  48. GRB 050814: XRT refined analysis
  49. GRB050814: SWIFT/UVOT observation
  50. GRB050814: Refined analysis of the Swift-BAT burst
  51. GRB050813: Gemini Imaging
  52. GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
  53. GRB 050814: Swift XRT Afterglow Localization
  54. GRB 050814: Swift detection of a burst
  55. GRB 050813: Magellan detection of a high redshift galaxy cluster
  56. GRB050813: RTT150 optical observations
  57. GRB 050813: I-band observations
  58. GRB050813, SDSS pre-burst observations
  59. GRB 050813: KAIT optical limit
  60. GRB 050813: Swift-BAT refined analysis
  61. GRB 050813: Photometry of object in XRT error circle
  62. GRB050813: SWIFT/UVOT observation
  63. GRB 050813: Swift XRT afterglow localization
  64. RBO GRB 050714A and GRB 050716 observations
  65. GRB 050813: Possible Short Swift-BAT GRB
  66. GRB050813 (Swift 150139): P60 Observations
  67. Swift-BAT trigger 150131 is not a GRB
  68. GRB050807(=H3889): An X-Ray Rich GRB Localized by HETE
  69. Ongoing activity of SGR 1806-20: an intermediate burst 050811
  70. GRB050803: CrAO optical observations, no OT candidate
  71. Detection of an intermediate burst from SGR 1806-20 on August 8
  72. GRB 050730: WSRT Radio Observations
  73. GRB 050803: PROMPT BVRcIc Observations
  74. GRB 050807: ROTSE-III Optical Limits
  75. GRB 050730, optical observation
  76. GRB050805b: CrAO optical limit
  77. GRB050805a : Null detection report
  78. GRB050730, optical observations
  79. GRB050803, optical observations
  80. Swift-BAT trigger 149118 is very likely not a GRB
  81. Retraction of Swift Trigger 149131 (GRB 050805B)
  82. GRB 050805b: OHP optical limits
  83. GRB 050805b: TAROT optical limits
  84. GRB050805b: MASTER optical observations
  85. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  86. GRB050805a: MASTER optical candidat
  87. Swift-BAT trigger 149118 is probably not a GRB
  88. GRB050802: TNG optical observations
  89. GRB050803: Radio Observation
  90. GRB 050803: RTT150 optical observations
  91. GRB050801: Radio Observation
  92. GRB050730: Radio Detection
  93. GRB050803: CrAO optical observations, possible OT candidate
  94. GRB050803: Optical/UV Upper Limits from Swift-UVOT
  95. GRB 050803: Keck Observations
  96. GRB 050803: Swift-BAT refined analysis
  97. GRB 050802.422: Fading of the afterglow and detection of the host
  98. GRB050803: MASTER further analys
  99. GRB 050803, optical observations
  100. GRB 050803: Magellan Observations

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