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"

28053 results found.

  1. XRF050509c: Radio upper limits from GMRT
  2. VLT/UVES spectroscopy of GRB050820
  3. GRB050822: Swift/UVOT upper limits
  4. GRB 050822: Swift-BAT refined analysis
  5. GRB050820A: RTT150 optical observations
  6. Swift/UVOT UV Photometry of GRB 050820B
  7. GRB 050822: ROTSE-III Prompt Optical Limits
  8. GRB 050822: Swift detection of a long burst
  9. GRB050820A: Radio Observation
  10. GRB050820a BVRcIc field photometry
  11. GRB050820B XMM-Newton observation
  12. GRB 050820a: NIR Observations by WIRO
  13. GRB 050820B: Swift XRT position
  14. GRB050820B: BAT-Swift detection of a bright GRB
  15. Swift/UVOT photometry of GRB050820
  16. GRB050820: refined XRT analysis
  17. GRB 050820: P60 Temporal Decay Index
  18. GRB 050820: High Resolution Spectroscopy from Keck
  19. GRB050819: refined XRT analysis
  20. GRB 050820: Swift detection of a GRB
  21. GRB050820: Optical afterglow from P60
  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. GRB 050815: Radio Observation
  27. GRB050814: Radio Observation
  28. GRB050817: Swift-BAT Detection of a burst
  29. GRB 050814: continued fading
  30. GRB050815: Optical afterglow detection by Swift UVOT
  31. GRB050815: XRT refined analysis
  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. GRB050815: Swift-BAT detection of a burst
  37. GRB 050730: Third Epoch WSRT Radio Observations
  38. GRB050814: Fading red source
  39. GRB 050813: Gemini Spectra Revisited
  40. GRB050814: P60 Optical Afterglow Candidate
  41. GRB 050813: Non-fading of afterglow candidate
  42. GRB 050814: XRT refined analysis
  43. GRB050814: SWIFT/UVOT observation
  44. GRB 050813: Gemini spectroscopy and redshifts of galaxies B and C
  45. GRB 050814: Swift XRT Afterglow Localization
  46. GRB 050814: Swift detection of a burst
  47. GRB 050813: Magellan detection of a high redshift galaxy cluster
  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. GRB050813: SWIFT/UVOT observation
  54. GRB 050813: Swift XRT afterglow localization
  55. GRB 050813: Possible Short Swift-BAT GRB
  56. Swift-BAT trigger 150131 is not a GRB
  57. GRB050803: CrAO optical observations, no OT candidate
  58. Detection of an intermediate burst from SGR 1806-20 on August 8
  59. GRB 050730: WSRT Radio Observations
  60. GRB 050803: PROMPT BVRcIc Observations
  61. GRB 050730, optical observation
  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. GRB050805b: MASTER optical observations
  67. Possible GRB 050805B: Swift-BAT trigger 149131 may be a burst
  68. GRB050805a: MASTER optical candidat
  69. Swift-BAT trigger 149118 is probably not a GRB
  70. GRB050802: TNG optical observations
  71. GRB 050803: RTT150 optical observations
  72. GRB050730: Radio Detection
  73. GRB050803: CrAO optical observations, possible OT candidate
  74. GRB050803: Optical/UV Upper Limits from Swift-UVOT
  75. GRB 050803: Keck Observations
  76. GRB 050802.422: Fading of the afterglow and detection of the host
  77. GRB050803: MASTER further analys
  78. GRB 050803, optical observations
  79. GRB 050803: Magellan Observations
  80. GRB 050803: early Swift XRT analysis results
  81. GRB050803: MASTER optical observations
  82. GRB050802: Tentative absorption redshift
  83. GRB050803: Swift-BAT detection of a very long burst
  84. GRB050730: FORS1 and UVES/VLT low- and high-resolution spectroscopy
  85. GRB 050802: Swift/UVOT optical and UV detections
  86. GRB050801: Unchanged decay slope
  87. GRB050802 radio non-detection
  88. GRB 050730: OHP optical observations
  89. GRB 050802: early Swift XRT analysis results
  90. GRB 050802: Swift/UVOT observations
  91. GRB050801: Optical photometry and decay index
  92. GRB 050802: XRT position
  93. GRB 050802: Swift Gamma-ray Burst
  94. GRB050801: Swift/UVOT Optical and UV detections
  95. GRB 050730: Preliminary Analysis of MIKE Spectrum
  96. GCN 050801: early Swift XRT analysis results
  97. GRB 050801, SMARTS optical/IR afterglow observations
  98. GRB 050801, afterglow observations
  99. GRB 050730, corrected photometry and break?
  100. GRB 050801: ROTSE-III Early Afterglow Break

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