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"
  1. GRB 060109: Swift Detection of a long burst
  2. GRB 060108: a dark burst?
  3. GRB 060108: Refined XRT analysis
  4. GRB 060108: VLT J-band observations
  5. GRB 060108: Mitsume optical observations
  6. GRB 060108: Swift/UVOT upper limits
  7. GRB 060105: quick look analysis of the Suzaku/XIS afterglow observation
  8. GRB060108: SDSS pre-burst observations
  9. GRB060108: Faulkes Telescope observation
  10. GRB060108, optical observation
  11. GRB 060108: Refined analysis of the Swift-BAT burst
  12. GRB 060108: Swift XRT position
  13. GRB060108: Swift detection of its 100th GRB
  14. GRB 060105: pseudo-z from spectral parameters of the prompt emission
  15. GRB 060105: Radio observations
  16. GRB 060105: MDM Observation
  17. Konus-Wind observation of GRB 060105
  18. GRB 060105: ISAS observations and near IR upper limit
  19. GRB 060105: Swift/UVOT upper limits
  20. GRB 060105: Mitsume optical observations
  21. GRB 060105: BAT refined analysis
  22. GRB 060102 - no XRT afterglow
  23. GRB 060105: XRT refined analysis
  24. GRB060105: Suzaku-XIS and -HXD observation plan
  25. GRB060105, optical observation
  26. GRB060105 : Kiso optical observation
  27. GRB060105: Swift detection of a bright long burst
  28. Swift-BAT trigger 175653 is not an astrophysical source
  29. GRB 060102: MDM Observation
  30. Swift-BAT trigger 175653 is probably not a GRB
  31. GRB 060102: Swift-BAT refined analysis
  32. Time Correction to GRB 060102
  33. GRB 060102: Swift-BAT detection of a burst
  34. GRB051211B: optical observations
  35. GRB051227: SARA Observations
  36. GRB 051221B: Optical Observations with Kuiper 1.54m
  37. GRB 051227: Likely host galaxy underlying afterglow position
  38. GRB 051227: optical observation
  39. GRB051221B: Radio observations
  40. GRB 051221A: VLA Radio Observations
  41. GRB051227: Radio Observations
  42. GRB 051227: Confirmed fading from Gemini observations
  43. GRB051227: further analysis of VLT images
  44. GRB 051227: optical afterglow
  45. GRB 051227: Swift/UVOT Upper Limits (Possible U-band
  46. GRB 051227: Gemini observations
  47. GRB 051227: Keck Spectroscopy
  48. GRB 051227: Magellan r'-band Imaging/Astrometry
  49. GRB 051227: refined analysis of VLT images
  50. GRB 051227: P60 Observations
  51. GRB 051227: MDM Observation
  52. GRB 051227: R-band object in the XRT error circle
  53. GRB 051227: Joint Swift-HETE Spectral Analysis
  54. GRB 051227: XRT refined analysis
  55. GRB 051227: Further analysis of the Swift-BAT burst
  56. GRB 051227: Refined analysis of the Swift-BAT burst
  57. GRB051227: SDSS pre-burst observations
  58. GRB 051227, optical observation
  59. GRB 051227: Swift detection of a burst
  60. GRB051117B: optical observation
  61. IBAS_alert n. 2719 : not a real GRB
  62. Konus-Wind observation of GRB 051221A
  63. GRB051221A: Suzaku WAM observation of the prompt emission
  64. GRB 051221A: MDM Optical Observations
  65. GRB051016: analysis of the XMM-Newton observation
  66. GRB 051221A: Detection at 251nm with Swift UVOT
  67. GRB 051221A: Chandra Afterglow Position
  68. GRB 051221A: Refined spectral and temporal analysis of the Swift-BAT short hard burst
  69. GRB 051221B: ROTSE-III Optical Limits
  70. GRB 051221B: TAROT optical limits
  71. GRB 051221A: WSRT Radio Observations
  72. GRB 051221: Redshift from Gemini
  73. GRB 051221: Continued fading of optical afterglow
  74. GRB 051221B: Refined analysis of the Swift-BAT burst
  75. Possible GRB 051221B: MDM Optical Detection
  76. GRB 051221A: RAPTOR Fading Counterpart Constraint
  77. GRB 051221B: BOOTES optical observations.
  78. Possible GRB 051221B: Swift XRT position
  79. GRB 051211A: Evidence This Is a Short Burst from Analysis of Spectral
  80. Swift-BAT detection of a possible burst
  81. GRB 051221: Discovery of fading optical afterglow
  82. GRB 051221: Swift XRT refined analysis
  83. GRB 051221: Swift/UVOT upper limits
  84. GRB 051221: Possible nearby cluster
  85. GRB 051221: No variability in Gemini data
  86. GRB 051221: Correction to GCN #4368
  87. GRB 051221: Gemini observations
  88. GRB 051221: Improved astrometry of the IR counterpart
  89. GRB051221: K-band source
  90. GRB 051221: XRT position
  91. GRB 051221: Refined analysis of the Swift-BAT short hard burst
  92. GRB 051221: IR Observations at GRB+1hr
  93. GRB 051221: Swift detection of a bright short burst
  94. Refined analysis of the SWIFT J1626.6-5156
  95. Swift-BAT discovery of hard x-ray transient SWIFT J1626.6-5156
  96. Refined analysis of the Swift-BAT detection of the RS CVn star II Peg
  97. GRB051211A (=H3979): Refined Analysis
  98. GRB 051211B: optical afterglow
  99. Swift detection of an RS CVn flare star
  100. GRB051211A: possible optical candidate

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