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"

35958 results found.

  1. GRB050123: optical limit 1.8h before GRB
  2. GRB050123,optical observation
  3. GRB 050123: KAIT observations
  4. GRB050123: P60 Observations
  5. GRB 050123(=H3666): A GRB Localized in Real Time by HETE
  6. CFHTLS optical transient unlikely to be a GRB
  7. Unusual optical transient (GRB ???)
  8. GRB050117a: Radio Observations
  9. GRB 041224 and GRB 041226: BOOTES-2 simultaneous observations
  10. GRB 050117, I-band observations
  11. GRB 050117: Optical observation
  12. GRB050117: Refined XRT position
  13. GRB050117: MASTER optical observations
  14. MASTER:GRB050117 SWIFT
  15. GRB050117: Swift-BAT detection of a long multi-peaked burst
  16. Triangulation of Short Hard GRB050112 (large error box)
  17. SGR1806: Optical Transient Candidates in SOHO/LASCO Images
  18. SGR 1806-20 and extragalactic short-duration GRBs
  19. SGR 1806-20: Temporal and Spectral behavior of radio transient
  20. SGR 1806-20, RHESSI observations of the 041227 giant flare
  21. SGR1806: Detection of a Sudden Ionospheric Disturbance
  22. GRB 041217: Optical observations
  23. GRB041219, early time observations
  24. IPN localization of giant flare from SGR1806-20
  25. GRB041219; RXTE ASM Observations
  26. NIR Observations of GRB 041219
  27. GRB041223: decay of the afterglow
  28. GRB 041224: near-infrared observations with REM
  29. GRB 041223: XRT afterglow spectrum and light curve
  30. GRB 041223 Fluence measured by Swift-BAT
  31. GRB041223: optical and NIR observations with REM
  32. GRB 041219: TAROT optical observations
  33. GRB 041218: TAROT optical observations
  34. GRB 041223: J-band observations of the afterglow
  35. GRB 041223: Detection of Optical Transient with LCO40
  36. GRB 041219c: PROMPT Observations
  37. GRB 041218: optical observations
  38. GRB 041219: Second Epoch WSRT Radio Observations
  39. GRB 041219: WSRT Radio Afterglow Detection
  40. GRB 041219: Keck IR Observations and Astrometric Refinement of the
  41. GRB 041218: Optical observations
  42. GRB 041219 : optical follow-up observations
  43. Deep RAPTOR observations during GRB 041219
  44. GRB 041218 Optical Observations
  45. GRB 041219 Optical Observations
  46. GRB041219c: Third Burst in One Day from Swift-BAT
  47. GRB041219: Optical Afterglow Detection
  48. GRB041219: Continued NIR Observations
  49. GRB 041219 ,optical observation
  50. GRB 041219: Radio Afterglow Detection
  51. GRB 041218 : Radio Observations
  52. GRB 041218: R-band optical observations
  53. GRB041219: Confirmed NIR Afterglow
  54. GRB041218: Continued P60 Optical Observations
  55. GRB 041218: Optical Observation
  56. GRB 041219: Infrared Afterglow Candidate
  57. GRB041219, BVRcIc field calibration
  58. GRB 041219: Infrared Afterglow Candidate
  59. GRB041218, BVRcIc field calibration
  60. GRB041219: Prompt Optical Observations from ROTSE-IIIb
  61. GRB041219: P60 Optical Observations
  62. GRB 041219 - A long GRB detected by INTEGRAL
  63. GRB 041219: PAIRITEL IR Observations, < 3 minutes after trigger
  64. GRB 041217: PROMPT Observations
  65. GRB041218: optical observations
  66. GRB041217: optical limit 30 min after GRB
  67. GRB 041218; optical candidate
  68. GRB 041218: Optical observations
  69. GRB 041217: LCO40 Optical Observations and Possible Candidates
  70. GRB 041218 - A long GRB detected by integral
  71. GRB041217: Optical Observations
  72. GRB041217: P60 Optical Observations
  73. GRB041217: Infrared Observations
  74. GRB041217: The First GRB Located On-Board Swift
  75. GRB041211: Faulkes Telescope continued optical monitoring
  76. Optical Transient in Lynx not a GRB
  77. Optical transient (GRB?) in Lynx
  78. Optical transient (GRB?) in Lynx, UT Dec 11.4436
  79. GRB041211: Continued P60 Observations
  80. GRB041211: RAPTOR observations
  81. GRB041211: Ashra Prototype optical observation
  82. GRB041211, Faulkes Telescope optical observation
  83. GRB041211, BVRcIc field calibration
  84. GRB 041211: Infrared Observations
  85. GRB 041211: KAIT observations
  86. GRB 041211: Optical follow-up in East Asian region
  87. GRB 041211(=H3622): A Long GRB Localized by the HETE WXM and SXC
  88. GRB041211: P60 optical imaging
  89. GRB970815: Discovery of Optical Afterglow
  90. Distribution of IBAS Alerts for NON-GRB sources
  91. Triangulation of short GRB 041116 (large error box)
  92. GRB 040924: Afterglow Color
  93. GRB 041006: GETS Optical Afterglow Observation
  94. Summary of the recent bursts from SGR 1806-20
  95. GRB 041006: Optical Observations
  96. GRB041006, late-time optical photometry
  97. IBAS GRB Alert # 2034
  98. GRB041006: RTT150 Optical Observations
  99. Bright bursts from SGR1806-20
  100. GRB 041016: BOOTES-2 simultaneous observation

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