Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to https://gcn.nasa.gov.
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. GRB050713b: XRT refined analysis
  2. GRB050712: TNG R-band observations
  3. GRB 050713B: Swift-BAT Refined Analysis
  4. Swift-BAT Trigger 145729 is not a GRB
  5. GRB 050713A: Swift/UVOT observation
  6. GRB 050713A : Swift-BAT Refined Analysis
  7. GRB050712: Swift UVOT Observation of Afterglow Emission
  8. GRB 050713A : Lulin R-band observation
  9. GRB 050713A XMM-Newton observation
  10. GRB 050713b : Lulin R-band observations
  11. GRB050713B: Faulkes North Telescope observation
  12. RBO RI observations of GRB 050713A
  13. GRB 050713B
  14. GRB050709 : Chandra source optical counterpart
  15. GRB050713: Liverpool Telescope prompt observations
  16. GRB 050712, optical observations
  17. GRB 050713 : Planned XMM-Newton observation
  18. GRB050709: Candidate X-ray Afterglow from Chandra
  19. GRB 050713, R-band observations at NOT
  20. GRB 050713: ARC NIR Detections and Identification of Fading
  21. GRB050713: possible I-band afterglow
  22. GRB 050713: Swift detection of Bright Burst
  23. GRB 050713A: ROTSE-III Optical Limits
  24. GRB050712: XRT refined analysis
  25. GRB050709: Radio Observations
  26. GRB 050709: Swift UVOT and XRT observations
  27. GRB 050712: Swift-BAT Refined Analysis
  28. GRB050712: UVOT candidate optical counterpart
  29. GRB 050712: Swift XRT afterglow position
  30. GRB 050712: Swift detection of a weak burst
  31. GRB 050709: LCO40 Observations
  32. GRB050709, optical observations
  33. GRB050709: A Possible Short-Hard GRB Localized by HETE
  34. PROMPT Rc Observations of GRB 050709
  35. GRB 050525a: PROMPT VRcIc Detections
  36. GRB 050525a: ARC 3.5-meter Optical and NIR Observations
  37. GRB 050525a: ARC 3.5-Meter SPIcam Field Calibration
  38. GRB 050626 optical observations
  39. GRB 050626: Swift XRT observations
  40. GRB 050701
  41. GRB 050701, optical observations
  42. GRB 050408: ARC 3.5-meter NIR Observations
  43. GRB 050701: Refined XRT analysis
  44. Swift UVOT observations of GRB 050701
  45. GRB050701: Swift-BAT Refined analysis
  46. GRB 050701: Swift XRT afterglow position
  47. Swift trigger 143708 is really GRB 050701
  48. GRB 050607, radio observations
  49. H11603: An X-ray flare from V4641 Sgr, or a possible XRF
  50. GRB 050626 - Correction to GCN 3552
  51. GRB 050626 - a long GRB detected with INTEGRAL
  52. GRB 050525A: Swift Late-Time Decay Rate
  53. GRB050525a: HST Observations
  54. CORRECTION: GRB050603 Swift UVOT Afterglow Observations
  55. H3804: A Possible New XRB Detected by HETE
  56. H3800 and H3801 on 2005 June 11: two bursts from SGR1806-20 localized by HETE
  57. XRF 050509c: Optical monitoring
  58. Konus-Wind observation of an intermediate burst from SGR 1806-20
  59. IBAS Alert #2512 is NOT a GRB
  60. XRF050509c: Radio Detection
  61. GRB 050416(a): Host Galaxy Redshift Determination
  62. GRB 050607: MDM Observation
  63. GRB 050607 optical decay
  64. GRB 050607: RTT150 optical observations
  65. GRB050607: refined analysis of prompt REM observations
  66. Swift/UVOT observations of GRB050607
  67. GRB 050607 : Lulin R-band observation
  68. GRB 050607: PROMPT VRcIc Observations
  69. GRB 050607: RAPTOR-S Early Optical Limits
  70. GRB050607: KAIT optical limits
  71. GRB 050525a, Mid-Infrared Observations
  72. GRB 050607: Optical decay and spectral slope
  73. GRB 050607: MDM Observations
  74. GRB050607,optical observation
  75. GRB 050607 - XRT refined data analysis
  76. Optical Afterglow of GRB 050607
  77. GRB050607 optical limit by "Pi of the Sky"
  78. GRB050607: Swift Detection of a long GRB
  79. GRB050607: P60 Observations
  80. GRB050607: prompt REM observations
  81. GRB 050603: prediction of t_break
  82. Limits on a SN in the field of GRB 050509b
  83. GRB 050603: Redshift
  84. GRB 050603 - XRT data analysis of the first day
  85. Konus-Wind observation of GRB 050603
  86. GRB 050603: Analysis of UVOT data
  87. GRB050603: Fading Afterglow observed by Swift UVOT
  88. GRB050603, submillimetre observations
  89. GRB 050603: Swift XRT Position
  90. GRB050603: Radio Detection
  91. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  92. GRB 050603: Afterglow Identification from LCO
  93. GRB 050603: INTEGRAL shows it is not a short GRB
  94. Swift/BAT Detection of GRB050603
  95. GRB 050408: jet break in the XRT light curve
  96. GRB 050525a, infrared observations
  97. GRB 050525a, SMARTS optical/IR afterglow observations
  98. GRB050528, XRT observations
  99. Correction to GCN Circ 3502 on GRB 050528
  100. GRB050528: updated Liverpool Telescope limits

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