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"

36155 results found.

  1. H3804: A Possible New XRB Detected by HETE
  2. XRF 050509c: Optical monitoring
  3. IBAS Alert #2512 is NOT a GRB
  4. GRB 050416(a): Host Galaxy Redshift Determination
  5. GRB 050607: MDM Observation
  6. GRB 050607 optical decay
  7. GRB 050607: RTT150 optical observations
  8. GRB 050607 : Lulin R-band observation
  9. GRB 050607: PROMPT VRcIc Observations
  10. GRB 050607: RAPTOR-S Early Optical Limits
  11. GRB 050525a, Mid-Infrared Observations
  12. GRB 050607: Optical decay and spectral slope
  13. GRB 050607: MDM Observations
  14. GRB050607,optical observation
  15. GRB 050607 - XRT refined data analysis
  16. Optical Afterglow of GRB 050607
  17. GRB050607 optical limit by "Pi of the Sky"
  18. GRB050607: Swift Detection of a long GRB
  19. GRB050607: P60 Observations
  20. GRB 050603: prediction of t_break
  21. Limits on a SN in the field of GRB 050509b
  22. GRB 050603: Redshift
  23. GRB 050603 - XRT data analysis of the first day
  24. Konus-Wind observation of GRB 050603
  25. GRB 050603: Analysis of UVOT data
  26. GRB 050603: Swift XRT Position
  27. GRB050603: Radio Detection
  28. GRB 050603: Swift-BAT refined analysis of a long three-spiked burst
  29. GRB 050603: Afterglow Identification from LCO
  30. GRB 050603: INTEGRAL shows it is not a short GRB
  31. GRB 050408: jet break in the XRT light curve
  32. GRB 050525a, infrared observations
  33. GRB 050525a, SMARTS optical/IR afterglow observations
  34. Correction to GCN Circ 3502 on GRB 050528
  35. GRB050528: updated Liverpool Telescope limits
  36. Swift-BAT GRB 050528: a soft burst
  37. Update on Swift-BAT GRB 050528 (Trigger 130679)
  38. GRB050528: BOOTES optical candidate (retraction)
  39. GRB050504: Ashra-P2/3 monitor and Ashra-AFT response
  40. GRB050528: BOOTES optical candidate
  41. Possible GRB050528: no candidate from Liverpool Telescope
  42. Swift-BAT detection of possible GRB 050528
  43. GRB050525a: Radio Observations
  44. GRB 050509b: refined XRT/Chandra afterglow position analysis
  45. GRB 050525: RTT150, Optical observations
  46. GRB050525a: optical upper limits
  47. GRB 050525a: SARA Observations
  48. GRB 050525B: Swift-BAT observations
  49. GRB 050525: MITSuME Optical Observation in VRI
  50. GRB 050525a: MDM Observations
  51. GRB050525A,optical observation
  52. GRB 050525 : Lulin optical afterglow observations
  53. GRB050525: Super-LOTIS observations
  54. GRB 050525, spectral lag pseudo-redshift
  55. GRB 050525a: Gemini/GMOS Spectra
  56. GRB050306: optical afterglow not confirmed
  57. GRB 050525: BART optical observation
  58. GRB 050525A: BOOTES simultaneous optical observations
  59. GRB 050525A: Swift-BAT refined analysis
  60. GRB050525: Optical observations
  61. GRB 050525B: INTEGRAL shows it is unrelated to GRB050525A
  62. GRB 050525: pseudo-redshift
  63. Swift/UVOT UV and optical detections of GRB 050525
  64. Konus-Wind observation of GRB 050525
  65. GRB 050525: TAROT observations of the early afterglow
  66. INTEGRAL detection of GRB 050525
  67. GRB 050525, infrared observations
  68. GRB 050525: Optical observation
  69. GRB 050525: observatons of the optical afterglow
  70. GRB050525: ROTSE-III Refined Analysis
  71. GRB 050525 - Very Bright, Not Short
  72. GRB 050525: Swift Detection of a Bright, Possibly Short Burst
  73. GRB 050525A: ROTSE-III Detection of Possible Counterpart
  74. XRF050522: NIR observations of XRT candidate
  75. XRF050522: Radio Observations
  76. GRB 050509A: Further I-band imaging
  77. GRB050522,optical observation
  78. GRB050520,optical observation
  79. XRF 050522: Continued NIR P200 Monitoring
  80. RBO Observations of GRB050522
  81. GRB050509b: optical observations
  82. Recent GRB BVRcIc field photometry
  83. GRB050520: Radio Observations
  84. XRF050522, BVRcIc field photometry
  85. XRF050522: Optical Observations
  86. XRF 050522: KAIT observations
  87. XRF 050522 detected with INTEGRAL
  88. GRB 050520: VLT/ULTRACAM observations
  89. Swift UVOT Observations of GRB 050520
  90. GRB 050520: Swift XRT refined analysis
  91. RBO Observations of GRB050520
  92. GRB 050520: P200 Observations
  93. GRB050520: Liverpool Telescope follow-up
  94. GRB 050520: TAROT optical limit
  95. GRB 050520: Swift XRT position
  96. GRB 050520: VLT/ULTRACAM observations
  97. GRB 050520: OSN optical observations
  98. GRB 050520: BART optical limit
  99. GRB 050520 - A long GRB detected with INTEGRAL
  100. Swift-BAT trigger 122203 is not a real GRB

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