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"

28068 results found.

  1. Color indices of the afterglow of GRB011211
  2. GRB011212: Optical observations at Gunma
  3. GRB 011211, spectrum and optical photometry
  4. GRB 011211: Evidence for an Optical Break
  5. GRB 011211: TNG Spectroscopic Observations
  6. optical follow-up of GRB(XRF) 011211
  7. GRB 011212: optical observation at Oslo (relayed)
  8. GRB 011211, Optical Observations
  9. GRB011212: Optical observations
  10. GRB 011211: BVRi-band photometry
  11. GRB 011211 Optical Observations: Likely Afterglow
  12. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  13. GRB 011130: Magellan spectroscopy
  14. Sub-mm and Centimeter Detections of the Host Galaxy of GRB000418
  15. GRB011130, optical observations
  16. GRB 011130, K band observations
  17. GRB011130, optical observations
  18. Detection of the X-ray afterglow of GRB011121 by BeppoSAX
  19. GRB011130 (=XRF011130): Revised Localization of an X-ray
  20. GRB001109, Radio Monitoring
  21. GRB 011121
  22. GRB 011121: J-band observations
  23. GRB 011121: NIR observations, host galaxy?
  24. GRB010921 - Milagro GeV/TeV Observations
  25. GRB 011121: HST Scheduled
  26. GRB011121: fainter still
  27. GRB 011121: Radio Observations
  28. GRB011121: continued decay
  29. GRB 011121: Detection of Bright IR Counterpart
  30. GRB011121: possible redshift, continued decay
  31. GRB011121: fading behavior
  32. GRB011121: possible optical counterpart
  33. GRB 011030 I-band Observation
  34. The X-ray Flash 011030 ('GRB 011030')
  35. The Radio Afterglow from the X-ray Rich GRB 011030
  36. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  37. GRB 000131: HST Detection of the Host Galaxy
  38. GRB010921, optical observation
  39. GRB 011030 I-band Observations
  40. GRB 011030 K-band Observations
  41. GRB 010921: Possible supernova component
  42. GRB011019: ROTSE-III optical observations
  43. GRB010921, optical observation at early time
  44. GRB010921: Spectroscopy of the Host Galaxy
  45. GRB 010921: The afterglow of HETE #1761
  46. GRB010928(=H1770): Localization of a Long GRB by HETE
  47. GRB010921, negative optical observations
  48. GRB010921 field photometry
  49. BeppoSAX/GRBM detection of GRB 010801
  50. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  51. BeppoSAX/GRBM detection of GRB010728
  52. GRB 010222 - WHT BVRI images
  53. GRB 010629 Optical Observations
  54. SGR1900+14: High Fluence Burst Localized by HETE
  55. GRB010629: A Burst Localized by HETE
  56. SGR1900+14: Second Burst Localized by HETE
  57. SGR1900+14: A Burst Localized by HETE
  58. IPN detection of SGR1900+14
  59. SGR1806-20: A Second, Intense Burst Localized by HETE
  60. SGR1806-20: Localization by HETE
  61. GRB000301C: Late-time HST/STIS observation
  62. GRB010518: a faint BeppoSAX detection
  63. GRB000418: HST/STIS Second-epoch Observations
  64. SGR 1900+14: No evidence of extended X-ray emission
  65. GRB 010222 /corrections to VBT data
  66. SGR 1900+14: Detection of extended X-ray emission
  67. GRB010412, field photometry
  68. GRB 980326: Late-time HST/STIS observations
  69. Further Optical Observations of GRB 010324
  70. GRB010222, late-time optical observation
  71. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  72. GRB010222: Chandra X-ray Observatory Observation
  73. GRB 010222, Optical Observations
  74. GRB 010222: High-Resolution Keck Spectroscopy
  75. GRB 010214, I-band data
  76. Sub-millimeter Excess/GRB 010222
  77. GRB 010222 HST/Chandra TOO
  78. GRB010222: R-band data
  79. GRB010222, possible increase of optical decay slope
  80. GRB 010222 Kyoto optical observation
  81. GRB010222: fading behavior
  82. GRB 010220: Near-IR Observations
  83. GRB010214 follow-up from Hanle
  84. GRB010222: Another absorption line system
  85. GRB010222: Optical decay slope
  86. GRB010222: Sub-millimeter detection
  87. GRB010222: R-band fading behavior
  88. GRB010222: Optical Observations
  89. GRB010222: possible optical counterpart
  90. GRB010220, Radio and Optical Observations
  91. GRB010214, candidate optical afterglow
  92. GRB 010214: X-Ray afterglow
  93. GRB010213, Radio Observations
  94. GRB010213 Optical Observation
  95. GRB010213, Radio Observations
  96. J-Band Observation of GRB 010214.
  97. GRB010214 Optical Observation
  98. GRB010214: BeppoSAX/NFI Observations
  99. GRB 010214, optical observations
  100. IPN Status Report

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