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"

28058 results found.

  1. SGR1806-20: Localization by HETE
  2. HETE Fully-Automated GCN Notices
  3. GRB000301C: Late-time HST/STIS observation
  4. GRB010518: a faint BeppoSAX detection
  5. GRB000418: HST/STIS Second-epoch Observations
  6. X-ray precursors to the large flare from SGR 1900+14
  7. GRB010427, Gamma Ray Observations
  8. SGR 1900+14: No evidence of extended X-ray emission
  9. SGR 1900+14 : RXTE observations
  10. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  11. SGR 1900+14: Correction to GCN 1049
  12. GRB 010222 /corrections to VBT data
  13. Millimeter observation of SGR 1900+14
  14. SGR 1900+14: Detection of extended X-ray emission
  15. SGR 1900+14, Chandra observations
  16. SGR1900+14, I-band observations
  17. GRB010412, field photometry
  18. Giant flare from SGR1900+14
  19. GRB 010326b Optical Observations
  20. GRB010412: BeppoSAX GRBM and WFC observations
  21. GRB010324, revised field photometry
  22. REVISED LOCATION OF GRB010326A
  23. GRB 980326: Late-time HST/STIS observations
  24. GRB010324, field photometry
  25. GRB010326B, field photometry
  26. GRB010326, field photometry
  27. GRB010220, field photometry
  28. Further Optical Observations of GRB 010324
  29. GRB010222, CXO X-ray observations
  30. GRB010324, optical observations
  31. GRB010326B: Localization by HETE (2nd GRB for this date)
  32. GRB 010326 optical observations
  33. GRB010326: Refined Localization by HETE
  34. GRB010326: Localization by HETE
  35. Optical Observations of GRB 010324
  36. GRB010222, late-time optical observation
  37. Support extension to the BeppoSAX mission
  38. GRB 010222 - HEGRA GeV/TeV Observations
  39. GRB010222: Chandra X-ray Observatory Observation
  40. GRB010222: Sub-millimeter vanishing act
  41. GRB010222 - Optical observation
  42. GRB 010222, Optical Observations
  43. GRB010222 - Optical observation
  44. GRB 010222: High-Resolution Keck Spectroscopy
  45. GRB 010214, I-band data
  46. GRB 010222
  47. GRB010222 further R-band photometry
  48. GRB010222: R-band data
  49. GRB 010222: Keck Spectroscopy
  50. GRB010214, field photometry
  51. GRB010222, field photometry
  52. GRB010222 further R-band photometry
  53. GRB010222, possible increase of optical decay slope
  54. GRB 010222 Kyoto optical observation
  55. GRB010222 R-BAND OBSERVATION
  56. GRB010214 follow-up from Hanle
  57. GRB 010222: Near-IR Observations
  58. GRB 010222: Optical Observations
  59. GRB010222: Optical decay slope
  60. GRB 010214, Optical Observations
  61. GRB010222, radio observations
  62. GRB010222, optical observations
  63. GRB010222: BeppoSAX/NFI Observations
  64. GRB010214B,Gamma Ray Observations
  65. GRB 010220, simultaneous optical observations
  66. GRB010220: BeppoSAX WFC and GRBM preliminary data
  67. GRB010214, candidate optical afterglow
  68. GRB010214, optical observations
  69. GRB010214: BeppoSAX WFC and GRBM preliminary data
  70. GRB 010214: X-Ray afterglow
  71. GRB 010214 optical observation
  72. GRB010213, Radio Observations
  73. J-Band Observation of GRB 010214.
  74. GRB010213, Near-IR observations
  75. Possible InfraRed Transient of GRB 010214.
  76. GRB 010214, optical observations
  77. GRB010213 detected by HETE
  78. IPN Status Report
  79. HETE Status
  80. IPN/RXTE TRIANGULATION OF GRB010126
  81. GRB010126 Optical Observations
  82. IPN TRIANGULATION OF GRB010126
  83. Optical Observations of GRB 001018 at Keck
  84. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  85. Optical observations of GRB 001018 with JCAM
  86. IPN TRIANGULATION OF GRB010115
  87. IPN TRIANGULATION OF GRB010109
  88. IPN TRIANGULATION OF GRB010109
  89. IPN triangulation of GRB010104
  90. IPN triangulation of GRB010103
  91. H band observation of GRB 001212
  92. IPN triangulation of GRB001219
  93. GRB 001212 Optical Observation
  94. GRB 001212 Optical Observation
  95. GRB 001212 possible OA in 2MASS
  96. IPN triangulation of GRB001212
  97. Confirmation of IPN position for GRB001204
  98. IPN triangulation of GRB001204 (short/hard)
  99. GRB001120, optical observations
  100. WSRT 4.8 GHz observations of GRB001109

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