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"

3115 results found.

  1. XRF030723 (=H2777): An X-ray Flash Localized by the HETE WXM and
  2. IPN triangulation of GRB030715 (two large error boxes)
  3. GRB030329 -- RATAN-600 data in April-May
  4. GRB 030329: Optical limit (contemporaneous imaging)
  5. XRF030416 (=U10897): An X-Ray Flash Localized by the HETE WXM
  6. IPN triangulation of GRB030425 (single error box)
  7. GRB 030329, the review of the sky area in plate archive (1950-1998)
  8. IPN triangulation of GRB030422 (two large error boxes)
  9. GRB030329: 444 AAVSO Measurements
  10. GRB 030329, nearby galaxies
  11. Further AAVSO V,B,R observations of GRB030329
  12. GRB 030329: Correction to GCN 2056
  13. GRB 030329: optical observations
  14. GRB030323, ROTSE-III detection of possible optical counterpart
  15. GRB030323, possible optical counterpart
  16. IPN triangulation of GRB030320 (small error box)
  17. GRB030226 (=U10893): A Long GRB Localized by the HETE WXM and SXC
  18. GRB 030217: Optical Observations at 4, 5, and 6 Days
  19. GRB030131: Kiso Observations
  20. IPN triangulation of GRB030101 (two large error boxes)
  21. GRB021004, late time optical observations
  22. Improved IPN error box for GRB021125
  23. IPN BURST POSITION
  24. IPN triangulation of GRB021125 (INTEGRAL BURST)
  25. GRB021104(=H2434): A Long, X-Ray-Rich GRB Localized by HETE
  26. GRB021104: optical observations
  27. GRB021104: possible optical afterglow
  28. IPN triangulation of GRB021027 (single large error box)
  29. GRB021004, late-time optical observations
  30. GRB 021004: optical observations
  31. IPN triangulation of GRB021020
  32. GRB021016(=H2397): A Long GRB Localized by HETE
  33. IPN triangulation of GRB021016 (small error box)
  34. IPN triangulation of GRB021008 (two small error boxes)
  35. GRB021004: optical observations and predicted break time
  36. GRB021004: BVRc photometry
  37. GRB 021004: optical counterpart
  38. GRB 021004, SPM optical observations
  39. IPN triangulation of GRB020923 (two error boxes)
  40. Confirmation of IPN error box for GRB020910
  41. IPN triangulation of GRB020910
  42. GRB020903(=H2314): An X-Ray Flash Localized by HETE
  43. INTEGRAL GRBs added to GCN
  44. IPN error box for GRB020813
  45. GRB020813: Candidate Optical Afterglow
  46. Correction to IPN error box for GRB020706
  47. GRB 020625, optical observations
  48. GRB 020531: optical photometry of Chandra sources
  49. GRB020604, optical observations
  50. GRB020531: Observations with the Chandra X-ray Observatory
  51. Correction to IPN triangulation of GRB020603 (possible short/hard burst)
  52. GRB 020124: Optical observations
  53. GRB 020331 Kyoto observation on March 31
  54. GRB020317: optical observations
  55. GRB020321 optical observations
  56. IPN Upper Limits to a GRB Associated With SN2002ap
  57. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  58. GRB020127: Chandra Observations and Prospective Counterparts
  59. GRB 011211, Optical Observations
  60. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  61. GRB011130 (XRF011130) Chandra Observations
  62. GRB011121: fainter still
  63. BEPPOSAX GRB011121
  64. XRF011030: Chandra Observations
  65. Millimeter observation of SGR 1900+14
  66. IPN Triangulation of GRB010412
  67. GRB010214, candidate optical afterglow
  68. GRB010214 Optical Observation
  69. IPN TRIANGULATION OF GRB010109
  70. IPN TRIANGULATION OF GRB010109
  71. XMM-Newton observation of GRB001025
  72. IPN TRIANGULATION OF GRB001020
  73. IPN TRIANGULATION OF GRB001018
  74. GRB000926 - Amateur Optical Observations
  75. GRB 000926 Chandra Observation
  76. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  77. J and K band observations of GRB 000926
  78. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  79. GRB 000926, Optical Observation
  80. GRB 000926: Optical candidate
  81. Optical candidate for GRB000926
  82. GRB000911: Sub-millimeter observations
  83. IPN localization of GRB000812
  84. IPN localization of GRB000811
  85. GRB 000630: Detection of the Optical Afterglow
  86. GRB000630, Revised BVRI Field Photometry
  87. GRB000630, Optical Observations
  88. GRB000630: Optical observations
  89. possible optical counterpart of GRB 000630
  90. IPN triangulation of GRB000630
  91. GRB 000408, optical observations
  92. Radio observations of the error box of GRB000301A
  93. GRB000301A [IPN Position]
  94. GRB000226 [IPN Position]
  95. IPN localization of GRB991226
  96. GRB991216 Optical and infrared observations of Beethoven Burst
  97. GRB991216 ('Beethoven Burst') B, R, and K Observations
  98. IPN localization of GRB991208
  99. IPN localization of GRB991105
  100. IPN localization of GRB991014 - CORRECTION

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