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. IPN Upper Limits to a GRB Associated With SN2002ap
  2. GRB020124 BVRI field photometry
  3. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  4. SN2002ap (SN/GRB?) Echelle spectra
  5. GRB020127 Optical Observations
  6. SN 2002ap in M74
  7. SN2002ap (SN/GRB?) UBVRI Field Photometry
  8. GRB020127: Chandra Observations and Prospective Counterparts
  9. pre-SN2002ap (SN/GRB?) imaging of M74
  10. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  11. GRB020124, optical observations
  12. GRB 020127, I-band observations starting 3.14-hr after the event
  13. GRB010921 Optical Observations
  14. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  15. GRB020124: Optical observations
  16. GRB 020124: Optical observations
  17. GRB 020124: Optical afterglow
  18. GRB020124(=H1896): Localization of a Long GRB by HETE
  19. Possible optical counterpart to a GRB
  20. GRB011212, Optical Observations
  21. Optical polarization observations for GRB011211
  22. GRB 011211: Detection of the Probable Host Galaxy
  23. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  24. GRB 011130: Optical Observations of X-ray and Radio Sources
  25. GRB 011212: optical observation at Asiago
  26. GRB 011211: Evidence for an Optical Break
  27. GRB 011211: TNG Spectroscopic Observations
  28. optical follow-up of GRB(XRF) 011211
  29. GRB 011212: optical observation at Oslo (relayed)
  30. GRB 011211, Optical Observations
  31. GRB011212, BVRI field photometry
  32. GRB011211, BVRI field photometry
  33. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  34. Fading of the optical source associated of XRF 011211
  35. GRB 011211 Optical Observations: Likely Afterglow
  36. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  37. GRB011130 (XRF011130) Chandra Observations
  38. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  39. GRB 011130, K band observations
  40. GRB011130, optical observations
  41. GRB011130 (=XRF011130): Second Revised Localization by HETE
  42. GRB011130 (XRF011130) SDSS PT i-band observations
  43. XRF011130: Infrared Observations
  44. GRB 011121
  45. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  46. GRB 011121: J-band observations
  47. GRB 011121: NIR observations, host galaxy?
  48. GRB011121: UBRI Observations
  49. GRB 011121 J-Band Astrometry
  50. GRB 011121: Detection of Bright IR Counterpart
  51. GRB011121: possible redshift, continued decay
  52. GRB 011030: TNG K-band observation
  53. XRF011030: J and K band observations
  54. XRF011030: Chandra Observations
  55. GRB011030: Z-band observations
  56. GRB 011030 R band observations
  57. GRB 011030 I-band Observation
  58. The X-ray Flash 011030 ('GRB 011030')
  59. Non-triggered burst 011030 ("GRB 011030")
  60. The Radio Afterglow from the X-ray Rich GRB 011030
  61. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  62. GRB 970828: HST Observations of the Host Galaxy
  63. GRB 000131: HST Detection of the Host Galaxy
  64. GRB 970828: HST Observations of the Host Galaxy
  65. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  66. GRB011019: Subaru Optical Observations
  67. GRB 011030 I-band Observations
  68. GRB 011030 K-band Observations
  69. GRB010921, optical observations
  70. GRB011030 - further refinement WFC position
  71. GRB 011030, Radio observations
  72. GRB011030: radio search
  73. GRB 010921: Possible supernova component
  74. GRB010921, optical observation at early time
  75. GRB 010921, I-band observations
  76. GRB011019, optical observations
  77. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  78. GRB 010921: The afterglow of HETE #1761
  79. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  80. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  81. GRB010923 as seen by BeppoSAX GRBM
  82. GRB010928(=H1770): Localization of a Long GRB by HETE
  83. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  84. GRB010921, negative optical observations
  85. GRB010921 field photometry
  86. H1761: A Bright GRB Detected by HETE
  87. GRB000926, Host Galaxy Observations
  88. GRB001109, Host Galaxy Spectroscopic Observations
  89. Probable SGR or Short Duration GRB Detected by HETE
  90. GCN and HETE status
  91. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  92. GRB 010222 - WHT BVRI images
  93. SGR1900+14 burst seen by HETE: BeppoSAX data
  94. GRB 010629 Optical Observations
  95. SGR1900+14: High Fluence Burst Localized by HETE
  96. GRB010629, optical observations
  97. GRB010629: A Burst Localized by HETE
  98. SGR1900+14: Second Burst Localized by HETE
  99. SGR1900+14: A Burst Localized by HETE
  100. SGR1806-20: A Second, Intense Burst Localized by HETE

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