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"

28059 results found.

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