Skip to main content
New! BOOM Notices and Schema v7.0.0. 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"

25841 results found.

  1. GRB020127: Chandra Observations and Prospective Counterparts
  2. pre-SN2002ap (SN/GRB?) imaging of M74
  3. GRB020124, optical observations
  4. GRB 020127, I-band observations starting 3.14-hr after the event
  5. GRB010921 Optical Observations
  6. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  7. GRB020124: Optical observations
  8. GRB020124: Optical observations
  9. GRB 020124: Optical observations
  10. GRB 020124: Optical afterglow
  11. GRB020124(=H1896): Localization of a Long GRB by HETE
  12. Possible optical counterpart to a GRB
  13. GRB011212, Optical Observations
  14. GRB011211: BeppoSAX/GRBM data
  15. Optical polarization observations for GRB011211
  16. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  17. GRB 011211, spectrum and optical photometry
  18. GRB 011130: Optical Observations of X-ray and Radio Sources
  19. GRB011212: Optical observations
  20. GRB 011212: optical observation at Asiago
  21. GRB 011211: Evidence for an Optical Break
  22. GRB 011212: optical observation at Oslo (relayed)
  23. GRB 011211, Optical Observations
  24. GRB011212, BVRI field photometry
  25. GRB011211, BVRI field photometry
  26. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  27. Fading of the optical source associated of XRF 011211
  28. GRB 011211 Optical Observations: Likely Afterglow
  29. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  30. GRB011211(=XRF011211): BeppoSAX refined positions
  31. GRB 011130: Optical Observations of Chandra sources
  32. GRB011130 (XRF011130) Chandra Observations
  33. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  34. GRB 011130, K band observations
  35. GRB011130 (=XRF011130): Second Revised Localization by HETE
  36. GRB011130 (XRF011130) SDSS PT i-band observations
  37. XRF011130: Infrared Observations
  38. GRB011130 (=XRF011130): Revised Localization of an X-ray
  39. GRB 011121
  40. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  41. GRB 011121: J-band observations
  42. GRB 011121: NIR observations, host galaxy?
  43. GRB010921 - Milagro GeV/TeV Observations
  44. GRB011121: UBRI Observations
  45. GRB011121
  46. GRB 011121: Radio Observations
  47. GRB 011121 J-Band Astrometry
  48. GRB 011121: Detection of Bright IR Counterpart
  49. GRB011121: possible redshift, continued decay
  50. GRB011121: BeppoSAX-WFC refined positions
  51. IPN triangulation of GRB011121
  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 I-band Observation
  57. The X-ray Flash 011030 ('GRB 011030')
  58. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  59. GRB 970828: HST Observations of the Host Galaxy
  60. GRB 000131: HST Detection of the Host Galaxy
  61. GRB 970828: HST Observations of the Host Galaxy
  62. GRB010921, optical observation
  63. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  64. GRB011019: Subaru Optical Observations
  65. GRB010921, optical observations
  66. GRB011030 - further refinement WFC position
  67. GRB011030: radio search
  68. GRB 011030, R-band observations
  69. GRB 010921: Possible supernova component
  70. GRB011019: ROTSE-III optical observations
  71. GRB010921, optical observation at early time
  72. GRB 010921, I-band observations
  73. GRB011019, optical observations
  74. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  75. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  76. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  77. GRB010923 as seen by BeppoSAX GRBM
  78. GRB010928(=H1770): Localization of a Long GRB by HETE
  79. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  80. GRB010921, negative optical observations
  81. GRB010921 field photometry
  82. H1761: A Bright GRB Detected by HETE
  83. HETE Trigger #1760 (GRB 010920B?): a new optical source
  84. GRB000926, Host Galaxy Observations
  85. GRB001109, Host Galaxy Spectroscopic Observations
  86. Probable SGR or Short Duration GRB Detected by HETE
  87. GRB 010222: HST observations -- host galaxy and late-time decay
  88. BeppoSAX/GRBM detection of GRB 010801
  89. GCN and HETE status
  90. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  91. GRB 010222 - WHT BVRI images
  92. SGR1900+14 burst seen by HETE: BeppoSAX data
  93. GRB 010629 Optical Observations
  94. SGR1900+14: High Fluence Burst Localized by HETE
  95. GRB010629, optical observations
  96. IPN triangulation of GRB010629
  97. GRB010629: A Burst Localized by HETE
  98. SGR1900+14: Second Burst Localized by HETE
  99. SGR1900+14: A Burst Localized by HETE
  100. Possible burst from SGR1806-20

Advanced

Download all Circulars as a .tar.gz archive:
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