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"

22063 results found.

  1. GRB 011030 I-band Observations
  2. GRB 011030 K-band Observations
  3. GRB010921, optical observations
  4. GRB 011030, WSRT radio observations
  5. GRB 011030, Radio observations
  6. GRB 011030, R-band observations
  7. GRB 010921: Possible supernova component
  8. GRB011019: NEAT Optical Observations
  9. GRB011019: ROTSE-III optical observations
  10. GRB 010921, I-band observations
  11. GRB011019: Optical observations
  12. GRB011019, optical observations -- correction
  13. GRB011019, optical observations
  14. GRB 010921: The afterglow of HETE #1761
  15. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  16. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  17. GRB010928(=H1770): Localization of a Long GRB by HETE
  18. GRB010921, negative optical observations
  19. GRB010921 Optical Observations
  20. GRB 010921 DPOSS Images Available
  21. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  22. HETE Trigger #1760 (GRB 010920B?): a new optical source
  23. HETE Trigger #1759 (GRB 010920?) optical observations
  24. GRB000926, Host Galaxy Observations
  25. GRB001109, Host Galaxy Spectroscopic Observations
  26. GRB000926 Host Galaxy Observations
  27. GRB 010222: HST observations -- host galaxy and late-time decay
  28. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  29. GRB 010222 - WHT BVRI images
  30. GRB 010629 Optical Observations
  31. GRB010629: Optical Observations
  32. SGR1900+14: High Fluence Burst Localized by HETE
  33. GRB010629, optical observations
  34. GRB010629: A Burst Localized by HETE
  35. SGR1900+14: Second Burst Localized by HETE
  36. SGR1900+14: A Burst Localized by HETE
  37. SGR1806-20: A Second, Intense Burst Localized by HETE
  38. GRB 00630: Host Galaxy
  39. SGR1806-20: Localization by HETE
  40. GRB000418: HST/STIS Second-epoch Observations
  41. GRB010214, optical observations
  42. GRB010427, Gamma Ray Observations
  43. SGR 1900+14: No evidence of extended X-ray emission
  44. SGR 1900+14 : RXTE observations
  45. GRB 010222 /corrections to VBT data
  46. Millimeter observation of SGR 1900+14
  47. Chandra Observations of SGR 1900+14
  48. SGR 1900+14, Chandra observations
  49. Chandra Observations of SGR 1900+14
  50. SGR1900+14, I-band observations
  51. GRB 010326b Optical Observations
  52. GRB010412: Optical observations
  53. GRB010412: Optical observations
  54. GRB010412: BeppoSAX GRBM and WFC observations
  55. GRB Observation Report
  56. GRB 980326: Late-time HST/STIS observations
  57. GRB010326B, field photometry
  58. Further Optical Observations of GRB 010324
  59. GRB010222, CXO X-ray observations
  60. GRB 010326A: Further optical observations
  61. GRB 010326B: Optical observations
  62. GRB010324, optical observations
  63. GRB010326B: Localization by HETE (2nd GRB for this date)
  64. GRB 010326: Optical observations
  65. GRB 010326 optical observations
  66. GRB010326: Refined Localization by HETE
  67. GRB010326: Localization by HETE
  68. Optical Observations of GRB 010324
  69. IPN TRIANGULATION OF GRB010324
  70. GRB990705, VLT-FORS1 observations of the host galaxy
  71. GRB 010222 - HEGRA GeV/TeV Observations
  72. GRB010222: Sub-millimeter vanishing act
  73. GRB 010222, Optical Observations
  74. GRB 010214, I-band data
  75. Sub-millimeter Excess/GRB 010222
  76. GRB 010222
  77. GRB 010222 HST/Chandra TOO
  78. GRB010222 further R-band photometry
  79. GRB010222 Optical observations
  80. GRB010222, field photometry
  81. GRB010222 further R-band photometry
  82. GRB010222, possible increase of optical decay slope
  83. GRB 010222 BV optical observations
  84. GRB010220, Optical Observations
  85. GRB010222 R-BAND OBSERVATION
  86. GRB 010220: Near-IR Observations
  87. GRB010214 follow-up from Hanle
  88. GRB 010222: Near-IR Observations
  89. GRB 010222: Optical Observations
  90. GRB010222: Optical decay slope
  91. GRB 010214, Optical Observations
  92. GRB010222: Sub-millimeter detection
  93. GRB010222: R-band fading behavior
  94. GRB010222: Optical Observations
  95. GRB010222, radio observations
  96. GRB010222, optical observations
  97. GRB010222: BeppoSAX/NFI Observations
  98. GRB010214B,Gamma Ray Observations
  99. GRB010222
  100. GRB010220, Radio and Optical Observations

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