Skip to main content
Circulars over Kafka event name backfill. 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"

24662 results found.

  1. GRB010629: A Burst Localized by HETE
  2. SGR1900+14: Second Burst Localized by HETE
  3. SGR1900+14: A Burst Localized by HETE
  4. SGR1806-20: A Second, Intense Burst Localized by HETE
  5. SGR1806-20: Localization by HETE
  6. HETE Fully-Automated GCN Notices
  7. GRB000301C: Late-time HST/STIS observation
  8. GRB010518: a faint BeppoSAX detection
  9. GRB000418: HST/STIS Second-epoch Observations
  10. X-ray precursors to the large flare from SGR 1900+14
  11. GRB010427, Gamma Ray Observations
  12. SGR 1900+14: No evidence of extended X-ray emission
  13. SGR 1900+14 : RXTE observations
  14. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  15. SGR 1900+14: Correction to GCN 1049
  16. GRB 010222 /corrections to VBT data
  17. Millimeter observation of SGR 1900+14
  18. SGR 1900+14: Detection of extended X-ray emission
  19. SGR 1900+14, Chandra observations
  20. SGR1900+14, I-band observations
  21. GRB010412, field photometry
  22. Giant flare from SGR1900+14
  23. GRB 010326b Optical Observations
  24. GRB010412: BeppoSAX GRBM and WFC observations
  25. GRB010324, revised field photometry
  26. REVISED LOCATION OF GRB010326A
  27. GRB 980326: Late-time HST/STIS observations
  28. GRB010324, field photometry
  29. GRB010326B, field photometry
  30. GRB010326, field photometry
  31. GRB010220, field photometry
  32. Further Optical Observations of GRB 010324
  33. GRB010222, CXO X-ray observations
  34. GRB010324, optical observations
  35. GRB010326B: Localization by HETE (2nd GRB for this date)
  36. GRB 010326 optical observations
  37. GRB010326: Refined Localization by HETE
  38. GRB010326: Localization by HETE
  39. Optical Observations of GRB 010324
  40. GRB010222, late-time optical observation
  41. Support extension to the BeppoSAX mission
  42. GRB 010222 - HEGRA GeV/TeV Observations
  43. GRB010222: Chandra X-ray Observatory Observation
  44. GRB010222: Sub-millimeter vanishing act
  45. GRB010222 - Optical observation
  46. GRB 010222, Optical Observations
  47. GRB010222 - Optical observation
  48. GRB 010222: High-Resolution Keck Spectroscopy
  49. GRB 010214, I-band data
  50. GRB 010222
  51. GRB010222 further R-band photometry
  52. GRB010222: R-band data
  53. GRB 010222: Keck Spectroscopy
  54. GRB010214, field photometry
  55. GRB010222, field photometry
  56. GRB010222 further R-band photometry
  57. GRB010222, possible increase of optical decay slope
  58. GRB 010222 Kyoto optical observation
  59. GRB010222 R-BAND OBSERVATION
  60. GRB010214 follow-up from Hanle
  61. GRB 010222: Near-IR Observations
  62. GRB 010222: Optical Observations
  63. GRB010222: Optical decay slope
  64. GRB 010214, Optical Observations
  65. GRB010222, radio observations
  66. GRB010222, optical observations
  67. GRB010222: BeppoSAX/NFI Observations
  68. GRB010214B,Gamma Ray Observations
  69. GRB 010220, simultaneous optical observations
  70. GRB010220: BeppoSAX WFC and GRBM preliminary data
  71. GRB010214, candidate optical afterglow
  72. GRB010214, optical observations
  73. GRB010214: BeppoSAX WFC and GRBM preliminary data
  74. GRB 010214: X-Ray afterglow
  75. GRB 010214 optical observation
  76. GRB010213, Radio Observations
  77. J-Band Observation of GRB 010214.
  78. GRB010213, Near-IR observations
  79. Possible InfraRed Transient of GRB 010214.
  80. GRB 010214, optical observations
  81. GRB010213 detected by HETE
  82. IPN Status Report
  83. HETE Status
  84. IPN/RXTE TRIANGULATION OF GRB010126
  85. GRB010126 Optical Observations
  86. IPN TRIANGULATION OF GRB010126
  87. Optical Observations of GRB 001018 at Keck
  88. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  89. Optical observations of GRB 001018 with JCAM
  90. IPN TRIANGULATION OF GRB010115
  91. IPN TRIANGULATION OF GRB010109
  92. IPN TRIANGULATION OF GRB010109
  93. IPN triangulation of GRB010104
  94. IPN triangulation of GRB010103
  95. H band observation of GRB 001212
  96. IPN triangulation of GRB001219
  97. GRB 001212 Optical Observation
  98. GRB 001212 Optical Observation
  99. GRB 001212 possible OA in 2MASS
  100. IPN triangulation of GRB001212

Advanced

Download all Circulars as a .tar.gz archive:
Looking for U.S. government information and services? Visit USA.gov