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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"

24775 results found.

  1. GRB010921, negative optical observations
  2. GRB010921 field photometry
  3. H1761: A Bright GRB Detected by HETE
  4. GRB000926, Host Galaxy Observations
  5. GRB001109, Host Galaxy Spectroscopic Observations
  6. Probable SGR or Short Duration GRB Detected by HETE
  7. GCN and HETE status
  8. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  9. GRB 010222 - WHT BVRI images
  10. SGR1900+14 burst seen by HETE: BeppoSAX data
  11. GRB 010629 Optical Observations
  12. SGR1900+14: High Fluence Burst Localized by HETE
  13. GRB010629, optical observations
  14. GRB010629: A Burst Localized by HETE
  15. SGR1900+14: Second Burst Localized by HETE
  16. SGR1900+14: A Burst Localized by HETE
  17. SGR1806-20: A Second, Intense Burst Localized by HETE
  18. SGR1806-20: Localization by HETE
  19. HETE Fully-Automated GCN Notices
  20. GRB000301C: Late-time HST/STIS observation
  21. GRB010518: a faint BeppoSAX detection
  22. GRB000418: HST/STIS Second-epoch Observations
  23. X-ray precursors to the large flare from SGR 1900+14
  24. GRB010427, Gamma Ray Observations
  25. SGR 1900+14: No evidence of extended X-ray emission
  26. SGR 1900+14 : RXTE observations
  27. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  28. SGR 1900+14: Correction to GCN 1049
  29. GRB 010222 /corrections to VBT data
  30. Millimeter observation of SGR 1900+14
  31. SGR 1900+14: Detection of extended X-ray emission
  32. SGR 1900+14, Chandra observations
  33. SGR1900+14, I-band observations
  34. GRB010412, field photometry
  35. Giant flare from SGR1900+14
  36. GRB 010326b Optical Observations
  37. GRB010412: BeppoSAX GRBM and WFC observations
  38. GRB010324, revised field photometry
  39. REVISED LOCATION OF GRB010326A
  40. GRB 980326: Late-time HST/STIS observations
  41. GRB010324, field photometry
  42. GRB010326B, field photometry
  43. GRB010326, field photometry
  44. GRB010220, field photometry
  45. Further Optical Observations of GRB 010324
  46. GRB010222, CXO X-ray observations
  47. GRB010324, optical observations
  48. GRB010326B: Localization by HETE (2nd GRB for this date)
  49. GRB 010326 optical observations
  50. GRB010326: Refined Localization by HETE
  51. GRB010326: Localization by HETE
  52. Optical Observations of GRB 010324
  53. GRB010222, late-time optical observation
  54. Support extension to the BeppoSAX mission
  55. GRB 010222 - HEGRA GeV/TeV Observations
  56. GRB010222: Chandra X-ray Observatory Observation
  57. GRB010222: Sub-millimeter vanishing act
  58. GRB010222 - Optical observation
  59. GRB 010222, Optical Observations
  60. GRB010222 - Optical observation
  61. GRB 010222: High-Resolution Keck Spectroscopy
  62. GRB 010214, I-band data
  63. GRB 010222
  64. GRB010222 further R-band photometry
  65. GRB010222: R-band data
  66. GRB 010222: Keck Spectroscopy
  67. GRB010214, field photometry
  68. GRB010222, field photometry
  69. GRB010222 further R-band photometry
  70. GRB010222, possible increase of optical decay slope
  71. GRB 010222 Kyoto optical observation
  72. GRB010222 R-BAND OBSERVATION
  73. GRB010214 follow-up from Hanle
  74. GRB 010222: Near-IR Observations
  75. GRB 010222: Optical Observations
  76. GRB010222: Optical decay slope
  77. GRB 010214, Optical Observations
  78. GRB010222, radio observations
  79. GRB010222, optical observations
  80. GRB010222: BeppoSAX/NFI Observations
  81. GRB010214B,Gamma Ray Observations
  82. GRB 010220, simultaneous optical observations
  83. GRB010220: BeppoSAX WFC and GRBM preliminary data
  84. GRB010214, candidate optical afterglow
  85. GRB010214, optical observations
  86. GRB010214: BeppoSAX WFC and GRBM preliminary data
  87. GRB 010214: X-Ray afterglow
  88. GRB 010214 optical observation
  89. GRB010213, Radio Observations
  90. J-Band Observation of GRB 010214.
  91. GRB010213, Near-IR observations
  92. Possible InfraRed Transient of GRB 010214.
  93. GRB 010214, optical observations
  94. GRB010213 detected by HETE
  95. IPN Status Report
  96. HETE Status
  97. IPN/RXTE TRIANGULATION OF GRB010126
  98. GRB010126 Optical Observations
  99. IPN TRIANGULATION OF GRB010126
  100. Optical Observations of GRB 001018 at Keck

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