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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"

25280 results found.

  1. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  2. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  3. GRB010923 as seen by BeppoSAX GRBM
  4. GRB010928(=H1770): Localization of a Long GRB by HETE
  5. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  6. GRB010921, negative optical observations
  7. GRB010921 field photometry
  8. H1761: A Bright GRB Detected by HETE
  9. GRB000926, Host Galaxy Observations
  10. GRB001109, Host Galaxy Spectroscopic Observations
  11. Probable SGR or Short Duration GRB Detected by HETE
  12. GCN and HETE status
  13. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  14. GRB 010222 - WHT BVRI images
  15. SGR1900+14 burst seen by HETE: BeppoSAX data
  16. GRB 010629 Optical Observations
  17. SGR1900+14: High Fluence Burst Localized by HETE
  18. GRB010629, optical observations
  19. GRB010629: A Burst Localized by HETE
  20. SGR1900+14: Second Burst Localized by HETE
  21. SGR1900+14: A Burst Localized by HETE
  22. SGR1806-20: A Second, Intense Burst Localized by HETE
  23. SGR1806-20: Localization by HETE
  24. HETE Fully-Automated GCN Notices
  25. GRB000301C: Late-time HST/STIS observation
  26. GRB010518: a faint BeppoSAX detection
  27. GRB000418: HST/STIS Second-epoch Observations
  28. X-ray precursors to the large flare from SGR 1900+14
  29. GRB010427, Gamma Ray Observations
  30. SGR 1900+14: No evidence of extended X-ray emission
  31. SGR 1900+14 : RXTE observations
  32. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  33. SGR 1900+14: Correction to GCN 1049
  34. GRB 010222 /corrections to VBT data
  35. Millimeter observation of SGR 1900+14
  36. SGR 1900+14: Detection of extended X-ray emission
  37. SGR 1900+14, Chandra observations
  38. SGR1900+14, I-band observations
  39. GRB010412, field photometry
  40. Giant flare from SGR1900+14
  41. GRB 010326b Optical Observations
  42. GRB010412: BeppoSAX GRBM and WFC observations
  43. GRB010324, revised field photometry
  44. REVISED LOCATION OF GRB010326A
  45. GRB 980326: Late-time HST/STIS observations
  46. GRB010324, field photometry
  47. GRB010326B, field photometry
  48. GRB010326, field photometry
  49. GRB010220, field photometry
  50. Further Optical Observations of GRB 010324
  51. GRB010222, CXO X-ray observations
  52. GRB010324, optical observations
  53. GRB010326B: Localization by HETE (2nd GRB for this date)
  54. GRB 010326 optical observations
  55. GRB010326: Refined Localization by HETE
  56. GRB010326: Localization by HETE
  57. Optical Observations of GRB 010324
  58. GRB010222, late-time optical observation
  59. Support extension to the BeppoSAX mission
  60. GRB 010222 - HEGRA GeV/TeV Observations
  61. GRB010222: Chandra X-ray Observatory Observation
  62. GRB010222: Sub-millimeter vanishing act
  63. GRB010222 - Optical observation
  64. GRB 010222, Optical Observations
  65. GRB010222 - Optical observation
  66. GRB 010222: High-Resolution Keck Spectroscopy
  67. GRB 010214, I-band data
  68. GRB 010222
  69. GRB010222 further R-band photometry
  70. GRB010222: R-band data
  71. GRB 010222: Keck Spectroscopy
  72. GRB010214, field photometry
  73. GRB010222, field photometry
  74. GRB010222 further R-band photometry
  75. GRB010222, possible increase of optical decay slope
  76. GRB 010222 Kyoto optical observation
  77. GRB010222 R-BAND OBSERVATION
  78. GRB010214 follow-up from Hanle
  79. GRB 010222: Near-IR Observations
  80. GRB 010222: Optical Observations
  81. GRB010222: Optical decay slope
  82. GRB 010214, Optical Observations
  83. GRB010222, radio observations
  84. GRB010222, optical observations
  85. GRB010222: BeppoSAX/NFI Observations
  86. GRB010214B,Gamma Ray Observations
  87. GRB 010220, simultaneous optical observations
  88. GRB010220: BeppoSAX WFC and GRBM preliminary data
  89. GRB010214, candidate optical afterglow
  90. GRB010214, optical observations
  91. GRB010214: BeppoSAX WFC and GRBM preliminary data
  92. GRB 010214: X-Ray afterglow
  93. GRB 010214 optical observation
  94. GRB010213, Radio Observations
  95. J-Band Observation of GRB 010214.
  96. GRB010213, Near-IR observations
  97. Possible InfraRed Transient of GRB 010214.
  98. GRB 010214, optical observations
  99. GRB010213 detected by HETE
  100. IPN Status Report

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