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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"

25801 results found.

  1. The X-ray Flash 011030 ('GRB 011030')
  2. Non-triggered burst 011030 ("GRB 011030")
  3. The Radio Afterglow from the X-ray Rich GRB 011030
  4. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  5. GRB 970828: HST Observations of the Host Galaxy
  6. GRB 000131: HST Detection of the Host Galaxy
  7. GRB 970828: HST Observations of the Host Galaxy
  8. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  9. GRB011019: Subaru Optical Observations
  10. GRB 011030 I-band Observations
  11. GRB 011030 K-band Observations
  12. GRB010921, optical observations
  13. GRB011030 - further refinement WFC position
  14. GRB 011030, Radio observations
  15. GRB011030: radio search
  16. GRB 010921: Possible supernova component
  17. GRB010921, optical observation at early time
  18. GRB 010921, I-band observations
  19. GRB011019, optical observations
  20. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  21. GRB 010921: The afterglow of HETE #1761
  22. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  23. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  24. GRB010923 as seen by BeppoSAX GRBM
  25. GRB010928(=H1770): Localization of a Long GRB by HETE
  26. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  27. GRB010921, negative optical observations
  28. GRB010921 field photometry
  29. H1761: A Bright GRB Detected by HETE
  30. GRB000926, Host Galaxy Observations
  31. GRB001109, Host Galaxy Spectroscopic Observations
  32. Probable SGR or Short Duration GRB Detected by HETE
  33. GCN and HETE status
  34. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  35. GRB 010222 - WHT BVRI images
  36. SGR1900+14 burst seen by HETE: BeppoSAX data
  37. GRB 010629 Optical Observations
  38. SGR1900+14: High Fluence Burst Localized by HETE
  39. GRB010629, optical observations
  40. GRB010629: A Burst Localized by HETE
  41. SGR1900+14: Second Burst Localized by HETE
  42. SGR1900+14: A Burst Localized by HETE
  43. SGR1806-20: A Second, Intense Burst Localized by HETE
  44. SGR1806-20: Localization by HETE
  45. HETE Fully-Automated GCN Notices
  46. GRB000301C: Late-time HST/STIS observation
  47. GRB010518: a faint BeppoSAX detection
  48. GRB000418: HST/STIS Second-epoch Observations
  49. X-ray precursors to the large flare from SGR 1900+14
  50. GRB010427, Gamma Ray Observations
  51. SGR 1900+14: No evidence of extended X-ray emission
  52. SGR 1900+14 : RXTE observations
  53. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  54. SGR 1900+14: Correction to GCN 1049
  55. GRB 010222 /corrections to VBT data
  56. Millimeter observation of SGR 1900+14
  57. SGR 1900+14: Detection of extended X-ray emission
  58. SGR 1900+14, Chandra observations
  59. SGR1900+14, I-band observations
  60. GRB010412, field photometry
  61. Giant flare from SGR1900+14
  62. GRB 010326b Optical Observations
  63. GRB010412: BeppoSAX GRBM and WFC observations
  64. GRB010324, revised field photometry
  65. REVISED LOCATION OF GRB010326A
  66. GRB 980326: Late-time HST/STIS observations
  67. GRB010324, field photometry
  68. GRB010326B, field photometry
  69. GRB010326, field photometry
  70. GRB010220, field photometry
  71. Further Optical Observations of GRB 010324
  72. GRB010222, CXO X-ray observations
  73. GRB010324, optical observations
  74. GRB010326B: Localization by HETE (2nd GRB for this date)
  75. GRB 010326 optical observations
  76. GRB010326: Refined Localization by HETE
  77. GRB010326: Localization by HETE
  78. Optical Observations of GRB 010324
  79. GRB010222, late-time optical observation
  80. Support extension to the BeppoSAX mission
  81. GRB 010222 - HEGRA GeV/TeV Observations
  82. GRB010222: Chandra X-ray Observatory Observation
  83. GRB010222: Sub-millimeter vanishing act
  84. GRB010222 - Optical observation
  85. GRB 010222, Optical Observations
  86. GRB010222 - Optical observation
  87. GRB 010222: High-Resolution Keck Spectroscopy
  88. GRB 010214, I-band data
  89. GRB 010222
  90. GRB010222 further R-band photometry
  91. GRB010222: R-band data
  92. GRB 010222: Keck Spectroscopy
  93. GRB010214, field photometry
  94. GRB010222, field photometry
  95. GRB010222 further R-band photometry
  96. GRB010222, possible increase of optical decay slope
  97. GRB 010222 Kyoto optical observation
  98. GRB010222 R-BAND OBSERVATION
  99. GRB010214 follow-up from Hanle
  100. GRB 010222: Near-IR Observations

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