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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').
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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"

36180 results found.

  1. GRB 011030, Radio observations
  2. GRB 011030, R-band observations
  3. BeppoSAX ALERT: Possible X-ray rich GRB011030
  4. GRB 010921: Possible supernova component
  5. GRB011019: NEAT Optical Observations
  6. GRB010921, optical observation at early time
  7. GRB 010921, I-band observations
  8. GRB011019: Optical observations
  9. GRB011019, optical observations
  10. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  11. GRB010921: Spectroscopy of the Host Galaxy
  12. GRB 010921: The afterglow of HETE #1761
  13. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  14. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  15. GRB010923 as seen by BeppoSAX GRBM
  16. GRB010928(=H1770): Localization of a Long GRB by HETE
  17. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  18. GRB010921, negative optical observations
  19. GRB010921 field photometry
  20. GRB010921 Optical Observations
  21. GRB 010921 DPOSS Images Available
  22. IPN triangulation of GRB010921 (=H1761)
  23. H1761: A Bright GRB Detected by HETE
  24. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  25. HETE Trigger #1760 (GRB 010920B?): a new optical source
  26. HETE Trigger #1759 (GRB 010920?) optical observations
  27. GRB001109, Host Galaxy Astrometry
  28. GRB000926, Host Galaxy Observations
  29. GRB001109, Host Galaxy Spectroscopic Observations
  30. Probable SGR or Short Duration GRB Detected by HETE
  31. GRB000926 Host Galaxy Observations
  32. GRB 010222: HST observations -- host galaxy and late-time decay
  33. BeppoSAX/GRBM detection of GRB 010801
  34. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  35. GRB 010222 - WHT BVRI images
  36. GRB 010629 Optical Observations
  37. GRB010629: Optical Observations
  38. GRB010629, optical observations
  39. IPN triangulation of GRB010629
  40. GRB010629: A Burst Localized by HETE
  41. Possible burst from SGR1806-20
  42. IPN detection of SGR1900+14
  43. GRB 00630: Host Galaxy
  44. IPN triangulation of GRB010613
  45. IPN triangulation of GRB010612
  46. HETE Fully-Automated GCN Notices
  47. GRB000301C: Late-time HST/STIS observation
  48. GRB010518: a faint BeppoSAX detection
  49. GRB000418: HST/STIS Second-epoch Observations
  50. GRB010427, Gamma Ray Observations
  51. SGR1900+14
  52. GRB 010222 /corrections to VBT data
  53. Possible precursor to the SGR1900+14 giant burst
  54. IPN Triangulation of the Giant Flare from SGR1900+14
  55. GRB010412, field photometry
  56. GRB 010326b Optical Observations
  57. GRB010412: Optical observations
  58. GRB010412: Optical observations
  59. IPN Triangulation of GRB010412
  60. BeppoSAX GRB: extension of BSAX operations upto April 30, 2002
  61. BeppoSAX GRB ALERT: GRB010412
  62. GRB Observation Report
  63. GRB010324, revised field photometry
  64. REVISED LOCATION OF GRB010326A
  65. GRB 980326: Late-time HST/STIS observations
  66. GRB010324, field photometry
  67. GRB010326B, field photometry
  68. GRB010326, field photometry
  69. GRB010220, field photometry
  70. Further Optical Observations of GRB 010324
  71. GRB 010326A: Further optical observations
  72. GRB010324: BeppoSAX/GRBM data
  73. GRB 010326B: Optical observations
  74. GRB010324, optical observations
  75. GRB010326B: Localization by HETE (2nd GRB for this date)
  76. GRB 010326: Optical observations
  77. GRB 010326 optical observations
  78. GRB010326: Refined Localization by HETE
  79. GRB010326: Localization by HETE
  80. Duration, ECT, peak flux and fluence of GRB010324
  81. Optical Observations of GRB 010324
  82. IPN TRIANGULATION OF GRB010324
  83. GRB990705, VLT-FORS1 observations of the host galaxy
  84. GRB010222, late-time optical observation
  85. Support extension to the BeppoSAX mission
  86. GRB 010222 - HEGRA GeV/TeV Observations
  87. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  88. GRB010222: Chandra X-ray Observatory Observation
  89. GRB010222: Sub-millimeter vanishing act
  90. GRB 010222, Optical Observations
  91. GRB 010222: High-Resolution Keck Spectroscopy
  92. GRB 010214, I-band data
  93. Sub-millimeter Excess/GRB 010222
  94. GRB 010222
  95. GRB 010222 HST/Chandra TOO
  96. GRB 010222
  97. GRB010222 further R-band photometry
  98. GRB010222: R-band data
  99. GRB010222 Optical observations
  100. GRB 010222: Keck Spectroscopy

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