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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"

35274 results found.

  1. BeppoSAX ALERT: Possible X-ray rich GRB011030
  2. GRB 010921: Possible supernova component
  3. GRB011019: NEAT Optical Observations
  4. GRB010921, optical observation at early time
  5. GRB 010921, I-band observations
  6. GRB011019: Optical observations
  7. GRB011019, optical observations
  8. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  9. GRB010921: Spectroscopy of the Host Galaxy
  10. GRB 010921: The afterglow of HETE #1761
  11. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  12. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  13. GRB010923 as seen by BeppoSAX GRBM
  14. GRB010928(=H1770): Localization of a Long GRB by HETE
  15. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  16. GRB010921, negative optical observations
  17. GRB010921 field photometry
  18. GRB010921 Optical Observations
  19. GRB 010921 DPOSS Images Available
  20. IPN triangulation of GRB010921 (=H1761)
  21. H1761: A Bright GRB Detected by HETE
  22. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  23. HETE Trigger #1760 (GRB 010920B?): a new optical source
  24. HETE Trigger #1759 (GRB 010920?) optical observations
  25. GRB001109, Host Galaxy Astrometry
  26. GRB000926, Host Galaxy Observations
  27. GRB001109, Host Galaxy Spectroscopic Observations
  28. Probable SGR or Short Duration GRB Detected by HETE
  29. GRB000926 Host Galaxy Observations
  30. GRB 010222: HST observations -- host galaxy and late-time decay
  31. BeppoSAX/GRBM detection of GRB 010801
  32. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  33. GRB 010222 - WHT BVRI images
  34. GRB 010629 Optical Observations
  35. GRB010629: Optical Observations
  36. GRB010629, optical observations
  37. IPN triangulation of GRB010629
  38. GRB010629: A Burst Localized by HETE
  39. Possible burst from SGR1806-20
  40. IPN detection of SGR1900+14
  41. GRB 00630: Host Galaxy
  42. IPN triangulation of GRB010613
  43. IPN triangulation of GRB010612
  44. HETE Fully-Automated GCN Notices
  45. GRB000301C: Late-time HST/STIS observation
  46. GRB010518: a faint BeppoSAX detection
  47. GRB000418: HST/STIS Second-epoch Observations
  48. GRB010427, Gamma Ray Observations
  49. SGR1900+14
  50. GRB 010222 /corrections to VBT data
  51. Possible precursor to the SGR1900+14 giant burst
  52. IPN Triangulation of the Giant Flare from SGR1900+14
  53. GRB010412, field photometry
  54. GRB 010326b Optical Observations
  55. GRB010412: Optical observations
  56. GRB010412: Optical observations
  57. IPN Triangulation of GRB010412
  58. BeppoSAX GRB: extension of BSAX operations upto April 30, 2002
  59. BeppoSAX GRB ALERT: GRB010412
  60. GRB Observation Report
  61. GRB010324, revised field photometry
  62. REVISED LOCATION OF GRB010326A
  63. GRB 980326: Late-time HST/STIS observations
  64. GRB010324, field photometry
  65. GRB010326B, field photometry
  66. GRB010326, field photometry
  67. GRB010220, field photometry
  68. Further Optical Observations of GRB 010324
  69. GRB 010326A: Further optical observations
  70. GRB010324: BeppoSAX/GRBM data
  71. GRB 010326B: Optical observations
  72. GRB010324, optical observations
  73. GRB010326B: Localization by HETE (2nd GRB for this date)
  74. GRB 010326: Optical observations
  75. GRB 010326 optical observations
  76. GRB010326: Refined Localization by HETE
  77. GRB010326: Localization by HETE
  78. Duration, ECT, peak flux and fluence of GRB010324
  79. Optical Observations of GRB 010324
  80. IPN TRIANGULATION OF GRB010324
  81. GRB990705, VLT-FORS1 observations of the host galaxy
  82. GRB010222, late-time optical observation
  83. Support extension to the BeppoSAX mission
  84. GRB 010222 - HEGRA GeV/TeV Observations
  85. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  86. GRB010222: Chandra X-ray Observatory Observation
  87. GRB010222: Sub-millimeter vanishing act
  88. GRB 010222, Optical Observations
  89. GRB 010222: High-Resolution Keck Spectroscopy
  90. GRB 010214, I-band data
  91. Sub-millimeter Excess/GRB 010222
  92. GRB 010222
  93. GRB 010222 HST/Chandra TOO
  94. GRB 010222
  95. GRB010222 further R-band photometry
  96. GRB010222: R-band data
  97. GRB010222 Optical observations
  98. GRB 010222: Keck Spectroscopy
  99. GRB010214, field photometry
  100. GRB010222, field photometry

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