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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"

41687 results found.

  1. GRB011019, optical observations -- correction
  2. GRB011019, optical observations
  3. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  4. GRB010921: Spectroscopy of the Host Galaxy
  5. GRB 010921: The afterglow of HETE #1761
  6. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  7. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  8. GRB010923 as seen by BeppoSAX GRBM
  9. GRB010928(=H1770): Localization of a Long GRB by HETE
  10. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  11. GRB010921, negative optical observations
  12. GRB010921 field photometry
  13. GRB010921 Optical Observations
  14. GRB 010921 DPOSS Images Available
  15. IPN triangulation of GRB010921 (=H1761)
  16. H1761: A Bright GRB Detected by HETE
  17. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  18. HETE Trigger #1760 (GRB 010920B?): a new optical source
  19. HETE Trigger #1759 (GRB 010920?) optical observations
  20. GRB001109, Host Galaxy Astrometry
  21. GRB000926, Host Galaxy Observations
  22. GRB001109, Host Galaxy Spectroscopic Observations
  23. Probable SGR or Short Duration GRB Detected by HETE
  24. GRB000926 Host Galaxy Observations
  25. GRB 010222: HST observations -- host galaxy and late-time decay
  26. BeppoSAX/GRBM detection of GRB 010801
  27. GCN and HETE status
  28. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  29. BeppoSAX/GRBM detection of GRB010728
  30. GRB 010222 - WHT BVRI images
  31. SGR1900+14 burst seen by HETE: BeppoSAX data
  32. GRB 010629 Optical Observations
  33. GRB010629: Optical Observations
  34. SGR1900+14: High Fluence Burst Localized by HETE
  35. GRB010629, optical observations
  36. IPN triangulation of GRB010629
  37. GRB010629: A Burst Localized by HETE
  38. SGR1900+14: Second Burst Localized by HETE
  39. SGR1900+14: A Burst Localized by HETE
  40. Possible burst from SGR1806-20
  41. IPN detection of SGR1900+14
  42. SGR1806-20: A Second, Intense Burst Localized by HETE
  43. GRB 00630: Host Galaxy
  44. SGR1806-20: Localization by HETE
  45. IPN triangulation of GRB010613
  46. IPN triangulation of GRB010612
  47. IPN triangulation of GRB010612
  48. HETE Fully-Automated GCN Notices
  49. GRB000301C: Late-time HST/STIS observation
  50. GRB010518: a faint BeppoSAX detection
  51. GRB000418: HST/STIS Second-epoch Observations
  52. X-ray precursors to the large flare from SGR 1900+14
  53. GRB010214, optical observations
  54. GRB010427, Gamma Ray Observations
  55. SGR 1900+14: No evidence of extended X-ray emission
  56. SGR 1900+14 : RXTE observations
  57. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  58. SGR1900+14 - correction
  59. SGR1900+14
  60. SGR 1900+14: Correction to GCN 1049
  61. GRB 010222 /corrections to VBT data
  62. Millimeter observation of SGR 1900+14
  63. SGR 1900+14: Detection of extended X-ray emission
  64. Chandra Observations of SGR 1900+14
  65. SGR 1900+14, Chandra observations
  66. Chandra Observations of SGR 1900+14
  67. Possible precursor to the SGR1900+14 giant burst
  68. SGR1900+14, I-band observations
  69. IPN Triangulation of the Giant Flare from SGR1900+14
  70. GRB010412, field photometry
  71. Giant flare from SGR1900+14
  72. GRB 010326b Optical Observations
  73. GRB010412: Optical observations
  74. GRB010412: Optical observations
  75. GRB010412: BeppoSAX GRBM and WFC observations
  76. IPN Triangulation of GRB010412
  77. GRB Observation Report
  78. GRB010324, revised field photometry
  79. REVISED LOCATION OF GRB010326A
  80. GRB 980326: Late-time HST/STIS observations
  81. GRB010324, field photometry
  82. GRB010326B, field photometry
  83. GRB010326, field photometry
  84. GRB010220, field photometry
  85. Further Optical Observations of GRB 010324
  86. GRB010222, CXO X-ray observations
  87. GRB 010326A: Further optical observations
  88. GRB010324: BeppoSAX/GRBM data
  89. GRB 010326B: Optical observations
  90. GRB010324, optical observations
  91. GRB010326B: Localization by HETE (2nd GRB for this date)
  92. GRB010326: Localization by HETE
  93. Duration, ECT, peak flux and fluence of GRB010324
  94. Optical Observations of GRB 010324
  95. IPN TRIANGULATION OF GRB010324
  96. GRB990705, VLT-FORS1 observations of the host galaxy
  97. GRB010222, late-time optical observation
  98. Support extension to the BeppoSAX mission
  99. GRB 010222 - HEGRA GeV/TeV Observations
  100. Congratulate Scott on the 1000th GRB Coordinates Network Circular!

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