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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"

32504 results found.

  1. BeppoSAX ALERT: Possible X-ray rich GRB011030
  2. GRB 010921: Possible supernova component
  3. GRB011019: ROTSE-III optical observations
  4. GRB 010921, I-band observations
  5. GRB011019: Optical observations
  6. GRB011019, optical observations -- correction
  7. GRB011019, optical observations
  8. GRB010921: Spectroscopy of the Host Galaxy
  9. GRB 010921: The afterglow of HETE #1761
  10. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  11. GRB010923 as seen by BeppoSAX GRBM
  12. GRB010928(=H1770): Localization of a Long GRB by HETE
  13. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  14. GRB010921, negative optical observations
  15. GRB010921 field photometry
  16. GRB 010921 DPOSS Images Available
  17. IPN triangulation of GRB010921 (=H1761)
  18. H1761: A Bright GRB Detected by HETE
  19. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  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. GCN and HETE status
  25. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  26. GRB 010222 - WHT BVRI images
  27. SGR1900+14 burst seen by HETE: BeppoSAX data
  28. GRB 010629 Optical Observations
  29. GRB010629: Optical Observations
  30. SGR1900+14: High Fluence Burst Localized by HETE
  31. GRB010629, optical observations
  32. IPN triangulation of GRB010629
  33. SGR1900+14: Second Burst Localized by HETE
  34. SGR1900+14: A Burst Localized by HETE
  35. Possible burst from SGR1806-20
  36. SGR1806-20: A Second, Intense Burst Localized by HETE
  37. IPN triangulation of GRB010613
  38. IPN triangulation of GRB010612
  39. IPN triangulation of GRB010612
  40. HETE Fully-Automated GCN Notices
  41. GRB000301C: Late-time HST/STIS observation
  42. GRB000418: HST/STIS Second-epoch Observations
  43. X-ray precursors to the large flare from SGR 1900+14
  44. GRB010214, optical observations
  45. SGR 1900+14: No evidence of extended X-ray emission
  46. SGR 1900+14 : RXTE observations
  47. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  48. SGR1900+14 - correction
  49. SGR1900+14
  50. SGR 1900+14: Correction to GCN 1049
  51. Millimeter observation of SGR 1900+14
  52. SGR 1900+14: Detection of extended X-ray emission
  53. Chandra Observations of SGR 1900+14
  54. SGR 1900+14, Chandra observations
  55. Chandra Observations of SGR 1900+14
  56. Possible precursor to the SGR1900+14 giant burst
  57. SGR1900+14, I-band observations
  58. IPN Triangulation of the Giant Flare from SGR1900+14
  59. GRB 010326b Optical Observations
  60. GRB010412: Optical observations
  61. GRB010412: Optical observations
  62. IPN Triangulation of GRB010412
  63. GRB Observation Report
  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. GRB010222, CXO X-ray observations
  72. GRB010324: BeppoSAX/GRBM data
  73. GRB010324, optical observations
  74. Duration, ECT, peak flux and fluence of GRB010324
  75. Optical Observations of GRB 010324
  76. IPN TRIANGULATION OF GRB010324
  77. GRB990705, VLT-FORS1 observations of the host galaxy
  78. GRB010222, late-time optical observation
  79. GRB 010222 - HEGRA GeV/TeV Observations
  80. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  81. GRB010222: Chandra X-ray Observatory Observation
  82. GRB010222: Sub-millimeter vanishing act
  83. GRB010222 - Optical observation
  84. GRB 010222, Optical Observations
  85. GRB010220 optical obsercations
  86. GRB010222 - Optical observation
  87. GRB 010222: High-Resolution Keck Spectroscopy
  88. GRB010222: Optical observation and decay
  89. GRB 010214, I-band data
  90. Sub-millimeter Excess/GRB 010222
  91. GRB 010222
  92. GRB 010222 HST/Chandra TOO
  93. GRB010222 further R-band photometry
  94. GRB010222: R-band data
  95. GRB010222 Optical observations
  96. GRB 010222: Keck Spectroscopy
  97. GRB010222 further R-band photometry
  98. GRB010222, possible increase of optical decay slope
  99. GRB010222: fading behavior
  100. GRB 010222 BV optical observations

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