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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"

32510 results found.

  1. GRB010921, optical observations
  2. GRB 011030, WSRT radio observations
  3. GRB011030 - further refinement WFC position
  4. GRB 011030, Radio observations
  5. GRB011030: radio search
  6. GRB 011030, R-band observations
  7. BeppoSAX ALERT: Possible X-ray rich GRB011030
  8. GRB 010921: Possible supernova component
  9. GRB011019: ROTSE-III optical observations
  10. GRB 010921, I-band observations
  11. GRB011019: Optical observations
  12. GRB011019, optical observations -- correction
  13. GRB011019, optical observations
  14. GRB010921: Spectroscopy of the Host Galaxy
  15. GRB 010921: The afterglow of HETE #1761
  16. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  17. GRB010923 as seen by BeppoSAX GRBM
  18. GRB010928(=H1770): Localization of a Long GRB by HETE
  19. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  20. GRB010921, negative optical observations
  21. GRB010921 field photometry
  22. GRB 010921 DPOSS Images Available
  23. IPN triangulation of GRB010921 (=H1761)
  24. H1761: A Bright GRB Detected by HETE
  25. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  26. GRB001109, Host Galaxy Astrometry
  27. GRB000926, Host Galaxy Observations
  28. GRB001109, Host Galaxy Spectroscopic Observations
  29. Probable SGR or Short Duration GRB Detected by HETE
  30. GCN and HETE status
  31. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  32. GRB 010222 - WHT BVRI images
  33. SGR1900+14 burst seen by HETE: BeppoSAX data
  34. GRB 010629 Optical Observations
  35. GRB010629: Optical Observations
  36. SGR1900+14: High Fluence Burst Localized by HETE
  37. GRB010629, optical observations
  38. IPN triangulation of GRB010629
  39. SGR1900+14: Second Burst Localized by HETE
  40. SGR1900+14: A Burst Localized by HETE
  41. Possible burst from SGR1806-20
  42. SGR1806-20: A Second, Intense Burst Localized by HETE
  43. IPN triangulation of GRB010613
  44. IPN triangulation of GRB010612
  45. IPN triangulation of GRB010612
  46. HETE Fully-Automated GCN Notices
  47. GRB000301C: Late-time HST/STIS observation
  48. GRB000418: HST/STIS Second-epoch Observations
  49. X-ray precursors to the large flare from SGR 1900+14
  50. GRB010214, optical 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. SGR1900+14 - correction
  55. SGR1900+14
  56. SGR 1900+14: Correction to GCN 1049
  57. Millimeter observation of SGR 1900+14
  58. SGR 1900+14: Detection of extended X-ray emission
  59. Chandra Observations of SGR 1900+14
  60. SGR 1900+14, Chandra observations
  61. Chandra Observations of SGR 1900+14
  62. Possible precursor to the SGR1900+14 giant burst
  63. SGR1900+14, I-band observations
  64. IPN Triangulation of the Giant Flare from SGR1900+14
  65. GRB 010326b Optical Observations
  66. GRB010412: Optical observations
  67. GRB010412: Optical observations
  68. IPN Triangulation of GRB010412
  69. GRB Observation Report
  70. REVISED LOCATION OF GRB010326A
  71. GRB 980326: Late-time HST/STIS observations
  72. GRB010324, field photometry
  73. GRB010326B, field photometry
  74. GRB010326, field photometry
  75. GRB010220, field photometry
  76. Further Optical Observations of GRB 010324
  77. GRB010222, CXO X-ray observations
  78. GRB010324: BeppoSAX/GRBM data
  79. GRB010324, optical observations
  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. GRB 010222 - HEGRA GeV/TeV Observations
  86. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  87. GRB010222: Chandra X-ray Observatory Observation
  88. GRB010222: Sub-millimeter vanishing act
  89. GRB010222 - Optical observation
  90. GRB 010222, Optical Observations
  91. GRB010220 optical obsercations
  92. GRB010222 - Optical observation
  93. GRB 010222: High-Resolution Keck Spectroscopy
  94. GRB010222: Optical observation and decay
  95. GRB 010214, I-band data
  96. Sub-millimeter Excess/GRB 010222
  97. GRB 010222
  98. GRB 010222 HST/Chandra TOO
  99. GRB010222 further R-band photometry
  100. GRB010222: R-band data

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