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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"

32509 results found.

  1. GRB 011030, WSRT radio observations
  2. GRB011030 - further refinement WFC position
  3. GRB 011030, Radio observations
  4. GRB011030: radio search
  5. GRB 011030, R-band observations
  6. BeppoSAX ALERT: Possible X-ray rich GRB011030
  7. GRB 010921: Possible supernova component
  8. GRB011019: ROTSE-III optical observations
  9. GRB 010921, I-band observations
  10. GRB011019: Optical observations
  11. GRB011019, optical observations -- correction
  12. GRB011019, optical observations
  13. GRB010921: Spectroscopy of the Host Galaxy
  14. GRB 010921: The afterglow of HETE #1761
  15. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  16. GRB010923 as seen by BeppoSAX GRBM
  17. GRB010928(=H1770): Localization of a Long GRB by HETE
  18. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  19. GRB010921, negative optical observations
  20. GRB010921 field photometry
  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. 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. GCN and HETE status
  30. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  31. GRB 010222 - WHT BVRI images
  32. SGR1900+14 burst seen by HETE: BeppoSAX data
  33. GRB 010629 Optical Observations
  34. GRB010629: Optical Observations
  35. SGR1900+14: High Fluence Burst Localized by HETE
  36. GRB010629, optical observations
  37. IPN triangulation of GRB010629
  38. SGR1900+14: Second Burst Localized by HETE
  39. SGR1900+14: A Burst Localized by HETE
  40. Possible burst from SGR1806-20
  41. SGR1806-20: A Second, Intense Burst Localized by HETE
  42. IPN triangulation of GRB010613
  43. IPN triangulation of GRB010612
  44. IPN triangulation of GRB010612
  45. HETE Fully-Automated GCN Notices
  46. GRB000301C: Late-time HST/STIS observation
  47. GRB000418: HST/STIS Second-epoch Observations
  48. X-ray precursors to the large flare from SGR 1900+14
  49. GRB010214, optical observations
  50. SGR 1900+14: No evidence of extended X-ray emission
  51. SGR 1900+14 : RXTE observations
  52. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  53. SGR1900+14 - correction
  54. SGR1900+14
  55. SGR 1900+14: Correction to GCN 1049
  56. Millimeter observation of SGR 1900+14
  57. SGR 1900+14: Detection of extended X-ray emission
  58. Chandra Observations of SGR 1900+14
  59. SGR 1900+14, Chandra observations
  60. Chandra Observations of SGR 1900+14
  61. Possible precursor to the SGR1900+14 giant burst
  62. SGR1900+14, I-band observations
  63. IPN Triangulation of the Giant Flare from SGR1900+14
  64. GRB 010326b Optical Observations
  65. GRB010412: Optical observations
  66. GRB010412: Optical observations
  67. IPN Triangulation of GRB010412
  68. GRB Observation Report
  69. REVISED LOCATION OF GRB010326A
  70. GRB 980326: Late-time HST/STIS observations
  71. GRB010324, field photometry
  72. GRB010326B, field photometry
  73. GRB010326, field photometry
  74. GRB010220, field photometry
  75. Further Optical Observations of GRB 010324
  76. GRB010222, CXO X-ray observations
  77. GRB010324: BeppoSAX/GRBM data
  78. GRB010324, optical observations
  79. Duration, ECT, peak flux and fluence of GRB010324
  80. Optical Observations of GRB 010324
  81. IPN TRIANGULATION OF GRB010324
  82. GRB990705, VLT-FORS1 observations of the host galaxy
  83. GRB010222, late-time optical observation
  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. GRB010222 - Optical observation
  89. GRB 010222, Optical Observations
  90. GRB010220 optical obsercations
  91. GRB010222 - Optical observation
  92. GRB 010222: High-Resolution Keck Spectroscopy
  93. GRB010222: Optical observation and decay
  94. GRB 010214, I-band data
  95. Sub-millimeter Excess/GRB 010222
  96. GRB 010222
  97. GRB 010222 HST/Chandra TOO
  98. GRB010222 further R-band photometry
  99. GRB010222: R-band data
  100. GRB010222 Optical observations

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