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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"

32508 results found.

  1. GRB011030 - further refinement WFC position
  2. GRB 011030, Radio observations
  3. GRB011030: radio search
  4. GRB 011030, R-band observations
  5. BeppoSAX ALERT: Possible X-ray rich GRB011030
  6. GRB 010921: Possible supernova component
  7. GRB011019: ROTSE-III optical observations
  8. GRB 010921, I-band observations
  9. GRB011019: Optical observations
  10. GRB011019, optical observations -- correction
  11. GRB011019, optical observations
  12. GRB010921: Spectroscopy of the Host Galaxy
  13. GRB 010921: The afterglow of HETE #1761
  14. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  15. GRB010923 as seen by BeppoSAX GRBM
  16. GRB010928(=H1770): Localization of a Long GRB by HETE
  17. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  18. GRB010921, negative optical observations
  19. GRB010921 field photometry
  20. GRB 010921 DPOSS Images Available
  21. IPN triangulation of GRB010921 (=H1761)
  22. H1761: A Bright GRB Detected by HETE
  23. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  24. GRB001109, Host Galaxy Astrometry
  25. GRB000926, Host Galaxy Observations
  26. GRB001109, Host Galaxy Spectroscopic Observations
  27. Probable SGR or Short Duration GRB Detected by HETE
  28. GCN and HETE status
  29. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  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. SGR1900+14: Second Burst Localized by HETE
  38. SGR1900+14: A Burst Localized by HETE
  39. Possible burst from SGR1806-20
  40. SGR1806-20: A Second, Intense Burst Localized by HETE
  41. IPN triangulation of GRB010613
  42. IPN triangulation of GRB010612
  43. IPN triangulation of GRB010612
  44. HETE Fully-Automated GCN Notices
  45. GRB000301C: Late-time HST/STIS observation
  46. GRB000418: HST/STIS Second-epoch Observations
  47. X-ray precursors to the large flare from SGR 1900+14
  48. GRB010214, optical observations
  49. SGR 1900+14: No evidence of extended X-ray emission
  50. SGR 1900+14 : RXTE observations
  51. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  52. SGR1900+14 - correction
  53. SGR1900+14
  54. SGR 1900+14: Correction to GCN 1049
  55. Millimeter observation of SGR 1900+14
  56. SGR 1900+14: Detection of extended X-ray emission
  57. Chandra Observations of SGR 1900+14
  58. SGR 1900+14, Chandra observations
  59. Chandra Observations of SGR 1900+14
  60. Possible precursor to the SGR1900+14 giant burst
  61. SGR1900+14, I-band observations
  62. IPN Triangulation of the Giant Flare from SGR1900+14
  63. GRB 010326b Optical Observations
  64. GRB010412: Optical observations
  65. GRB010412: Optical observations
  66. IPN Triangulation of GRB010412
  67. GRB Observation Report
  68. REVISED LOCATION OF GRB010326A
  69. GRB 980326: Late-time HST/STIS observations
  70. GRB010324, field photometry
  71. GRB010326B, field photometry
  72. GRB010326, field photometry
  73. GRB010220, field photometry
  74. Further Optical Observations of GRB 010324
  75. GRB010222, CXO X-ray observations
  76. GRB010324: BeppoSAX/GRBM data
  77. GRB010324, optical observations
  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. GRB 010222 - HEGRA GeV/TeV Observations
  84. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  85. GRB010222: Chandra X-ray Observatory Observation
  86. GRB010222: Sub-millimeter vanishing act
  87. GRB010222 - Optical observation
  88. GRB 010222, Optical Observations
  89. GRB010220 optical obsercations
  90. GRB010222 - Optical observation
  91. GRB 010222: High-Resolution Keck Spectroscopy
  92. GRB010222: Optical observation and decay
  93. GRB 010214, I-band data
  94. Sub-millimeter Excess/GRB 010222
  95. GRB 010222
  96. GRB 010222 HST/Chandra TOO
  97. GRB010222 further R-band photometry
  98. GRB010222: R-band data
  99. GRB010222 Optical observations
  100. GRB 010222: Keck Spectroscopy

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