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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"

32492 results found.

  1. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  2. GRB010921, negative optical observations
  3. GRB010921 field photometry
  4. GRB 010921 DPOSS Images Available
  5. IPN triangulation of GRB010921 (=H1761)
  6. H1761: A Bright GRB Detected by HETE
  7. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  8. GRB001109, Host Galaxy Astrometry
  9. GRB000926, Host Galaxy Observations
  10. GRB001109, Host Galaxy Spectroscopic Observations
  11. Probable SGR or Short Duration GRB Detected by HETE
  12. GCN and HETE status
  13. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  14. GRB 010222 - WHT BVRI images
  15. SGR1900+14 burst seen by HETE: BeppoSAX data
  16. GRB 010629 Optical Observations
  17. GRB010629: Optical Observations
  18. SGR1900+14: High Fluence Burst Localized by HETE
  19. GRB010629, optical observations
  20. IPN triangulation of GRB010629
  21. SGR1900+14: Second Burst Localized by HETE
  22. SGR1900+14: A Burst Localized by HETE
  23. Possible burst from SGR1806-20
  24. SGR1806-20: A Second, Intense Burst Localized by HETE
  25. IPN triangulation of GRB010613
  26. IPN triangulation of GRB010612
  27. IPN triangulation of GRB010612
  28. HETE Fully-Automated GCN Notices
  29. GRB000301C: Late-time HST/STIS observation
  30. GRB000418: HST/STIS Second-epoch Observations
  31. X-ray precursors to the large flare from SGR 1900+14
  32. GRB010214, optical observations
  33. SGR 1900+14: No evidence of extended X-ray emission
  34. SGR 1900+14 : RXTE observations
  35. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  36. SGR1900+14 - correction
  37. SGR1900+14
  38. SGR 1900+14: Correction to GCN 1049
  39. Millimeter observation of SGR 1900+14
  40. SGR 1900+14: Detection of extended X-ray emission
  41. Chandra Observations of SGR 1900+14
  42. SGR 1900+14, Chandra observations
  43. Chandra Observations of SGR 1900+14
  44. Possible precursor to the SGR1900+14 giant burst
  45. SGR1900+14, I-band observations
  46. IPN Triangulation of the Giant Flare from SGR1900+14
  47. GRB 010326b Optical Observations
  48. GRB010412: Optical observations
  49. GRB010412: Optical observations
  50. IPN Triangulation of GRB010412
  51. GRB Observation Report
  52. REVISED LOCATION OF GRB010326A
  53. GRB 980326: Late-time HST/STIS observations
  54. GRB010324, field photometry
  55. GRB010326B, field photometry
  56. GRB010326, field photometry
  57. GRB010220, field photometry
  58. Further Optical Observations of GRB 010324
  59. GRB010222, CXO X-ray observations
  60. GRB010324: BeppoSAX/GRBM data
  61. GRB010324, optical observations
  62. Duration, ECT, peak flux and fluence of GRB010324
  63. Optical Observations of GRB 010324
  64. IPN TRIANGULATION OF GRB010324
  65. GRB990705, VLT-FORS1 observations of the host galaxy
  66. GRB010222, late-time optical observation
  67. GRB 010222 - HEGRA GeV/TeV Observations
  68. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  69. GRB010222: Chandra X-ray Observatory Observation
  70. GRB010222: Sub-millimeter vanishing act
  71. GRB010222 - Optical observation
  72. GRB 010222, Optical Observations
  73. GRB010220 optical obsercations
  74. GRB010222 - Optical observation
  75. GRB 010222: High-Resolution Keck Spectroscopy
  76. GRB010222: Optical observation and decay
  77. GRB 010214, I-band data
  78. Sub-millimeter Excess/GRB 010222
  79. GRB 010222
  80. GRB 010222 HST/Chandra TOO
  81. GRB010222 further R-band photometry
  82. GRB010222: R-band data
  83. GRB010222 Optical observations
  84. GRB 010222: Keck Spectroscopy
  85. GRB010222 further R-band photometry
  86. GRB010222, possible increase of optical decay slope
  87. GRB010222: fading behavior
  88. GRB 010222 BV optical observations
  89. GRB010222 R-BAND OBSERVATION
  90. GRB 010220: Near-IR Observations
  91. GRB010214 follow-up from Hanle
  92. GRB 010222: Near-IR Observations
  93. GRB 010222: Optical Observations
  94. GRB 010222, Decay Slope Confirmed
  95. GRB010222: Another absorption line system
  96. GRB010222: Optical decay slope
  97. GRB 010214, Optical Observations
  98. GRB010222: Sub-millimeter detection
  99. GRB010222: R-band fading behavior
  100. GRB010222: Optical Observations

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