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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"

36053 results found.

  1. GRB000926, Host Galaxy Observations
  2. GRB001109, Host Galaxy Spectroscopic Observations
  3. Probable SGR or Short Duration GRB Detected by HETE
  4. GRB000926 Host Galaxy Observations
  5. GRB 010222: HST observations -- host galaxy and late-time decay
  6. BeppoSAX/GRBM detection of GRB 010801
  7. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  8. GRB 010222 - WHT BVRI images
  9. GRB 010629 Optical Observations
  10. GRB010629: Optical Observations
  11. GRB010629, optical observations
  12. IPN triangulation of GRB010629
  13. GRB010629: A Burst Localized by HETE
  14. Possible burst from SGR1806-20
  15. IPN detection of SGR1900+14
  16. GRB 00630: Host Galaxy
  17. IPN triangulation of GRB010613
  18. IPN triangulation of GRB010612
  19. HETE Fully-Automated GCN Notices
  20. GRB000301C: Late-time HST/STIS observation
  21. GRB010518: a faint BeppoSAX detection
  22. GRB000418: HST/STIS Second-epoch Observations
  23. GRB010427, Gamma Ray Observations
  24. SGR1900+14
  25. GRB 010222 /corrections to VBT data
  26. Possible precursor to the SGR1900+14 giant burst
  27. IPN Triangulation of the Giant Flare from SGR1900+14
  28. GRB010412, field photometry
  29. GRB 010326b Optical Observations
  30. GRB010412: Optical observations
  31. GRB010412: Optical observations
  32. IPN Triangulation of GRB010412
  33. BeppoSAX GRB: extension of BSAX operations upto April 30, 2002
  34. BeppoSAX GRB ALERT: GRB010412
  35. GRB Observation Report
  36. GRB010324, revised field photometry
  37. REVISED LOCATION OF GRB010326A
  38. GRB 980326: Late-time HST/STIS observations
  39. GRB010324, field photometry
  40. GRB010326B, field photometry
  41. GRB010326, field photometry
  42. GRB010220, field photometry
  43. Further Optical Observations of GRB 010324
  44. GRB 010326A: Further optical observations
  45. GRB010324: BeppoSAX/GRBM data
  46. GRB 010326B: Optical observations
  47. GRB010324, optical observations
  48. GRB010326B: Localization by HETE (2nd GRB for this date)
  49. GRB 010326: Optical observations
  50. GRB 010326 optical observations
  51. GRB010326: Refined Localization by HETE
  52. GRB010326: Localization by HETE
  53. Duration, ECT, peak flux and fluence of GRB010324
  54. Optical Observations of GRB 010324
  55. IPN TRIANGULATION OF GRB010324
  56. GRB990705, VLT-FORS1 observations of the host galaxy
  57. GRB010222, late-time optical observation
  58. Support extension to the BeppoSAX mission
  59. GRB 010222 - HEGRA GeV/TeV Observations
  60. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  61. GRB010222: Chandra X-ray Observatory Observation
  62. GRB010222: Sub-millimeter vanishing act
  63. GRB 010222, Optical Observations
  64. GRB 010222: High-Resolution Keck Spectroscopy
  65. GRB 010214, I-band data
  66. Sub-millimeter Excess/GRB 010222
  67. GRB 010222
  68. GRB 010222 HST/Chandra TOO
  69. GRB 010222
  70. GRB010222 further R-band photometry
  71. GRB010222: R-band data
  72. GRB010222 Optical observations
  73. GRB 010222: Keck Spectroscopy
  74. GRB010214, field photometry
  75. GRB010222, field photometry
  76. GRB010222 further R-band photometry
  77. GRB010222, possible increase of optical decay slope
  78. GRB 010222 Kyoto optical observation
  79. GRB010222: fading behavior
  80. GRB 010222 BV optical observations
  81. GRB 010220: Near-IR Observations
  82. GRB010214 follow-up from Hanle
  83. GRB 010222: Near-IR Observations
  84. GRB 010222: Optical Observations
  85. GRB 010222, Decay Slope Confirmed
  86. GRB010222: Another absorption line system
  87. GRB010222: Optical decay slope
  88. GRB 010214, Optical Observations
  89. GRB010222: Sub-millimeter detection
  90. GRB010222: R-band fading behavior
  91. GRB010222: Optical Observations
  92. GRB010222, optical observations
  93. GRB010222: BeppoSAX/NFI Observations
  94. Redshift of the Optical Transient of GRB010222
  95. GRB010214B,Gamma Ray Observations
  96. GRB010222
  97. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  98. GRB 010220, simultaneous optical observations
  99. GRB010220: BeppoSAX WFC and GRBM preliminary data
  100. BeppoSAX ALERT: GRB010220

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