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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"

36154 results found.

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

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