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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"

35952 results found.

  1. HETE Trigger #1760 (GRB 010920B?): a new optical source
  2. HETE Trigger #1759 (GRB 010920?) optical observations
  3. GRB001109, Host Galaxy Astrometry
  4. GRB000926, Host Galaxy Observations
  5. GRB001109, Host Galaxy Spectroscopic Observations
  6. Probable SGR or Short Duration GRB Detected by HETE
  7. GRB000926 Host Galaxy Observations
  8. GRB 010222: HST observations -- host galaxy and late-time decay
  9. BeppoSAX/GRBM detection of GRB 010801
  10. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  11. GRB 010222 - WHT BVRI images
  12. GRB 010629 Optical Observations
  13. GRB010629: Optical Observations
  14. GRB010629, optical observations
  15. IPN triangulation of GRB010629
  16. GRB010629: A Burst Localized by HETE
  17. Possible burst from SGR1806-20
  18. IPN detection of SGR1900+14
  19. GRB 00630: Host Galaxy
  20. IPN triangulation of GRB010613
  21. IPN triangulation of GRB010612
  22. HETE Fully-Automated GCN Notices
  23. GRB000301C: Late-time HST/STIS observation
  24. GRB010518: a faint BeppoSAX detection
  25. GRB000418: HST/STIS Second-epoch Observations
  26. GRB010427, Gamma Ray Observations
  27. SGR1900+14
  28. GRB 010222 /corrections to VBT data
  29. Possible precursor to the SGR1900+14 giant burst
  30. IPN Triangulation of the Giant Flare from SGR1900+14
  31. GRB010412, field photometry
  32. GRB 010326b Optical Observations
  33. GRB010412: Optical observations
  34. GRB010412: Optical observations
  35. IPN Triangulation of GRB010412
  36. BeppoSAX GRB: extension of BSAX operations upto April 30, 2002
  37. BeppoSAX GRB ALERT: GRB010412
  38. GRB Observation Report
  39. GRB010324, revised field photometry
  40. REVISED LOCATION OF GRB010326A
  41. GRB 980326: Late-time HST/STIS observations
  42. GRB010324, field photometry
  43. GRB010326B, field photometry
  44. GRB010326, field photometry
  45. GRB010220, field photometry
  46. Further Optical Observations of GRB 010324
  47. GRB 010326A: Further optical observations
  48. GRB010324: BeppoSAX/GRBM data
  49. GRB 010326B: Optical observations
  50. GRB010324, optical observations
  51. GRB010326B: Localization by HETE (2nd GRB for this date)
  52. GRB 010326: Optical observations
  53. GRB 010326 optical observations
  54. GRB010326: Refined Localization by HETE
  55. GRB010326: Localization by HETE
  56. Duration, ECT, peak flux and fluence of GRB010324
  57. Optical Observations of GRB 010324
  58. IPN TRIANGULATION OF GRB010324
  59. GRB990705, VLT-FORS1 observations of the host galaxy
  60. GRB010222, late-time optical observation
  61. Support extension to the BeppoSAX mission
  62. GRB 010222 - HEGRA GeV/TeV Observations
  63. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  64. GRB010222: Chandra X-ray Observatory Observation
  65. GRB010222: Sub-millimeter vanishing act
  66. GRB 010222, Optical Observations
  67. GRB 010222: High-Resolution Keck Spectroscopy
  68. GRB 010214, I-band data
  69. Sub-millimeter Excess/GRB 010222
  70. GRB 010222
  71. GRB 010222 HST/Chandra TOO
  72. GRB 010222
  73. GRB010222 further R-band photometry
  74. GRB010222: R-band data
  75. GRB010222 Optical observations
  76. GRB 010222: Keck Spectroscopy
  77. GRB010214, field photometry
  78. GRB010222, field photometry
  79. GRB010222 further R-band photometry
  80. GRB010222, possible increase of optical decay slope
  81. GRB 010222 Kyoto optical observation
  82. GRB010222: fading behavior
  83. GRB 010222 BV optical observations
  84. GRB 010220: Near-IR Observations
  85. GRB010214 follow-up from Hanle
  86. GRB 010222: Near-IR Observations
  87. GRB 010222: Optical Observations
  88. GRB 010222, Decay Slope Confirmed
  89. GRB010222: Another absorption line system
  90. GRB010222: Optical decay slope
  91. GRB 010214, Optical Observations
  92. GRB010222: Sub-millimeter detection
  93. GRB010222: R-band fading behavior
  94. GRB010222: Optical Observations
  95. GRB010222, optical observations
  96. GRB010222: BeppoSAX/NFI Observations
  97. Redshift of the Optical Transient of GRB010222
  98. GRB010214B,Gamma Ray Observations
  99. GRB010222
  100. ALERT: GRB010222: the brightest GRB observed by BeppoSAX

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