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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"

35253 results found.

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

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