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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"

39170 results found.

  1. H1761: A Bright GRB Detected by HETE
  2. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  3. HETE Trigger #1760 (GRB 010920B?): a new optical source
  4. HETE Trigger #1759 (GRB 010920?) optical observations
  5. GRB001109, Host Galaxy Astrometry
  6. GRB000926, Host Galaxy Observations
  7. GRB001109, Host Galaxy Spectroscopic Observations
  8. Probable SGR or Short Duration GRB Detected by HETE
  9. GRB000926 Host Galaxy Observations
  10. GRB 010222: HST observations -- host galaxy and late-time decay
  11. BeppoSAX/GRBM detection of GRB 010801
  12. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  13. GRB 010222 - WHT BVRI images
  14. GRB 010629 Optical Observations
  15. GRB010629: Optical Observations
  16. GRB010629, optical observations
  17. IPN triangulation of GRB010629
  18. GRB010629: A Burst Localized by HETE
  19. Possible burst from SGR1806-20
  20. IPN detection of SGR1900+14
  21. GRB 00630: Host Galaxy
  22. IPN triangulation of GRB010613
  23. IPN triangulation of GRB010612
  24. HETE Fully-Automated GCN Notices
  25. GRB000301C: Late-time HST/STIS observation
  26. GRB010518: a faint BeppoSAX detection
  27. GRB000418: HST/STIS Second-epoch Observations
  28. GRB010427, Gamma Ray Observations
  29. SGR1900+14
  30. GRB 010222 /corrections to VBT data
  31. Possible precursor to the SGR1900+14 giant burst
  32. IPN Triangulation of the Giant Flare from SGR1900+14
  33. GRB010412, field photometry
  34. GRB 010326b Optical Observations
  35. GRB010412: Optical observations
  36. GRB010412: Optical observations
  37. IPN Triangulation of GRB010412
  38. BeppoSAX GRB: extension of BSAX operations upto April 30, 2002
  39. BeppoSAX GRB ALERT: GRB010412
  40. GRB Observation Report
  41. GRB010324, revised field photometry
  42. REVISED LOCATION OF GRB010326A
  43. GRB 980326: Late-time HST/STIS observations
  44. GRB010324, field photometry
  45. GRB010326B, field photometry
  46. GRB010326, field photometry
  47. GRB010220, field photometry
  48. Further Optical Observations of GRB 010324
  49. GRB 010326A: Further optical observations
  50. GRB010324: BeppoSAX/GRBM data
  51. GRB 010326B: Optical observations
  52. GRB010324, optical observations
  53. GRB010326B: Localization by HETE (2nd GRB for this date)
  54. GRB 010326: Optical observations
  55. GRB 010326 optical observations
  56. GRB010326: Refined Localization by HETE
  57. GRB010326: Localization by HETE
  58. Duration, ECT, peak flux and fluence of GRB010324
  59. Optical Observations of GRB 010324
  60. IPN TRIANGULATION OF GRB010324
  61. GRB990705, VLT-FORS1 observations of the host galaxy
  62. GRB010222, late-time optical observation
  63. Support extension to the BeppoSAX mission
  64. GRB 010222 - HEGRA GeV/TeV Observations
  65. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  66. GRB010222: Chandra X-ray Observatory Observation
  67. GRB010222: Sub-millimeter vanishing act
  68. GRB 010222, Optical Observations
  69. GRB 010222: High-Resolution Keck Spectroscopy
  70. GRB 010214, I-band data
  71. Sub-millimeter Excess/GRB 010222
  72. GRB 010222
  73. GRB 010222 HST/Chandra TOO
  74. GRB 010222
  75. GRB010222 further R-band photometry
  76. GRB010222: R-band data
  77. GRB010222 Optical observations
  78. GRB 010222: Keck Spectroscopy
  79. GRB010214, field photometry
  80. GRB010222, field photometry
  81. GRB010222 further R-band photometry
  82. GRB010222, possible increase of optical decay slope
  83. GRB 010222 Kyoto optical observation
  84. GRB010222: fading behavior
  85. GRB 010222 BV optical observations
  86. GRB 010220: Near-IR Observations
  87. GRB010214 follow-up from Hanle
  88. GRB 010222: Near-IR Observations
  89. GRB 010222: Optical Observations
  90. GRB 010222, Decay Slope Confirmed
  91. GRB010222: Another absorption line system
  92. GRB010222: Optical decay slope
  93. GRB 010214, Optical Observations
  94. GRB010222: Sub-millimeter detection
  95. GRB010222: R-band fading behavior
  96. GRB010222: Optical Observations
  97. GRB010222, optical observations
  98. GRB010222: BeppoSAX/NFI Observations
  99. Redshift of the Optical Transient of GRB010222
  100. GRB010214B,Gamma Ray Observations

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