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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"

35259 results found.

  1. GRB010921, negative optical observations
  2. GRB010921 field photometry
  3. GRB010921 Optical Observations
  4. GRB 010921 DPOSS Images Available
  5. IPN triangulation of GRB010921 (=H1761)
  6. H1761: A Bright GRB Detected by HETE
  7. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  8. HETE Trigger #1760 (GRB 010920B?): a new optical source
  9. HETE Trigger #1759 (GRB 010920?) optical observations
  10. GRB001109, Host Galaxy Astrometry
  11. GRB000926, Host Galaxy Observations
  12. GRB001109, Host Galaxy Spectroscopic Observations
  13. Probable SGR or Short Duration GRB Detected by HETE
  14. GRB000926 Host Galaxy Observations
  15. GRB 010222: HST observations -- host galaxy and late-time decay
  16. BeppoSAX/GRBM detection of GRB 010801
  17. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  18. GRB 010222 - WHT BVRI images
  19. GRB 010629 Optical Observations
  20. GRB010629: Optical Observations
  21. GRB010629, optical observations
  22. IPN triangulation of GRB010629
  23. GRB010629: A Burst Localized by HETE
  24. Possible burst from SGR1806-20
  25. IPN detection of SGR1900+14
  26. GRB 00630: Host Galaxy
  27. IPN triangulation of GRB010613
  28. IPN triangulation of GRB010612
  29. HETE Fully-Automated GCN Notices
  30. GRB000301C: Late-time HST/STIS observation
  31. GRB010518: a faint BeppoSAX detection
  32. GRB000418: HST/STIS Second-epoch Observations
  33. GRB010427, Gamma Ray Observations
  34. SGR1900+14
  35. GRB 010222 /corrections to VBT data
  36. Possible precursor to the SGR1900+14 giant burst
  37. IPN Triangulation of the Giant Flare from SGR1900+14
  38. GRB010412, field photometry
  39. GRB 010326b Optical Observations
  40. GRB010412: Optical observations
  41. GRB010412: Optical observations
  42. IPN Triangulation of GRB010412
  43. BeppoSAX GRB: extension of BSAX operations upto April 30, 2002
  44. BeppoSAX GRB ALERT: GRB010412
  45. GRB Observation Report
  46. GRB010324, revised field photometry
  47. REVISED LOCATION OF GRB010326A
  48. GRB 980326: Late-time HST/STIS observations
  49. GRB010324, field photometry
  50. GRB010326B, field photometry
  51. GRB010326, field photometry
  52. GRB010220, field photometry
  53. Further Optical Observations of GRB 010324
  54. GRB 010326A: Further optical observations
  55. GRB010324: BeppoSAX/GRBM data
  56. GRB 010326B: Optical observations
  57. GRB010324, optical observations
  58. GRB010326B: Localization by HETE (2nd GRB for this date)
  59. GRB 010326: Optical observations
  60. GRB 010326 optical observations
  61. GRB010326: Refined Localization by HETE
  62. GRB010326: Localization by HETE
  63. Duration, ECT, peak flux and fluence of GRB010324
  64. Optical Observations of GRB 010324
  65. IPN TRIANGULATION OF GRB010324
  66. GRB990705, VLT-FORS1 observations of the host galaxy
  67. GRB010222, late-time optical observation
  68. Support extension to the BeppoSAX mission
  69. GRB 010222 - HEGRA GeV/TeV Observations
  70. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  71. GRB010222: Chandra X-ray Observatory Observation
  72. GRB010222: Sub-millimeter vanishing act
  73. GRB 010222, Optical Observations
  74. GRB 010222: High-Resolution Keck Spectroscopy
  75. GRB 010214, I-band data
  76. Sub-millimeter Excess/GRB 010222
  77. GRB 010222
  78. GRB 010222 HST/Chandra TOO
  79. GRB 010222
  80. GRB010222 further R-band photometry
  81. GRB010222: R-band data
  82. GRB010222 Optical observations
  83. GRB 010222: Keck Spectroscopy
  84. GRB010214, field photometry
  85. GRB010222, field photometry
  86. GRB010222 further R-band photometry
  87. GRB010222, possible increase of optical decay slope
  88. GRB 010222 Kyoto optical observation
  89. GRB010222: fading behavior
  90. GRB 010222 BV optical observations
  91. GRB 010220: Near-IR Observations
  92. GRB010214 follow-up from Hanle
  93. GRB 010222: Near-IR Observations
  94. GRB 010222: Optical Observations
  95. GRB 010222, Decay Slope Confirmed
  96. GRB010222: Another absorption line system
  97. GRB010222: Optical decay slope
  98. GRB 010214, Optical Observations
  99. GRB010222: Sub-millimeter detection
  100. GRB010222: R-band fading behavior

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