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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"

36681 results found.

  1. GRB 011030 I-band Observations
  2. GRB 011030 K-band Observations
  3. GRB010921, optical observations
  4. GRB 011030, WSRT radio observations
  5. GRB011030 - further refinement WFC position
  6. GRB 011030, Radio observations
  7. GRB 011030, R-band observations
  8. BeppoSAX ALERT: Possible X-ray rich GRB011030
  9. GRB 010921: Possible supernova component
  10. GRB011019: NEAT Optical Observations
  11. GRB010921, optical observation at early time
  12. GRB 010921, I-band observations
  13. GRB011019: Optical observations
  14. GRB011019, optical observations
  15. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  16. GRB010921: Spectroscopy of the Host Galaxy
  17. GRB 010921: The afterglow of HETE #1761
  18. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  19. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  20. GRB010923 as seen by BeppoSAX GRBM
  21. GRB010928(=H1770): Localization of a Long GRB by HETE
  22. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  23. GRB010921, negative optical observations
  24. GRB010921 field photometry
  25. GRB010921 Optical Observations
  26. GRB 010921 DPOSS Images Available
  27. IPN triangulation of GRB010921 (=H1761)
  28. H1761: A Bright GRB Detected by HETE
  29. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  30. HETE Trigger #1760 (GRB 010920B?): a new optical source
  31. HETE Trigger #1759 (GRB 010920?) optical observations
  32. GRB001109, Host Galaxy Astrometry
  33. GRB000926, Host Galaxy Observations
  34. GRB001109, Host Galaxy Spectroscopic Observations
  35. Probable SGR or Short Duration GRB Detected by HETE
  36. GRB000926 Host Galaxy Observations
  37. GRB 010222: HST observations -- host galaxy and late-time decay
  38. BeppoSAX/GRBM detection of GRB 010801
  39. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  40. GRB 010222 - WHT BVRI images
  41. GRB 010629 Optical Observations
  42. GRB010629: Optical Observations
  43. GRB010629, optical observations
  44. IPN triangulation of GRB010629
  45. GRB010629: A Burst Localized by HETE
  46. Possible burst from SGR1806-20
  47. IPN detection of SGR1900+14
  48. GRB 00630: Host Galaxy
  49. IPN triangulation of GRB010613
  50. IPN triangulation of GRB010612
  51. HETE Fully-Automated GCN Notices
  52. GRB000301C: Late-time HST/STIS observation
  53. GRB010518: a faint BeppoSAX detection
  54. GRB000418: HST/STIS Second-epoch Observations
  55. GRB010427, Gamma Ray Observations
  56. SGR1900+14
  57. GRB 010222 /corrections to VBT data
  58. Possible precursor to the SGR1900+14 giant burst
  59. IPN Triangulation of the Giant Flare from SGR1900+14
  60. GRB010412, field photometry
  61. GRB 010326b Optical Observations
  62. GRB010412: Optical observations
  63. GRB010412: Optical observations
  64. IPN Triangulation of GRB010412
  65. BeppoSAX GRB: extension of BSAX operations upto April 30, 2002
  66. BeppoSAX GRB ALERT: GRB010412
  67. GRB Observation Report
  68. GRB010324, revised field photometry
  69. REVISED LOCATION OF GRB010326A
  70. GRB 980326: Late-time HST/STIS observations
  71. GRB010324, field photometry
  72. GRB010326B, field photometry
  73. GRB010326, field photometry
  74. GRB010220, field photometry
  75. Further Optical Observations of GRB 010324
  76. GRB 010326A: Further optical observations
  77. GRB010324: BeppoSAX/GRBM data
  78. GRB 010326B: Optical observations
  79. GRB010324, optical observations
  80. GRB010326B: Localization by HETE (2nd GRB for this date)
  81. GRB 010326: Optical observations
  82. GRB 010326 optical observations
  83. GRB010326: Refined Localization by HETE
  84. GRB010326: Localization by HETE
  85. Duration, ECT, peak flux and fluence of GRB010324
  86. Optical Observations of GRB 010324
  87. IPN TRIANGULATION OF GRB010324
  88. GRB990705, VLT-FORS1 observations of the host galaxy
  89. GRB010222, late-time optical observation
  90. Support extension to the BeppoSAX mission
  91. GRB 010222 - HEGRA GeV/TeV Observations
  92. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  93. GRB010222: Chandra X-ray Observatory Observation
  94. GRB010222: Sub-millimeter vanishing act
  95. GRB 010222, Optical Observations
  96. GRB 010222: High-Resolution Keck Spectroscopy
  97. GRB 010214, I-band data
  98. Sub-millimeter Excess/GRB 010222
  99. GRB 010222
  100. GRB 010222 HST/Chandra TOO

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