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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"

37787 results found.

  1. GRB 970828: HST Observations of the Host Galaxy
  2. GRB 000131: HST Detection of the Host Galaxy
  3. GRB 970828: HST Observations of the Host Galaxy
  4. GRB010921, optical observation
  5. GRB 011019 optical observation
  6. GRB011019: Subaru Optical Observations
  7. GRB 011030 I-band Observations
  8. GRB 011030 K-band Observations
  9. GRB010921, optical observations
  10. GRB 011030, WSRT radio observations
  11. GRB011030 - further refinement WFC position
  12. GRB 011030, Radio observations
  13. GRB 011030, R-band observations
  14. BeppoSAX ALERT: Possible X-ray rich GRB011030
  15. GRB 010921: Possible supernova component
  16. GRB011019: NEAT Optical Observations
  17. GRB010921, optical observation at early time
  18. GRB 010921, I-band observations
  19. GRB011019: Optical observations
  20. GRB011019, optical observations
  21. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  22. GRB010921: Spectroscopy of the Host Galaxy
  23. GRB 010921: The afterglow of HETE #1761
  24. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  25. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  26. GRB010923 as seen by BeppoSAX GRBM
  27. GRB010928(=H1770): Localization of a Long GRB by HETE
  28. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  29. GRB010921, negative optical observations
  30. GRB010921 field photometry
  31. GRB010921 Optical Observations
  32. GRB 010921 DPOSS Images Available
  33. IPN triangulation of GRB010921 (=H1761)
  34. H1761: A Bright GRB Detected by HETE
  35. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  36. HETE Trigger #1760 (GRB 010920B?): a new optical source
  37. HETE Trigger #1759 (GRB 010920?) optical observations
  38. GRB001109, Host Galaxy Astrometry
  39. GRB000926, Host Galaxy Observations
  40. GRB001109, Host Galaxy Spectroscopic Observations
  41. Probable SGR or Short Duration GRB Detected by HETE
  42. GRB000926 Host Galaxy Observations
  43. GRB 010222: HST observations -- host galaxy and late-time decay
  44. BeppoSAX/GRBM detection of GRB 010801
  45. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  46. GRB 010222 - WHT BVRI images
  47. GRB 010629 Optical Observations
  48. GRB010629: Optical Observations
  49. GRB010629, optical observations
  50. IPN triangulation of GRB010629
  51. GRB010629: A Burst Localized by HETE
  52. Possible burst from SGR1806-20
  53. IPN detection of SGR1900+14
  54. GRB 00630: Host Galaxy
  55. IPN triangulation of GRB010613
  56. IPN triangulation of GRB010612
  57. HETE Fully-Automated GCN Notices
  58. GRB000301C: Late-time HST/STIS observation
  59. GRB010518: a faint BeppoSAX detection
  60. GRB000418: HST/STIS Second-epoch Observations
  61. GRB010427, Gamma Ray Observations
  62. SGR1900+14
  63. GRB 010222 /corrections to VBT data
  64. Possible precursor to the SGR1900+14 giant burst
  65. IPN Triangulation of the Giant Flare from SGR1900+14
  66. GRB010412, field photometry
  67. GRB 010326b Optical Observations
  68. GRB010412: Optical observations
  69. GRB010412: Optical observations
  70. IPN Triangulation of GRB010412
  71. BeppoSAX GRB: extension of BSAX operations upto April 30, 2002
  72. BeppoSAX GRB ALERT: GRB010412
  73. GRB Observation Report
  74. GRB010324, revised field photometry
  75. REVISED LOCATION OF GRB010326A
  76. GRB 980326: Late-time HST/STIS observations
  77. GRB010324, field photometry
  78. GRB010326B, field photometry
  79. GRB010326, field photometry
  80. GRB010220, field photometry
  81. Further Optical Observations of GRB 010324
  82. GRB 010326A: Further optical observations
  83. GRB010324: BeppoSAX/GRBM data
  84. GRB 010326B: Optical observations
  85. GRB010324, optical observations
  86. GRB010326B: Localization by HETE (2nd GRB for this date)
  87. GRB 010326: Optical observations
  88. GRB 010326 optical observations
  89. GRB010326: Refined Localization by HETE
  90. GRB010326: Localization by HETE
  91. Duration, ECT, peak flux and fluence of GRB010324
  92. Optical Observations of GRB 010324
  93. IPN TRIANGULATION OF GRB010324
  94. GRB990705, VLT-FORS1 observations of the host galaxy
  95. GRB010222, late-time optical observation
  96. Support extension to the BeppoSAX mission
  97. GRB 010222 - HEGRA GeV/TeV Observations
  98. Congratulate Scott on the 1000th GRB Coordinates Network Circular!
  99. GRB010222: Chandra X-ray Observatory Observation
  100. GRB010222: Sub-millimeter vanishing act

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