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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').
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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

45442 results found.

  1. Correction: GCN1157 (GRB 011121)
  2. GRB011121: UBRI Observations
  3. GRB011121
  4. GRB 011121: Radio Observations
  5. GRB 011121 J-Band Astrometry
  6. GRB011121: continued decay
  7. GRB 011121: Detection of Bright IR Counterpart
  8. GRB011121: possible redshift, continued decay
  9. GRB011121: fading behavior
  10. GRB011121: possible optical counterpart
  11. IPN triangulation of GRB011121
  12. BEPPOSAX GRB011121
  13. GRB 011030: TNG K-band observation
  14. XRF011030: J and K band observations
  15. GRB011030, optical observation
  16. XRF011030: Chandra Observations
  17. GRB 011030: K-band observations
  18. GRB011030: Z-band observations
  19. GRB 011030 R band observations
  20. GRB 011030 I-band Observation
  21. The X-ray Flash 011030 ('GRB 011030')
  22. Non-triggered burst 011030 ("GRB 011030")
  23. The Radio Afterglow from the X-ray Rich GRB 011030
  24. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  25. GRB 970828: HST Observations of the Host Galaxy
  26. GRB 000131: HST Detection of the Host Galaxy
  27. GRB 970828: HST Observations of the Host Galaxy
  28. GRB010921, optical observation
  29. GRB 011019 optical observation
  30. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  31. GRB011019: Subaru Optical Observations
  32. GRB 011030 I-band Observations
  33. GRB 011030 K-band Observations
  34. GRB010921, optical observations
  35. GRB 011030, WSRT radio observations
  36. GRB011030 - further refinement WFC position
  37. GRB 011030, Radio observations
  38. GRB011030: radio search
  39. GRB 011030, R-band observations
  40. X-ray rich GRB011030: BeppoSAX refined positions
  41. BeppoSAX ALERT: Possible X-ray rich GRB011030
  42. GRB 010921: Possible supernova component
  43. GRB011019: NEAT Optical Observations
  44. GRB011019: ROTSE-III optical observations
  45. GRB010921, optical observation at early time
  46. GRB 010921, I-band observations
  47. GRB011019: Optical observations
  48. GRB011019, optical observations
  49. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  50. GRB010921: Spectroscopy of the Host Galaxy
  51. GRB 010921: The afterglow of HETE #1761
  52. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  53. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  54. GRB010923 as seen by BeppoSAX GRBM
  55. GRB010928(=H1770): Localization of a Long GRB by HETE
  56. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  57. GRB010921, negative optical observations
  58. GRB010921 field photometry
  59. GRB010921 Optical Observations
  60. GRB 010921 DPOSS Images Available
  61. IPN triangulation of GRB010921 (=H1761)
  62. H1761: A Bright GRB Detected by HETE
  63. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  64. HETE Trigger #1760 (GRB 010920B?): a new optical source
  65. HETE Trigger #1759 (GRB 010920?) optical observations
  66. GRB001109, Host Galaxy Astrometry
  67. GRB000926, Host Galaxy Observations
  68. GRB001109, Host Galaxy Spectroscopic Observations
  69. Probable SGR or Short Duration GRB Detected by HETE
  70. GRB000926 Host Galaxy Observations
  71. GRB 010222: HST observations -- host galaxy and late-time decay
  72. BeppoSAX/GRBM detection of GRB 010801
  73. GCN and HETE status
  74. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  75. BeppoSAX/GRBM detection of GRB010728
  76. GRB 010222 - WHT BVRI images
  77. SGR1900+14 burst seen by HETE: BeppoSAX data
  78. GRB 010629 Optical Observations
  79. GRB010629: Optical Observations
  80. SGR1900+14: High Fluence Burst Localized by HETE
  81. GRB010629, optical observations
  82. IPN triangulation of GRB010629
  83. GRB010629: A Burst Localized by HETE
  84. SGR1900+14: Second Burst Localized by HETE
  85. SGR1900+14: A Burst Localized by HETE
  86. Possible burst from SGR1806-20
  87. IPN detection of SGR1900+14
  88. SGR1806-20: A Second, Intense Burst Localized by HETE
  89. GRB 00630: Host Galaxy
  90. SGR1806-20: Localization by HETE
  91. IPN triangulation of GRB010613
  92. IPN triangulation of GRB010612
  93. IPN triangulation of GRB010612
  94. HETE Fully-Automated GCN Notices
  95. GRB000301C: Late-time HST/STIS observation
  96. GRB010518: a faint BeppoSAX detection
  97. GRB000418: HST/STIS Second-epoch Observations
  98. X-ray precursors to the large flare from SGR 1900+14
  99. GRB010214, optical observations
  100. GRB010427, Gamma Ray Observations

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