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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.

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

17213 results found.

  1. GRB020124 BVRI field photometry
  2. SN2002ap (SN/GRB?) optical spectrographic observations
  3. GRB020127 Optical Observations
  4. SN2002ap (SN/GRB?) UBVRI Field Photometry
  5. GRB020127: Chandra Observations and Prospective Counterparts
  6. pre-SN2002ap (SN/GRB?) imaging of M74
  7. GRB020124, optical observations
  8. GRB020127: Optical observations
  9. GRB 020127, I-band observations starting 3.14-hr after the event
  10. GRB010921 Optical Observations
  11. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  12. GRB020124: Optical observations
  13. GRB 020124: Optical observations
  14. GRB020124(=H1896): Localization of a Long GRB by HETE
  15. Possible optical counterpart to a GRB
  16. GRB011212, Optical Observations
  17. GRB011211: BeppoSAX/GRBM data
  18. Optical polarization observations for GRB011211
  19. GRB 011130: Optical Observations of X-ray and Radio Sources
  20. GRB 011212: optical observation at Asiago
  21. GRB 011211: Evidence for an Optical Break
  22. GRB 011212: optical observation at Oslo (relayed)
  23. GRB 011211: Optical Spectroscopy
  24. GRB 011211, Optical Observations
  25. GRB011212, BVRI field photometry
  26. GRB011211, BVRI field photometry
  27. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  28. Fading of the optical source associated of XRF 011211
  29. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  30. GRB011130 (XRF011130) Chandra Observations
  31. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  32. GRB 011130, K band observations
  33. GRB011130 (XRF011130) SDSS PT i-band observations
  34. XRF011130: Infrared Observations
  35. GRB 011121: J-band observations
  36. GRB 011121: NIR observations, host galaxy?
  37. GRB011121: UBRI Observations
  38. GRB 011121 J-Band Astrometry
  39. GRB 011121: Detection of Bright IR Counterpart
  40. GRB011121: possible redshift, continued decay
  41. GRB 011030: TNG K-band observation
  42. XRF011030: J and K band observations
  43. GRB011030, optical observation
  44. XRF011030: Chandra Observations
  45. GRB011030: Z-band observations
  46. GRB 011030 I-band Observation
  47. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  48. GRB 970828: HST Observations of the Host Galaxy
  49. GRB 000131: HST Detection of the Host Galaxy
  50. GRB 970828: HST Observations of the Host Galaxy
  51. GRB011019: Subaru Optical Observations
  52. GRB011030 - further refinement WFC position
  53. GRB011030: radio search
  54. GRB 010921: Possible supernova component
  55. GRB010921, optical observation at early time
  56. GRB 010921, I-band observations
  57. GRB011019, optical observations
  58. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  59. GRB010921: Spectroscopy of the Host Galaxy
  60. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  61. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  62. GRB010928(=H1770): Localization of a Long GRB by HETE
  63. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  64. GRB010921, negative optical observations
  65. GRB010921 field photometry
  66. H1761: A Bright GRB Detected by HETE
  67. GRB000926, Host Galaxy Observations
  68. GRB001109, Host Galaxy Spectroscopic Observations
  69. Probable SGR or Short Duration GRB Detected by HETE
  70. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  71. BeppoSAX/GRBM detection of GRB010728
  72. GRB 010222 - WHT BVRI images
  73. GRB 010629 Optical Observations
  74. SGR1900+14: High Fluence Burst Localized by HETE
  75. GRB010629, optical observations
  76. GRB010629: A Burst Localized by HETE
  77. SGR1900+14: Second Burst Localized by HETE
  78. SGR1900+14: A Burst Localized by HETE
  79. SGR1806-20: A Second, Intense Burst Localized by HETE
  80. SGR1806-20: Localization by HETE
  81. HETE Fully-Automated GCN Notices
  82. GRB000301C: Late-time HST/STIS observation
  83. GRB010518: a faint BeppoSAX detection
  84. GRB000418: HST/STIS Second-epoch Observations
  85. X-ray precursors to the large flare from SGR 1900+14
  86. GRB010427, Gamma Ray Observations
  87. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  88. Millimeter observation of SGR 1900+14
  89. SGR1900+14, I-band observations
  90. GRB010412, field photometry
  91. Giant flare from SGR1900+14
  92. GRB 010326b Optical Observations
  93. GRB010412: BeppoSAX GRBM and WFC observations
  94. GRB010324, revised field photometry
  95. GRB 980326: Late-time HST/STIS observations
  96. GRB010324, field photometry
  97. GRB010326B, field photometry
  98. GRB010326, field photometry
  99. GRB010220, field photometry
  100. Further Optical Observations of GRB 010324

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