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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"

28036 results found.

  1. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  2. GRB 011130: Optical Observations of X-ray and Radio Sources
  3. GRB 011212: optical observation at Asiago
  4. GRB 011211: Evidence for an Optical Break
  5. GRB 011211: TNG Spectroscopic Observations
  6. optical follow-up of GRB(XRF) 011211
  7. GRB 011212: optical observation at Oslo (relayed)
  8. GRB 011211, Optical Observations
  9. GRB011212, BVRI field photometry
  10. GRB011211, BVRI field photometry
  11. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  12. Fading of the optical source associated of XRF 011211
  13. GRB 011211 Optical Observations: Likely Afterglow
  14. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  15. GRB011130 (XRF011130) Chandra Observations
  16. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  17. GRB 011130, K band observations
  18. GRB011130, optical observations
  19. GRB011130 (=XRF011130): Second Revised Localization by HETE
  20. GRB011130 (XRF011130) SDSS PT i-band observations
  21. XRF011130: Infrared Observations
  22. GRB 011121
  23. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  24. GRB 011121: J-band observations
  25. GRB 011121: NIR observations, host galaxy?
  26. GRB011121: UBRI Observations
  27. GRB 011121 J-Band Astrometry
  28. GRB 011121: Detection of Bright IR Counterpart
  29. GRB011121: possible redshift, continued decay
  30. GRB 011030: TNG K-band observation
  31. XRF011030: J and K band observations
  32. XRF011030: Chandra Observations
  33. GRB011030: Z-band observations
  34. GRB 011030 R band observations
  35. GRB 011030 I-band Observation
  36. The X-ray Flash 011030 ('GRB 011030')
  37. Non-triggered burst 011030 ("GRB 011030")
  38. The Radio Afterglow from the X-ray Rich GRB 011030
  39. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  40. GRB 970828: HST Observations of the Host Galaxy
  41. GRB 000131: HST Detection of the Host Galaxy
  42. GRB 970828: HST Observations of the Host Galaxy
  43. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  44. GRB011019: Subaru Optical Observations
  45. GRB 011030 I-band Observations
  46. GRB 011030 K-band Observations
  47. GRB010921, optical observations
  48. GRB011030 - further refinement WFC position
  49. GRB 011030, Radio observations
  50. GRB011030: radio search
  51. GRB 010921: Possible supernova component
  52. GRB010921, optical observation at early time
  53. GRB 010921, I-band observations
  54. GRB011019, optical observations
  55. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  56. GRB 010921: The afterglow of HETE #1761
  57. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  58. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  59. GRB010923 as seen by BeppoSAX GRBM
  60. GRB010928(=H1770): Localization of a Long GRB by HETE
  61. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  62. GRB010921, negative optical observations
  63. GRB010921 field photometry
  64. H1761: A Bright GRB Detected by HETE
  65. GRB000926, Host Galaxy Observations
  66. GRB001109, Host Galaxy Spectroscopic Observations
  67. Probable SGR or Short Duration GRB Detected by HETE
  68. GCN and HETE status
  69. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  70. GRB 010222 - WHT BVRI images
  71. SGR1900+14 burst seen by HETE: BeppoSAX data
  72. GRB 010629 Optical Observations
  73. SGR1900+14: High Fluence Burst Localized by HETE
  74. GRB010629, optical observations
  75. GRB010629: A Burst Localized by HETE
  76. SGR1900+14: Second Burst Localized by HETE
  77. SGR1900+14: A Burst Localized by HETE
  78. SGR1806-20: A Second, Intense Burst Localized by HETE
  79. SGR1806-20: Localization by HETE
  80. HETE Fully-Automated GCN Notices
  81. GRB000301C: Late-time HST/STIS observation
  82. GRB010518: a faint BeppoSAX detection
  83. GRB000418: HST/STIS Second-epoch Observations
  84. X-ray precursors to the large flare from SGR 1900+14
  85. GRB010427, Gamma Ray Observations
  86. SGR 1900+14: No evidence of extended X-ray emission
  87. SGR 1900+14 : RXTE observations
  88. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  89. SGR 1900+14: Correction to GCN 1049
  90. GRB 010222 /corrections to VBT data
  91. Millimeter observation of SGR 1900+14
  92. SGR 1900+14: Detection of extended X-ray emission
  93. SGR 1900+14, Chandra observations
  94. SGR1900+14, I-band observations
  95. GRB010412, field photometry
  96. Giant flare from SGR1900+14
  97. GRB 010326b Optical Observations
  98. GRB010412: BeppoSAX GRBM and WFC observations
  99. GRB010324, revised field photometry
  100. REVISED LOCATION OF GRB010326A

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