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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"

25038 results found.

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

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