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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"

28056 results found.

  1. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  2. SN2002ap (SN/GRB?) Echelle spectra
  3. GRB020127 Optical Observations
  4. SN 2002ap in M74
  5. SN2002ap (SN/GRB?) UBVRI Field Photometry
  6. GRB020127: Chandra Observations and Prospective Counterparts
  7. pre-SN2002ap (SN/GRB?) imaging of M74
  8. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  9. GRB020124, optical observations
  10. GRB 020127, I-band observations starting 3.14-hr after the event
  11. GRB010921 Optical Observations
  12. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  13. GRB020124: Optical observations
  14. GRB 020124: Optical observations
  15. GRB 020124: Optical afterglow
  16. GRB020124(=H1896): Localization of a Long GRB by HETE
  17. Possible optical counterpart to a GRB
  18. GRB011212, Optical Observations
  19. Optical polarization observations for GRB011211
  20. GRB 011211: Detection of the Probable Host Galaxy
  21. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  22. GRB 011130: Optical Observations of X-ray and Radio Sources
  23. GRB 011212: optical observation at Asiago
  24. GRB 011211: Evidence for an Optical Break
  25. GRB 011211: TNG Spectroscopic Observations
  26. optical follow-up of GRB(XRF) 011211
  27. GRB 011212: optical observation at Oslo (relayed)
  28. GRB 011211, Optical Observations
  29. GRB011212, BVRI field photometry
  30. GRB011211, BVRI field photometry
  31. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  32. Fading of the optical source associated of XRF 011211
  33. GRB 011211 Optical Observations: Likely Afterglow
  34. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  35. GRB011130 (XRF011130) Chandra Observations
  36. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  37. GRB 011130, K band observations
  38. GRB011130, optical observations
  39. GRB011130 (=XRF011130): Second Revised Localization by HETE
  40. GRB011130 (XRF011130) SDSS PT i-band observations
  41. XRF011130: Infrared Observations
  42. GRB 011121
  43. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  44. GRB 011121: J-band observations
  45. GRB 011121: NIR observations, host galaxy?
  46. GRB011121: UBRI Observations
  47. GRB 011121 J-Band Astrometry
  48. GRB 011121: Detection of Bright IR Counterpart
  49. GRB011121: possible redshift, continued decay
  50. GRB 011030: TNG K-band observation
  51. XRF011030: J and K band observations
  52. XRF011030: Chandra Observations
  53. GRB011030: Z-band observations
  54. GRB 011030 R band observations
  55. GRB 011030 I-band Observation
  56. The X-ray Flash 011030 ('GRB 011030')
  57. Non-triggered burst 011030 ("GRB 011030")
  58. The Radio Afterglow from the X-ray Rich GRB 011030
  59. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  60. GRB 970828: HST Observations of the Host Galaxy
  61. GRB 000131: HST Detection of the Host Galaxy
  62. GRB 970828: HST Observations of the Host Galaxy
  63. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  64. GRB011019: Subaru Optical Observations
  65. GRB 011030 I-band Observations
  66. GRB 011030 K-band Observations
  67. GRB010921, optical observations
  68. GRB011030 - further refinement WFC position
  69. GRB 011030, Radio observations
  70. GRB011030: radio search
  71. GRB 010921: Possible supernova component
  72. GRB010921, optical observation at early time
  73. GRB 010921, I-band observations
  74. GRB011019, optical observations
  75. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  76. GRB 010921: The afterglow of HETE #1761
  77. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  78. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  79. GRB010923 as seen by BeppoSAX GRBM
  80. GRB010928(=H1770): Localization of a Long GRB by HETE
  81. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  82. GRB010921, negative optical observations
  83. GRB010921 field photometry
  84. H1761: A Bright GRB Detected by HETE
  85. GRB000926, Host Galaxy Observations
  86. GRB001109, Host Galaxy Spectroscopic Observations
  87. Probable SGR or Short Duration GRB Detected by HETE
  88. GCN and HETE status
  89. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  90. GRB 010222 - WHT BVRI images
  91. SGR1900+14 burst seen by HETE: BeppoSAX data
  92. GRB 010629 Optical Observations
  93. SGR1900+14: High Fluence Burst Localized by HETE
  94. GRB010629, optical observations
  95. GRB010629: A Burst Localized by HETE
  96. SGR1900+14: Second Burst Localized by HETE
  97. SGR1900+14: A Burst Localized by HETE
  98. SGR1806-20: A Second, Intense Burst Localized by HETE
  99. SGR1806-20: Localization by HETE
  100. HETE Fully-Automated GCN Notices

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