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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"

43623 results found.

  1. GRB011130 (XRF011130) Chandra Observations
  2. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  3. GRB 011130: Magellan spectroscopy
  4. Sub-mm and Centimeter Detections of the Host Galaxy of GRB000418
  5. GRB011130, optical observations
  6. GRB 011130, K band observations
  7. GRB011130, optical observations
  8. GRB011130 (=XRF011130): Second Revised Localization by HETE
  9. GRB 011130 I-band Observation
  10. GRB011130 (XRF011130) optical observations
  11. GRB011130 (XRF011130) SDSS PT i-band observations
  12. XRF011130: Infrared Observations
  13. GRB011130, Radio Observations
  14. Detection of the X-ray afterglow of GRB011121 by BeppoSAX
  15. GRB011130 (=XRF011130), Optical Observations
  16. GRB011130 (=XRF011130): Revised Localization of an X-ray
  17. GRB001109, Radio Monitoring
  18. GRB 011121
  19. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  20. GRB 011121: J-band observations
  21. GRB 011121: NIR observations, host galaxy?
  22. GRB010921 - Milagro GeV/TeV Observations
  23. GRB 011121: HST Scheduled
  24. GRB011121: fainter still
  25. GRB011121: UBRI Observations
  26. GRB011121
  27. GRB 011121: Radio Observations
  28. GRB 011121 J-Band Astrometry
  29. GRB011121: continued decay
  30. GRB 011121: Detection of Bright IR Counterpart
  31. GRB011121: possible redshift, continued decay
  32. GRB011121: fading behavior
  33. GRB011121: possible optical counterpart
  34. GRB011121: BeppoSAX-WFC refined positions
  35. IPN triangulation of GRB011121
  36. BEPPOSAX GRB011121
  37. GRB 011030: TNG K-band observation
  38. XRF011030: J and K band observations
  39. XRF011030: Chandra Observations
  40. GRB 011030: K-band observations
  41. GRB011030: Z-band observations
  42. GRB 011030 R band observations
  43. GRB 011030 I-band Observation
  44. The X-ray Flash 011030 ('GRB 011030')
  45. Non-triggered burst 011030 ("GRB 011030")
  46. The Radio Afterglow from the X-ray Rich GRB 011030
  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. GRB010921, optical observation
  52. GRB 011019 optical observation
  53. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  54. GRB011019: Subaru Optical Observations
  55. GRB 011030 I-band Observations
  56. GRB 011030 K-band Observations
  57. GRB010921, optical observations
  58. GRB 011030, WSRT radio observations
  59. GRB011030 - further refinement WFC position
  60. GRB 011030, Radio observations
  61. GRB011030: radio search
  62. GRB 011030, R-band observations
  63. X-ray rich GRB011030: BeppoSAX refined positions
  64. BeppoSAX ALERT: Possible X-ray rich GRB011030
  65. GRB 010921: Possible supernova component
  66. GRB011019: NEAT Optical Observations
  67. GRB011019: ROTSE-III optical observations
  68. GRB010921, optical observation at early time
  69. GRB 010921, I-band observations
  70. GRB011019: Optical observations
  71. GRB011019, optical observations -- correction
  72. GRB011019, optical observations
  73. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  74. GRB010921: Spectroscopy of the Host Galaxy
  75. GRB 010921: The afterglow of HETE #1761
  76. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  77. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  78. GRB010923 as seen by BeppoSAX GRBM
  79. GRB010928(=H1770): Localization of a Long GRB by HETE
  80. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  81. GRB010921, negative optical observations
  82. GRB010921 field photometry
  83. GRB 010921 DPOSS Images Available
  84. IPN triangulation of GRB010921 (=H1761)
  85. H1761: A Bright GRB Detected by HETE
  86. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  87. HETE Trigger #1760 (GRB 010920B?): a new optical source
  88. HETE Trigger #1759 (GRB 010920?) optical observations
  89. GRB001109, Host Galaxy Astrometry
  90. GRB000926, Host Galaxy Observations
  91. GRB001109, Host Galaxy Spectroscopic Observations
  92. Probable SGR or Short Duration GRB Detected by HETE
  93. GRB000926 Host Galaxy Observations
  94. GRB 010222: HST observations -- host galaxy and late-time decay
  95. BeppoSAX/GRBM detection of GRB 010801
  96. GCN and HETE status
  97. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  98. BeppoSAX/GRBM detection of GRB010728
  99. GRB 010222 - WHT BVRI images
  100. SGR1900+14 burst seen by HETE: BeppoSAX data

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