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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"

35429 results found.

  1. GRB 011130: Optical Observations of Chandra Sources
  2. GRB 011130: Optical Observations of Chandra sources
  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. GRB 011130 I-band Observation
  9. GRB011130 (XRF011130) optical observations
  10. GRB011130 (XRF011130) SDSS PT i-band observations
  11. Detection of the X-ray afterglow of GRB011121 by BeppoSAX
  12. XRF011130: NEAT Optical Observations
  13. GRB011130 (=XRF011130): Revised Localization of an X-ray
  14. GRB001109, Radio Monitoring
  15. GRB 011121: Errata URL
  16. GRB 011121
  17. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  18. GRB 011121: J-band observations
  19. GRB 011121: NIR observations, host galaxy?
  20. GRB 011121: HST Scheduled
  21. GRB011121: fainter still
  22. Correction: GCN1157 (GRB 011121)
  23. GRB 011121: Radio Observations
  24. GRB 011121 J-Band Astrometry
  25. GRB011121: continued decay
  26. GRB 011121: Detection of Bright IR Counterpart
  27. GRB011121: possible redshift, continued decay
  28. IPN triangulation of GRB011121
  29. BEPPOSAX GRB011121
  30. GRB 011030: TNG K-band observation
  31. XRF011030: Chandra Observations
  32. GRB 011030: K-band observations
  33. GRB 011030 R band observations
  34. GRB 011030 I-band Observation
  35. The X-ray Flash 011030 ('GRB 011030')
  36. Non-triggered burst 011030 ("GRB 011030")
  37. The Radio Afterglow from the X-ray Rich GRB 011030
  38. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  39. GRB 970828: HST Observations of the Host Galaxy
  40. GRB 000131: HST Detection of the Host Galaxy
  41. GRB 970828: HST Observations of the Host Galaxy
  42. GRB010921, optical observation
  43. GRB 011019 optical observation
  44. GRB011019: Subaru Optical Observations
  45. GRB 011030 I-band Observations
  46. GRB 011030 K-band Observations
  47. GRB010921, optical observations
  48. GRB 011030, WSRT radio observations
  49. GRB011030 - further refinement WFC position
  50. GRB 011030, Radio observations
  51. GRB 011030, R-band observations
  52. BeppoSAX ALERT: Possible X-ray rich GRB011030
  53. GRB 010921: Possible supernova component
  54. GRB011019: NEAT Optical Observations
  55. GRB010921, optical observation at early time
  56. GRB 010921, I-band observations
  57. GRB011019: Optical observations
  58. GRB011019, optical observations
  59. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  60. GRB010921: Spectroscopy of the Host Galaxy
  61. GRB 010921: The afterglow of HETE #1761
  62. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  63. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  64. GRB010923 as seen by BeppoSAX GRBM
  65. GRB010928(=H1770): Localization of a Long GRB by HETE
  66. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  67. GRB010921, negative optical observations
  68. GRB010921 field photometry
  69. GRB010921 Optical Observations
  70. GRB 010921 DPOSS Images Available
  71. IPN triangulation of GRB010921 (=H1761)
  72. H1761: A Bright GRB Detected by HETE
  73. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  74. HETE Trigger #1760 (GRB 010920B?): a new optical source
  75. HETE Trigger #1759 (GRB 010920?) optical observations
  76. GRB001109, Host Galaxy Astrometry
  77. GRB000926, Host Galaxy Observations
  78. GRB001109, Host Galaxy Spectroscopic Observations
  79. Probable SGR or Short Duration GRB Detected by HETE
  80. GRB000926 Host Galaxy Observations
  81. GRB 010222: HST observations -- host galaxy and late-time decay
  82. BeppoSAX/GRBM detection of GRB 010801
  83. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  84. GRB 010222 - WHT BVRI images
  85. GRB 010629 Optical Observations
  86. GRB010629: Optical Observations
  87. GRB010629, optical observations
  88. IPN triangulation of GRB010629
  89. GRB010629: A Burst Localized by HETE
  90. Possible burst from SGR1806-20
  91. IPN detection of SGR1900+14
  92. GRB 00630: Host Galaxy
  93. IPN triangulation of GRB010613
  94. IPN triangulation of GRB010612
  95. HETE Fully-Automated GCN Notices
  96. GRB000301C: Late-time HST/STIS observation
  97. GRB010518: a faint BeppoSAX detection
  98. GRB000418: HST/STIS Second-epoch Observations
  99. GRB010427, Gamma Ray Observations
  100. SGR1900+14

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