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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"

35987 results found.

  1. IPN triangulation of GRB020305 (HETE 1939)
  2. GRB020305 (=H1939): Localization of a GRB by HETE
  3. GRB 020305: Optical observations
  4. HST Imaging of the afterglow and host of GRB 011121
  5. GRB 010921: HST Observations
  6. IPN detection and localization of Cygnus X-1 flares
  7. GRB020127: Further VLA Observations of Possible Counterparts
  8. IPN detection of further SGR1900+14 activity
  9. SGR1900+14 activity
  10. IPN/HETE Detection of Bursts from SGR1900+14
  11. IPN Upper Limits to a GRB Associated With SN2002ap
  12. GRB020124 BVRI field photometry
  13. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  14. SN2002ap (SN/GRB?) Echelle spectra
  15. SN2002ap (SN/GRB?) optical spectrographic observations
  16. GRB020127 Optical Observations
  17. SN 2002ap (SN/GRB?)
  18. SN2002ap (SN/GRB?) UBVRI Field Photometry
  19. GRB020127: Chandra Observations and Prospective Counterparts
  20. pre-SN2002ap (SN/GRB?) imaging of M74
  21. SN 2002ap (hypernova / GRB ??): special list on VSNET
  22. Type Ib/c SN2002ap (SN/GRB?)
  23. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  24. GRB020124, optical observations
  25. GRB020127: Optical observations
  26. GRB 020127, I-band observations starting 3.14-hr after the event
  27. IPN detection of further activity from SGR1806-20
  28. IPN triangulation of GRB020127 (=H1902)
  29. GRB010921 Optical Observations
  30. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  31. GRB020124: Optical observations
  32. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  33. GRB020124: Optical observations
  34. GRB 020124: Optical observations
  35. GRB 020124 Optical Observations
  36. IPN triangulation of GRB020124 (HETE 1896)
  37. IPN observations of SGR1806-20
  38. GRB 020124: Optical afterglow
  39. GRB020124(=H1896): Localization of a Long GRB by HETE
  40. GRB optical counterpart candidate in GCN 1217 is M dwarf
  41. Possible optical counterpart to a GRB
  42. GRB011212, Optical Observations
  43. GRB 011211: Detection of the Probable Host Galaxy
  44. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  45. GRB 011211, spectrum and optical photometry
  46. GRB 011130: Optical Observations of X-ray and Radio Sources
  47. GRB 011130, Radio/X-ray Comparison
  48. GRB 011212: optical observation at Asiago
  49. GRB 011211: Evidence for an Optical Break
  50. GRB 011211: TNG Spectroscopic Observations
  51. optical follow-up of GRB(XRF) 011211
  52. GRB 011212: optical observation at Oslo (relayed)
  53. GRB 011211: Optical Spectroscopy
  54. GRB 011211, Optical Observations
  55. GRB011212, BVRI field photometry
  56. GRB011211, BVRI field photometry
  57. GRB011212: Optical observations
  58. GRB 011211: BVRi-band photometry
  59. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  60. Fading of the optical source associated of XRF 011211
  61. GRB 011211 Optical Observations: Likely Afterglow
  62. BeppoSAX Alert: GRB011211(=XRF011211)
  63. GRB 011130: Optical Observations of Chandra Sources
  64. GRB 011130: Optical Observations of Chandra sources
  65. GRB 011130: Magellan spectroscopy
  66. Sub-mm and Centimeter Detections of the Host Galaxy of GRB000418
  67. GRB011130, optical observations
  68. GRB 011130, K band observations
  69. GRB011130, optical observations
  70. GRB 011130 I-band Observation
  71. GRB011130 (XRF011130) optical observations
  72. GRB011130 (XRF011130) SDSS PT i-band observations
  73. Detection of the X-ray afterglow of GRB011121 by BeppoSAX
  74. XRF011130: NEAT Optical Observations
  75. GRB011130 (=XRF011130): Revised Localization of an X-ray
  76. GRB001109, Radio Monitoring
  77. GRB 011121: Errata URL
  78. GRB 011121
  79. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  80. GRB 011121: J-band observations
  81. GRB 011121: NIR observations, host galaxy?
  82. GRB 011121: HST Scheduled
  83. GRB011121: fainter still
  84. Correction: GCN1157 (GRB 011121)
  85. GRB 011121: Radio Observations
  86. GRB 011121 J-Band Astrometry
  87. GRB011121: continued decay
  88. GRB 011121: Detection of Bright IR Counterpart
  89. GRB011121: possible redshift, continued decay
  90. IPN triangulation of GRB011121
  91. BEPPOSAX GRB011121
  92. GRB 011030: TNG K-band observation
  93. XRF011030: Chandra Observations
  94. GRB 011030: K-band observations
  95. GRB 011030 R band observations
  96. GRB 011030 I-band Observation
  97. The X-ray Flash 011030 ('GRB 011030')
  98. Non-triggered burst 011030 ("GRB 011030")
  99. The Radio Afterglow from the X-ray Rich GRB 011030
  100. GRB 010921: HST Detection of the Afterglow and Host Galaxy

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