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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"

38349 results found.

  1. RXTE Observations of SGR 1900+14
  2. IPN detection of further SGR1900+14 activity
  3. SGR1900+14 activity
  4. IPN/HETE Detection of Bursts from SGR1900+14
  5. IPN Upper Limits to a GRB Associated With SN2002ap
  6. GRB020124 BVRI field photometry
  7. GRB020127: Palomar and VLA Observations of Possible Counterparts
  8. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  9. SN2002ap (SN/GRB?) Echelle spectra
  10. SN2002ap (SN/GRB?) optical spectrographic observations
  11. GRB020127, WSRT radio observations
  12. GRB020127 Optical Observations
  13. SN 2002ap (SN/GRB?)
  14. SN 2002ap in M74
  15. SN2002ap (SN/GRB?) UBVRI Field Photometry
  16. GRB020127: Chandra Observations and Prospective Counterparts
  17. pre-SN2002ap (SN/GRB?) imaging of M74
  18. SN 2002ap (hypernova / GRB ??): special list on VSNET
  19. Type Ib/c SN2002ap (SN/GRB?)
  20. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  21. GRB 020127, I-band observations starting 3.14-hr after the event
  22. IPN detection of further activity from SGR1806-20
  23. IPN triangulation of GRB020127 (=H1902)
  24. GRB010921 Optical Observations
  25. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  26. GRB020124: Optical observations
  27. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  28. GRB020124: Optical observations
  29. GRB 020124: Optical observations
  30. GRB 020124 Optical Observations
  31. IPN triangulation of GRB020124 (HETE 1896)
  32. IPN observations of SGR1806-20
  33. GRB 020124: Optical afterglow
  34. GRB020124(=H1896): Localization of a Long GRB by HETE
  35. HETE 1896: Optical observations
  36. GRB optical counterpart candidate in GCN 1217 is M dwarf
  37. Possible optical counterpart to a GRB
  38. GRB011212, Optical Observations
  39. Optical polarization observations for GRB011211
  40. GRB 011211: Detection of the Probable Host Galaxy
  41. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  42. GRB 011211, spectrum and optical photometry
  43. GRB 011130: Optical Observations of X-ray and Radio Sources
  44. GRB 011130, Radio/X-ray Comparison
  45. GRB011212: Optical observations
  46. GRB 011212: optical observation at Asiago
  47. GRB 011211: Evidence for an Optical Break
  48. GRB 011211: TNG Spectroscopic Observations
  49. optical follow-up of GRB(XRF) 011211
  50. GRB 011212: optical observation at Oslo (relayed)
  51. GRB 011211: Optical Spectroscopy
  52. GRB 011211, Optical Observations
  53. GRB011212, BVRI field photometry
  54. GRB011211, BVRI field photometry
  55. GRB011212: Optical observations
  56. GRB 011211: BVRi-band photometry
  57. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  58. Fading of the optical source associated of XRF 011211
  59. GRB 011211 Optical Observations: Likely Afterglow
  60. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  61. GRB011211(=XRF011211): BeppoSAX refined positions
  62. BeppoSAX Alert: GRB011211(=XRF011211)
  63. GRB 011130: Optical Observations of Chandra Sources
  64. GRB 011130: Optical Observations of Chandra sources
  65. GRB011130 (XRF011130) Chandra Observations
  66. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  67. GRB 011130: Magellan spectroscopy
  68. Sub-mm and Centimeter Detections of the Host Galaxy of GRB000418
  69. GRB011130, optical observations
  70. GRB 011130, K band observations
  71. GRB011130, optical observations
  72. GRB011130 (=XRF011130): Second Revised Localization by HETE
  73. GRB 011130 I-band Observation
  74. GRB011130 (XRF011130) SDSS PT i-band observations
  75. XRF011130: Infrared Observations
  76. GRB011130, Radio Observations
  77. Detection of the X-ray afterglow of GRB011121 by BeppoSAX
  78. GRB011130 (=XRF011130), Optical Observations
  79. XRF011130: NEAT Optical Observations
  80. GRB011130 (=XRF011130): Revised Localization of an X-ray
  81. GRB001109, Radio Monitoring
  82. GRB 011121
  83. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  84. GRB 011121: J-band observations
  85. GRB 011121: NIR observations, host galaxy?
  86. GRB010921 - Milagro GeV/TeV Observations
  87. GRB 011121: HST Scheduled
  88. GRB011121
  89. GRB 011121: Radio Observations
  90. GRB 011121 J-Band Astrometry
  91. GRB 011121: Detection of Bright IR Counterpart
  92. GRB011121: possible redshift, continued decay
  93. GRB011121: fading behavior
  94. GRB011121: possible optical counterpart
  95. GRB011121: BeppoSAX-WFC refined positions
  96. IPN triangulation of GRB011121
  97. BEPPOSAX GRB011121
  98. GRB 011030: TNG K-band observation
  99. XRF011030: J and K band observations
  100. GRB011030, optical observation

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