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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"

45457 results found.

  1. GRB020305: Properties of the Candidate Optical Afterglow
  2. GRB 011121: HST Observations reveal an intermediate-time multicolor
  3. GRB011121, possible supernova association
  4. GRB011130 (XRF011130) Second Epoch Chandra Observations
  5. GRB020305: Subaru Optical Observations
  6. GRB 020305: Optical observations
  7. XRF/GRB 011030 Images
  8. XRF/GRB 011030: Detection of the Probable Host Galaxy
  9. GRB 020305: Candidate optical afterglow
  10. Type Ic SN2002bl (SN/GRB?) Radio Observations
  11. GRB020305, optical observations
  12. GRB020305: Optical Observations
  13. IPN triangulation of GRB020305 (HETE 1939)
  14. GRB020305 (=H1939): Localization of a GRB by HETE
  15. GRB 020305: Optical observations
  16. HST Imaging of the afterglow and host of GRB 011121
  17. GRB 010921: HST Observations
  18. IPN detection and localization of Cygnus X-1 flares
  19. GRB020127: Further VLA Observations of Possible Counterparts
  20. RXTE Observations of SGR 1900+14
  21. IPN detection of further SGR1900+14 activity
  22. SGR1900+14 activity
  23. IPN/HETE Detection of Bursts from SGR1900+14
  24. IPN Upper Limits to a GRB Associated With SN2002ap
  25. GRB020124 BVRI field photometry
  26. GRB020127: Palomar and VLA Observations of Possible Counterparts
  27. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  28. SN2002ap (SN/GRB?) Echelle spectra
  29. SN2002ap (SN/GRB?) optical spectrographic observations
  30. GRB020127, WSRT radio observations
  31. GRB020127 Optical Observations
  32. SN 2002ap (SN/GRB?)
  33. SN 2002ap in M74
  34. SN2002ap (SN/GRB?) UBVRI Field Photometry
  35. GRB020127: Chandra Observations and Prospective Counterparts
  36. pre-SN2002ap (SN/GRB?) imaging of M74
  37. SN 2002ap (hypernova / GRB ??): special list on VSNET
  38. Type Ib/c SN2002ap (SN/GRB?)
  39. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  40. GRB020124, optical observations
  41. GRB020127: Optical observations
  42. GRB 020127, I-band observations starting 3.14-hr after the event
  43. IPN detection of further activity from SGR1806-20
  44. IPN triangulation of GRB020127 (=H1902)
  45. GRB020127 Optical Observations -- Erratum to GCN 1230
  46. GRB010921 Optical Observations
  47. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  48. GRB020124: Optical observations
  49. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  50. GRB020124: Optical observations
  51. GRB 020124: Optical observations
  52. GRB 020124 Optical Observations
  53. IPN triangulation of GRB020124 (HETE 1896)
  54. IPN observations of SGR1806-20
  55. GRB 020124: Optical afterglow
  56. GRB020124(=H1896): Localization of a Long GRB by HETE
  57. HETE 1896: Optical observations
  58. GRB optical counterpart candidate in GCN 1217 is M dwarf
  59. Possible optical counterpart to a GRB
  60. GRB011212, Optical Observations
  61. GRB011211: BeppoSAX/GRBM data
  62. Optical polarization observations for GRB011211
  63. GRB 011211: Detection of the Probable Host Galaxy
  64. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  65. Color indices of the afterglow of GRB011211
  66. GRB011212: Optical observations at Gunma
  67. GRB 011211, spectrum and optical photometry
  68. GRB 011130: Optical Observations of X-ray and Radio Sources
  69. GRB 011130, Radio/X-ray Comparison
  70. GRB011212: Optical observations
  71. GRB 011212: optical observation at Asiago
  72. GRB 011211: Evidence for an Optical Break
  73. GRB 011211: TNG Spectroscopic Observations
  74. optical follow-up of GRB(XRF) 011211
  75. GRB 011212: optical observation at Oslo (relayed)
  76. GRB 011211: Optical Spectroscopy
  77. GRB 011211, Optical Observations
  78. GRB011212, BVRI field photometry
  79. GRB011211, BVRI field photometry
  80. GRB011212: Optical observations
  81. GRB 011211: BVRi-band photometry
  82. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  83. Fading of the optical source associated of XRF 011211
  84. XMM-Newton observation of GRB011211
  85. GRB 011211 Optical Observations: Likely Afterglow
  86. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  87. GRB011211(=XRF011211): BeppoSAX refined positions
  88. BeppoSAX Alert: GRB011211(=XRF011211)
  89. GRB 011130: Optical Observations of Chandra Sources
  90. GRB 011130: Optical Observations of Chandra sources
  91. GRB011130 (XRF011130) Chandra Observations
  92. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  93. GRB 011130: Magellan spectroscopy
  94. Sub-mm and Centimeter Detections of the Host Galaxy of GRB000418
  95. GRB011130, optical observations
  96. GRB 011130, K band observations
  97. GRB011130, optical observations
  98. GRB011130 (=XRF011130): Second Revised Localization by HETE
  99. GRB 011130 I-band Observation
  100. GRB011130 (XRF011130) optical observations

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