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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"
  1. Type Ic SN2002bl (SN/GRB?) Radio Observations
  2. GRB020305, optical observations
  3. GRB020305: Optical Observations
  4. IPN triangulation of GRB020305 (HETE 1939)
  5. GRB020305 (=H1939): Localization of a GRB by HETE
  6. GRB 020305: Optical observations
  7. HST Imaging of the afterglow and host of GRB 011121
  8. GRB 010921: HST Observations
  9. IPN detection and localization of Cygnus X-1 flares
  10. GRB020127: Further VLA Observations of Possible Counterparts
  11. RXTE Observations of SGR 1900+14
  12. IPN detection of further SGR1900+14 activity
  13. SGR1900+14 activity
  14. IPN/HETE Detection of Bursts from SGR1900+14
  15. IPN Upper Limits to a GRB Associated With SN2002ap
  16. GRB020124 BVRI field photometry
  17. GRB020127: Palomar and VLA Observations of Possible Counterparts
  18. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  19. SN2002ap (SN/GRB?) Echelle spectra
  20. SN2002ap (SN/GRB?) optical spectrographic observations
  21. GRB020127, WSRT radio observations
  22. GRB020127 Optical Observations
  23. SN 2002ap (SN/GRB?)
  24. SN 2002ap in M74
  25. SN2002ap (SN/GRB?) UBVRI Field Photometry
  26. GRB020127: Chandra Observations and Prospective Counterparts
  27. pre-SN2002ap (SN/GRB?) imaging of M74
  28. SN 2002ap (hypernova / GRB ??): special list on VSNET
  29. Type Ib/c SN2002ap (SN/GRB?)
  30. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  31. GRB020124, optical observations
  32. GRB020127: Optical observations
  33. GRB 020127, I-band observations starting 3.14-hr after the event
  34. IPN detection of further activity from SGR1806-20
  35. IPN triangulation of GRB020127 (=H1902)
  36. GRB020127 Optical Observations -- Erratum to GCN 1230
  37. GRB010921 Optical Observations
  38. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  39. GRB020124: Optical observations
  40. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  41. GRB020124: Optical observations
  42. GRB 020124: Optical observations
  43. GRB 020124 Optical Observations
  44. IPN triangulation of GRB020124 (HETE 1896)
  45. IPN observations of SGR1806-20
  46. GRB 020124: Optical afterglow
  47. GRB020124(=H1896): Localization of a Long GRB by HETE
  48. HETE 1896: Optical observations
  49. GRB optical counterpart candidate in GCN 1217 is M dwarf
  50. Possible optical counterpart to a GRB
  51. GRB011212, Optical Observations
  52. GRB011211: BeppoSAX/GRBM data
  53. Optical polarization observations for GRB011211
  54. GRB 011211: Detection of the Probable Host Galaxy
  55. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  56. Color indices of the afterglow of GRB011211
  57. GRB011212: Optical observations at Gunma
  58. GRB 011211, spectrum and optical photometry
  59. GRB 011130: Optical Observations of X-ray and Radio Sources
  60. GRB 011130, Radio/X-ray Comparison
  61. GRB011212: Optical observations
  62. GRB 011212: optical observation at Asiago
  63. GRB 011211: Evidence for an Optical Break
  64. GRB 011211: TNG Spectroscopic Observations
  65. optical follow-up of GRB(XRF) 011211
  66. GRB 011212: optical observation at Oslo (relayed)
  67. GRB 011211: Optical Spectroscopy
  68. GRB 011211, Optical Observations
  69. GRB011212, BVRI field photometry
  70. GRB011211, BVRI field photometry
  71. GRB011212: Optical observations
  72. GRB 011211: BVRi-band photometry
  73. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  74. Fading of the optical source associated of XRF 011211
  75. XMM-Newton observation of GRB011211
  76. GRB 011211 Optical Observations: Likely Afterglow
  77. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  78. GRB011211(=XRF011211): BeppoSAX refined positions
  79. BeppoSAX Alert: GRB011211(=XRF011211)
  80. GRB 011130: Optical Observations of Chandra Sources
  81. GRB 011130: Optical Observations of Chandra sources
  82. GRB011130 (XRF011130) Chandra Observations
  83. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  84. GRB 011130: Magellan spectroscopy
  85. Sub-mm and Centimeter Detections of the Host Galaxy of GRB000418
  86. GRB011130, optical observations
  87. GRB 011130, K band observations
  88. GRB011130, optical observations
  89. GRB011130 (=XRF011130): Second Revised Localization by HETE
  90. GRB 011130 I-band Observation
  91. GRB011130 (XRF011130) optical observations
  92. GRB011130 (XRF011130) SDSS PT i-band observations
  93. XRF011130: Infrared Observations
  94. GRB011130, Radio Observations
  95. Detection of the X-ray afterglow of GRB011121 by BeppoSAX
  96. GRB011130 (=XRF011130), Optical Observations
  97. XRF011130: NEAT Optical Observations
  98. GRB011130 (=XRF011130): Revised Localization of an X-ray
  99. GRB001109, Radio Monitoring
  100. GRB 011121: Errata URL

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