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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.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

35272 results found.

  1. GRB020127 Optical Observations
  2. SN 2002ap (SN/GRB?)
  3. SN2002ap (SN/GRB?) UBVRI Field Photometry
  4. GRB020127: Chandra Observations and Prospective Counterparts
  5. pre-SN2002ap (SN/GRB?) imaging of M74
  6. SN 2002ap (hypernova / GRB ??): special list on VSNET
  7. Type Ib/c SN2002ap (SN/GRB?)
  8. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  9. GRB020124, optical observations
  10. GRB020127: Optical observations
  11. GRB 020127, I-band observations starting 3.14-hr after the event
  12. IPN detection of further activity from SGR1806-20
  13. IPN triangulation of GRB020127 (=H1902)
  14. GRB010921 Optical Observations
  15. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  16. GRB020124: Optical observations
  17. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  18. GRB020124: Optical observations
  19. GRB 020124: Optical observations
  20. GRB 020124 Optical Observations
  21. IPN triangulation of GRB020124 (HETE 1896)
  22. IPN observations of SGR1806-20
  23. GRB 020124: Optical afterglow
  24. GRB020124(=H1896): Localization of a Long GRB by HETE
  25. GRB optical counterpart candidate in GCN 1217 is M dwarf
  26. Possible optical counterpart to a GRB
  27. GRB011212, Optical Observations
  28. GRB 011211: Detection of the Probable Host Galaxy
  29. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  30. GRB 011211, spectrum and optical photometry
  31. GRB 011130: Optical Observations of X-ray and Radio Sources
  32. GRB 011130, Radio/X-ray Comparison
  33. GRB 011212: optical observation at Asiago
  34. GRB 011211: Evidence for an Optical Break
  35. GRB 011211: TNG Spectroscopic Observations
  36. optical follow-up of GRB(XRF) 011211
  37. GRB 011212: optical observation at Oslo (relayed)
  38. GRB 011211: Optical Spectroscopy
  39. GRB 011211, Optical Observations
  40. GRB011212, BVRI field photometry
  41. GRB011211, BVRI field photometry
  42. GRB011212: Optical observations
  43. GRB 011211: BVRi-band photometry
  44. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  45. Fading of the optical source associated of XRF 011211
  46. GRB 011211 Optical Observations: Likely Afterglow
  47. BeppoSAX Alert: GRB011211(=XRF011211)
  48. GRB 011130: Optical Observations of Chandra Sources
  49. GRB 011130: Optical Observations of Chandra sources
  50. GRB 011130: Magellan spectroscopy
  51. Sub-mm and Centimeter Detections of the Host Galaxy of GRB000418
  52. GRB011130, optical observations
  53. GRB 011130, K band observations
  54. GRB011130, optical observations
  55. GRB 011130 I-band Observation
  56. GRB011130 (XRF011130) optical observations
  57. GRB011130 (XRF011130) SDSS PT i-band observations
  58. Detection of the X-ray afterglow of GRB011121 by BeppoSAX
  59. XRF011130: NEAT Optical Observations
  60. GRB011130 (=XRF011130): Revised Localization of an X-ray
  61. GRB001109, Radio Monitoring
  62. GRB 011121: Errata URL
  63. GRB 011121
  64. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  65. GRB 011121: J-band observations
  66. GRB 011121: NIR observations, host galaxy?
  67. GRB 011121: HST Scheduled
  68. GRB011121: fainter still
  69. Correction: GCN1157 (GRB 011121)
  70. GRB 011121: Radio Observations
  71. GRB 011121 J-Band Astrometry
  72. GRB011121: continued decay
  73. GRB 011121: Detection of Bright IR Counterpart
  74. GRB011121: possible redshift, continued decay
  75. IPN triangulation of GRB011121
  76. BEPPOSAX GRB011121
  77. GRB 011030: TNG K-band observation
  78. XRF011030: Chandra Observations
  79. GRB 011030: K-band observations
  80. GRB 011030 R band observations
  81. GRB 011030 I-band Observation
  82. The X-ray Flash 011030 ('GRB 011030')
  83. Non-triggered burst 011030 ("GRB 011030")
  84. The Radio Afterglow from the X-ray Rich GRB 011030
  85. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  86. GRB 970828: HST Observations of the Host Galaxy
  87. GRB 000131: HST Detection of the Host Galaxy
  88. GRB 970828: HST Observations of the Host Galaxy
  89. GRB010921, optical observation
  90. GRB 011019 optical observation
  91. GRB011019: Subaru Optical Observations
  92. GRB 011030 I-band Observations
  93. GRB 011030 K-band Observations
  94. GRB010921, optical observations
  95. GRB 011030, WSRT radio observations
  96. GRB011030 - further refinement WFC position
  97. GRB 011030, Radio observations
  98. GRB 011030, R-band observations
  99. BeppoSAX ALERT: Possible X-ray rich GRB011030
  100. GRB 010921: Possible supernova component

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