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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"

39191 results found.

  1. SN 2002ap (SN/GRB?)
  2. SN2002ap (SN/GRB?) UBVRI Field Photometry
  3. GRB020127: Chandra Observations and Prospective Counterparts
  4. pre-SN2002ap (SN/GRB?) imaging of M74
  5. SN 2002ap (hypernova / GRB ??): special list on VSNET
  6. Type Ib/c SN2002ap (SN/GRB?)
  7. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  8. GRB020124, optical observations
  9. GRB020127: Optical observations
  10. GRB 020127, I-band observations starting 3.14-hr after the event
  11. IPN detection of further activity from SGR1806-20
  12. IPN triangulation of GRB020127 (=H1902)
  13. GRB010921 Optical Observations
  14. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  15. GRB020124: Optical observations
  16. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  17. GRB020124: Optical observations
  18. GRB 020124: Optical observations
  19. GRB 020124 Optical Observations
  20. IPN triangulation of GRB020124 (HETE 1896)
  21. IPN observations of SGR1806-20
  22. GRB 020124: Optical afterglow
  23. GRB020124(=H1896): Localization of a Long GRB by HETE
  24. GRB optical counterpart candidate in GCN 1217 is M dwarf
  25. Possible optical counterpart to a GRB
  26. GRB011212, Optical Observations
  27. GRB 011211: Detection of the Probable Host Galaxy
  28. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  29. GRB 011211, spectrum and optical photometry
  30. GRB 011130: Optical Observations of X-ray and Radio Sources
  31. GRB 011130, Radio/X-ray Comparison
  32. GRB 011212: optical observation at Asiago
  33. GRB 011211: Evidence for an Optical Break
  34. GRB 011211: TNG Spectroscopic Observations
  35. optical follow-up of GRB(XRF) 011211
  36. GRB 011212: optical observation at Oslo (relayed)
  37. GRB 011211: Optical Spectroscopy
  38. GRB 011211, Optical Observations
  39. GRB011212, BVRI field photometry
  40. GRB011211, BVRI field photometry
  41. GRB011212: Optical observations
  42. GRB 011211: BVRi-band photometry
  43. GRB011212 (=H10001): An X-Ray Rich GRB Detected by HETE
  44. Fading of the optical source associated of XRF 011211
  45. GRB 011211 Optical Observations: Likely Afterglow
  46. BeppoSAX Alert: GRB011211(=XRF011211)
  47. GRB 011130: Optical Observations of Chandra Sources
  48. GRB 011130: Optical Observations of Chandra sources
  49. GRB 011130: Magellan spectroscopy
  50. Sub-mm and Centimeter Detections of the Host Galaxy of GRB000418
  51. GRB011130, optical observations
  52. GRB 011130, K band observations
  53. GRB011130, optical observations
  54. GRB 011130 I-band Observation
  55. GRB011130 (XRF011130) optical observations
  56. GRB011130 (XRF011130) SDSS PT i-band observations
  57. Detection of the X-ray afterglow of GRB011121 by BeppoSAX
  58. XRF011130: NEAT Optical Observations
  59. GRB011130 (=XRF011130): Revised Localization of an X-ray
  60. GRB001109, Radio Monitoring
  61. GRB 011121: Errata URL
  62. GRB 011121
  63. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  64. GRB 011121: J-band observations
  65. GRB 011121: NIR observations, host galaxy?
  66. GRB 011121: HST Scheduled
  67. GRB011121: fainter still
  68. Correction: GCN1157 (GRB 011121)
  69. GRB011121: UBRI Observations
  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. GRB011121: possible optical counterpart
  76. IPN triangulation of GRB011121
  77. BEPPOSAX GRB011121
  78. GRB 011030: TNG K-band observation
  79. XRF011030: Chandra Observations
  80. GRB 011030: K-band observations
  81. GRB 011030 R band observations
  82. GRB 011030 I-band Observation
  83. The X-ray Flash 011030 ('GRB 011030')
  84. Non-triggered burst 011030 ("GRB 011030")
  85. The Radio Afterglow from the X-ray Rich GRB 011030
  86. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  87. GRB 970828: HST Observations of the Host Galaxy
  88. GRB 000131: HST Detection of the Host Galaxy
  89. GRB 970828: HST Observations of the Host Galaxy
  90. GRB010921, optical observation
  91. GRB 011019 optical observation
  92. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  93. GRB011019: Subaru Optical Observations
  94. GRB 011030 I-band Observations
  95. GRB 011030 K-band Observations
  96. GRB010921, optical observations
  97. GRB 011030, WSRT radio observations
  98. GRB011030 - further refinement WFC position
  99. GRB 011030, Radio observations
  100. GRB 011030, R-band observations

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