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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"

32494 results found.

  1. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  2. GRB020124: Optical observations
  3. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  4. GRB020124: Optical observations
  5. GRB 020124: Optical observations
  6. GRB 020124 Optical Observations
  7. IPN triangulation of GRB020124 (HETE 1896)
  8. GRB 020124: Optical afterglow
  9. GRB020124(=H1896): Localization of a Long GRB by HETE
  10. GRB optical counterpart candidate in GCN 1217 is M dwarf
  11. GRB011212, Optical Observations
  12. GRB011211: BeppoSAX/GRBM data
  13. Optical polarization observations for GRB011211
  14. Color indices of the afterglow of GRB011211
  15. GRB011212: Optical observations at Gunma
  16. GRB 011211, spectrum and optical photometry
  17. GRB 011130: Optical Observations of X-ray and Radio Sources
  18. GRB 011130, Radio/X-ray Comparison
  19. GRB011212: Optical observations
  20. GRB 011212: optical observation at Asiago
  21. GRB 011211: Evidence for an Optical Break
  22. GRB 011211: TNG Spectroscopic Observations
  23. optical follow-up of GRB(XRF) 011211
  24. GRB 011212: optical observation at Oslo (relayed)
  25. GRB 011211: Optical Spectroscopy
  26. GRB 011211, Optical Observations
  27. GRB011212, BVRI field photometry
  28. GRB011211, BVRI field photometry
  29. GRB011212: Optical observations
  30. GRB 011211: BVRi-band photometry
  31. Fading of the optical source associated of XRF 011211
  32. XMM-Newton observation of GRB011211
  33. GRB 011211 Optical Observations: Likely Afterglow
  34. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  35. GRB 011130: Optical Observations of Chandra Sources
  36. GRB 011130: Optical Observations of Chandra sources
  37. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  38. GRB 011130: Magellan spectroscopy
  39. GRB011130, optical observations
  40. GRB011130, optical observations
  41. GRB011130 (=XRF011130): Second Revised Localization by HETE
  42. GRB 011130 I-band Observation
  43. GRB011130 (XRF011130) optical observations
  44. GRB011130 (XRF011130) SDSS PT i-band observations
  45. XRF011130: Infrared Observations
  46. GRB011130, Radio Observations
  47. Detection of the X-ray afterglow of GRB011121 by BeppoSAX
  48. GRB011130 (=XRF011130), Optical Observations
  49. XRF011130: NEAT Optical Observations
  50. GRB011130 (=XRF011130): Revised Localization of an X-ray
  51. GRB001109, Radio Monitoring
  52. GRB 011121: Errata URL
  53. GRB 011121
  54. GRB 011121: J-band observations
  55. GRB 011121: NIR observations, host galaxy?
  56. GRB010921 - Milagro GeV/TeV Observations
  57. GRB 011121: HST Scheduled
  58. GRB011121: fainter still
  59. Correction: GCN1157 (GRB 011121)
  60. GRB011121: UBRI Observations
  61. GRB011121
  62. GRB 011121: Radio Observations
  63. GRB 011121 J-Band Astrometry
  64. GRB011121: continued decay
  65. GRB 011121: Detection of Bright IR Counterpart
  66. GRB011121: possible redshift, continued decay
  67. GRB011121: fading behavior
  68. GRB011121: possible optical counterpart
  69. IPN triangulation of GRB011121
  70. GRB 011030: TNG K-band observation
  71. XRF011030: J and K band observations
  72. XRF011030: Chandra Observations
  73. GRB 011030: K-band observations
  74. GRB011030: Z-band observations
  75. GRB 011030 I-band Observation
  76. The X-ray Flash 011030 ('GRB 011030')
  77. The Radio Afterglow from the X-ray Rich GRB 011030
  78. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  79. GRB 000131: HST Detection of the Host Galaxy
  80. GRB 011019 optical observation
  81. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  82. GRB011019: Subaru Optical Observations
  83. GRB 011030 I-band Observations
  84. GRB 011030 K-band Observations
  85. GRB010921, optical observations
  86. GRB 011030, WSRT radio observations
  87. GRB011030 - further refinement WFC position
  88. GRB 011030, Radio observations
  89. GRB011030: radio search
  90. GRB 011030, R-band observations
  91. BeppoSAX ALERT: Possible X-ray rich GRB011030
  92. GRB 010921: Possible supernova component
  93. GRB011019: ROTSE-III optical observations
  94. GRB 010921, I-band observations
  95. GRB011019: Optical observations
  96. GRB011019, optical observations -- correction
  97. GRB011019, optical observations
  98. GRB010921: Spectroscopy of the Host Galaxy
  99. GRB 010921: The afterglow of HETE #1761
  100. Optical Observations of the field of HETE trigger #1793/GRB 011012?

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