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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"

36180 results found.

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

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