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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"

35437 results found.

  1. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  2. GRB 020321: Infrared observations
  3. GRB 020322: BeppoSAX observations of the X-ray afterglow
  4. SN 2002ap - peak brightness date (SN/GRB?)
  5. GRB 020322, Radio observations
  6. Near-Infrared Observations of GRB020322 at TIRGO
  7. GRB 020321, Radio Observations
  8. GRB 020322: Optical Observations
  9. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  10. GRB 020321: Optical observations
  11. GRB020317 BVRI field photometry
  12. GRB011211 revised BVRI field photometry
  13. GRB020305 BVRI field photometry
  14. GRB020322 BVRI field photometry
  15. GRB 020322 optical observations
  16. GRB 020322 optical observation
  17. GRB020317 : Near IR Observations from Mt Abu Observatory
  18. GRB 020322: Optical Sources and Improved Astrometry
  19. GRB020322, optical observations
  20. GRB 020322: Optical candidate
  21. GRB020322: BeppoSAX/NFI Observations
  22. Bepposax GRB020322 The second springtime BSAX GRB
  23. GRB 020321: Optical observations
  24. GRB 011121: Fourth Epoch of HST Imaging
  25. GRB020317: optical observations
  26. GRB020321 optical observations
  27. GRB020321: BeppoSAX/NFI Observations
  28. GRB020321: a faint BeppoSAX detection
  29. GRB 020317 : KISO Optical Observations
  30. BeppoSAX ALERT: GRB020321, the "Springtime Burst"
  31. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  32. GRB 020305: Optical Observations
  33. GRB020317, optical observations
  34. GRB 020317: Optical observations
  35. GRB 011121: Third HST Epoch
  36. GRB020305: Properties of the Candidate Optical Afterglow
  37. GRB 011121: HST Observations reveal an intermediate-time multicolor
  38. GRB011121, possible supernova association
  39. GRB011130 (XRF011130) Second Epoch Chandra Observations
  40. GRB020305: Subaru Optical Observations
  41. GRB 020305: Optical observations
  42. XRF/GRB 011030 Images
  43. XRF/GRB 011030: Detection of the Probable Host Galaxy
  44. GRB 020305: Candidate optical afterglow
  45. Type Ic SN2002bl (SN/GRB?) Radio Observations
  46. GRB020305: Optical Observations
  47. IPN triangulation of GRB020305 (HETE 1939)
  48. GRB020305 (=H1939): Localization of a GRB by HETE
  49. GRB 020305: Optical observations
  50. HST Imaging of the afterglow and host of GRB 011121
  51. GRB 010921: HST Observations
  52. IPN detection and localization of Cygnus X-1 flares
  53. GRB020127: Further VLA Observations of Possible Counterparts
  54. IPN detection of further SGR1900+14 activity
  55. SGR1900+14 activity
  56. IPN/HETE Detection of Bursts from SGR1900+14
  57. IPN Upper Limits to a GRB Associated With SN2002ap
  58. GRB020124 BVRI field photometry
  59. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  60. SN2002ap (SN/GRB?) Echelle spectra
  61. SN2002ap (SN/GRB?) optical spectrographic observations
  62. GRB020127 Optical Observations
  63. SN 2002ap (SN/GRB?)
  64. SN2002ap (SN/GRB?) UBVRI Field Photometry
  65. GRB020127: Chandra Observations and Prospective Counterparts
  66. pre-SN2002ap (SN/GRB?) imaging of M74
  67. SN 2002ap (hypernova / GRB ??): special list on VSNET
  68. Type Ib/c SN2002ap (SN/GRB?)
  69. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  70. GRB020124, optical observations
  71. GRB020127: Optical observations
  72. GRB 020127, I-band observations starting 3.14-hr after the event
  73. IPN detection of further activity from SGR1806-20
  74. IPN triangulation of GRB020127 (=H1902)
  75. GRB010921 Optical Observations
  76. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  77. GRB020124: Optical observations
  78. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  79. GRB020124: Optical observations
  80. GRB 020124: Optical observations
  81. GRB 020124 Optical Observations
  82. IPN triangulation of GRB020124 (HETE 1896)
  83. IPN observations of SGR1806-20
  84. GRB 020124: Optical afterglow
  85. GRB020124(=H1896): Localization of a Long GRB by HETE
  86. GRB optical counterpart candidate in GCN 1217 is M dwarf
  87. Possible optical counterpart to a GRB
  88. GRB011212, Optical Observations
  89. GRB 011211: Detection of the Probable Host Galaxy
  90. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  91. GRB 011211, spectrum and optical photometry
  92. GRB 011130: Optical Observations of X-ray and Radio Sources
  93. GRB 011130, Radio/X-ray Comparison
  94. GRB 011212: optical observation at Asiago
  95. GRB 011211: Evidence for an Optical Break
  96. GRB 011211: TNG Spectroscopic Observations
  97. optical follow-up of GRB(XRF) 011211
  98. GRB 011212: optical observation at Oslo (relayed)
  99. GRB 011211: Optical Spectroscopy
  100. GRB 011211, Optical Observations

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