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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"

35441 results found.

  1. GRB020331 field photometry
  2. GRB 020331 Optical Observations
  3. GRB 020331, NIR observations
  4. GRB 020331: Optical observations
  5. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  6. GRB 020321: Infrared observations
  7. GRB 020322: BeppoSAX observations of the X-ray afterglow
  8. SN 2002ap - peak brightness date (SN/GRB?)
  9. GRB 020322, Radio observations
  10. Near-Infrared Observations of GRB020322 at TIRGO
  11. GRB 020321, Radio Observations
  12. GRB 020322: Optical Observations
  13. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  14. GRB 020321: Optical observations
  15. GRB020317 BVRI field photometry
  16. GRB011211 revised BVRI field photometry
  17. GRB020305 BVRI field photometry
  18. GRB020322 BVRI field photometry
  19. GRB 020322 optical observations
  20. GRB 020322 optical observation
  21. GRB020317 : Near IR Observations from Mt Abu Observatory
  22. GRB 020322: Optical Sources and Improved Astrometry
  23. GRB020322, optical observations
  24. GRB 020322: Optical candidate
  25. GRB020322: BeppoSAX/NFI Observations
  26. Bepposax GRB020322 The second springtime BSAX GRB
  27. GRB 020321: Optical observations
  28. GRB 011121: Fourth Epoch of HST Imaging
  29. GRB020317: optical observations
  30. GRB020321 optical observations
  31. GRB020321: BeppoSAX/NFI Observations
  32. GRB020321: a faint BeppoSAX detection
  33. GRB 020317 : KISO Optical Observations
  34. BeppoSAX ALERT: GRB020321, the "Springtime Burst"
  35. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  36. GRB 020305: Optical Observations
  37. GRB020317, optical observations
  38. GRB 020317: Optical observations
  39. GRB 011121: Third HST Epoch
  40. GRB020305: Properties of the Candidate Optical Afterglow
  41. GRB 011121: HST Observations reveal an intermediate-time multicolor
  42. GRB011121, possible supernova association
  43. GRB011130 (XRF011130) Second Epoch Chandra Observations
  44. GRB020305: Subaru Optical Observations
  45. GRB 020305: Optical observations
  46. XRF/GRB 011030 Images
  47. XRF/GRB 011030: Detection of the Probable Host Galaxy
  48. GRB 020305: Candidate optical afterglow
  49. Type Ic SN2002bl (SN/GRB?) Radio Observations
  50. GRB020305: Optical Observations
  51. IPN triangulation of GRB020305 (HETE 1939)
  52. GRB020305 (=H1939): Localization of a GRB by HETE
  53. GRB 020305: Optical observations
  54. HST Imaging of the afterglow and host of GRB 011121
  55. GRB 010921: HST Observations
  56. IPN detection and localization of Cygnus X-1 flares
  57. GRB020127: Further VLA Observations of Possible Counterparts
  58. IPN detection of further SGR1900+14 activity
  59. SGR1900+14 activity
  60. IPN/HETE Detection of Bursts from SGR1900+14
  61. IPN Upper Limits to a GRB Associated With SN2002ap
  62. GRB020124 BVRI field photometry
  63. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  64. SN2002ap (SN/GRB?) Echelle spectra
  65. SN2002ap (SN/GRB?) optical spectrographic observations
  66. GRB020127 Optical Observations
  67. SN 2002ap (SN/GRB?)
  68. SN2002ap (SN/GRB?) UBVRI Field Photometry
  69. GRB020127: Chandra Observations and Prospective Counterparts
  70. pre-SN2002ap (SN/GRB?) imaging of M74
  71. SN 2002ap (hypernova / GRB ??): special list on VSNET
  72. Type Ib/c SN2002ap (SN/GRB?)
  73. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  74. GRB020124, optical observations
  75. GRB020127: Optical observations
  76. GRB 020127, I-band observations starting 3.14-hr after the event
  77. IPN detection of further activity from SGR1806-20
  78. IPN triangulation of GRB020127 (=H1902)
  79. GRB010921 Optical Observations
  80. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  81. GRB020124: Optical observations
  82. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  83. GRB020124: Optical observations
  84. GRB 020124: Optical observations
  85. GRB 020124 Optical Observations
  86. IPN triangulation of GRB020124 (HETE 1896)
  87. IPN observations of SGR1806-20
  88. GRB 020124: Optical afterglow
  89. GRB020124(=H1896): Localization of a Long GRB by HETE
  90. GRB optical counterpart candidate in GCN 1217 is M dwarf
  91. Possible optical counterpart to a GRB
  92. GRB011212, Optical Observations
  93. GRB 011211: Detection of the Probable Host Galaxy
  94. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  95. GRB 011211, spectrum and optical photometry
  96. GRB 011130: Optical Observations of X-ray and Radio Sources
  97. GRB 011130, Radio/X-ray Comparison
  98. GRB 011212: optical observation at Asiago
  99. GRB 011211: Evidence for an Optical Break
  100. GRB 011211: TNG Spectroscopic Observations

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