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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"

35344 results found.

  1. GRB 020405: Optical afterglow candidate
  2. IPN localization of GRB020405
  3. GRB011212: Optical Observations
  4. GRB 020331: NIR Observations
  5. GRB 020331: NIR Observations
  6. GRB020331 NIR observation at KPNO (re-submission)
  7. GRB02033 NIR observation at KPNO
  8. GRB020331 field photometry
  9. GRB 020331 Optical Observations
  10. GRB 020331, NIR observations
  11. GRB 020331: Optical observations
  12. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  13. GRB 020321: Infrared observations
  14. GRB 020322: BeppoSAX observations of the X-ray afterglow
  15. SN 2002ap - peak brightness date (SN/GRB?)
  16. GRB 020322, Radio observations
  17. Near-Infrared Observations of GRB020322 at TIRGO
  18. GRB 020321, Radio Observations
  19. GRB 020322: Optical Observations
  20. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  21. GRB 020321: Optical observations
  22. GRB020317 BVRI field photometry
  23. GRB011211 revised BVRI field photometry
  24. GRB020305 BVRI field photometry
  25. GRB020322 BVRI field photometry
  26. GRB 020322 optical observations
  27. GRB 020322 optical observation
  28. GRB020317 : Near IR Observations from Mt Abu Observatory
  29. GRB 020322: Optical Sources and Improved Astrometry
  30. GRB020322, optical observations
  31. GRB 020322: Optical candidate
  32. GRB020322: BeppoSAX/NFI Observations
  33. Bepposax GRB020322 The second springtime BSAX GRB
  34. GRB 020321: Optical observations
  35. GRB 011121: Fourth Epoch of HST Imaging
  36. GRB020317: optical observations
  37. GRB020321 optical observations
  38. GRB020321: BeppoSAX/NFI Observations
  39. GRB020321: a faint BeppoSAX detection
  40. GRB 020317 : KISO Optical Observations
  41. BeppoSAX ALERT: GRB020321, the "Springtime Burst"
  42. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  43. GRB 020305: Optical Observations
  44. GRB020317, optical observations
  45. GRB 020317: Optical observations
  46. GRB 011121: Third HST Epoch
  47. GRB020305: Properties of the Candidate Optical Afterglow
  48. GRB 011121: HST Observations reveal an intermediate-time multicolor
  49. GRB011121, possible supernova association
  50. GRB011130 (XRF011130) Second Epoch Chandra Observations
  51. GRB020305: Subaru Optical Observations
  52. GRB 020305: Optical observations
  53. XRF/GRB 011030 Images
  54. XRF/GRB 011030: Detection of the Probable Host Galaxy
  55. GRB 020305: Candidate optical afterglow
  56. Type Ic SN2002bl (SN/GRB?) Radio Observations
  57. GRB020305: Optical Observations
  58. IPN triangulation of GRB020305 (HETE 1939)
  59. GRB020305 (=H1939): Localization of a GRB by HETE
  60. GRB 020305: Optical observations
  61. HST Imaging of the afterglow and host of GRB 011121
  62. GRB 010921: HST Observations
  63. IPN detection and localization of Cygnus X-1 flares
  64. GRB020127: Further VLA Observations of Possible Counterparts
  65. IPN detection of further SGR1900+14 activity
  66. SGR1900+14 activity
  67. IPN/HETE Detection of Bursts from SGR1900+14
  68. IPN Upper Limits to a GRB Associated With SN2002ap
  69. GRB020124 BVRI field photometry
  70. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  71. SN2002ap (SN/GRB?) Echelle spectra
  72. SN2002ap (SN/GRB?) optical spectrographic observations
  73. GRB020127 Optical Observations
  74. SN 2002ap (SN/GRB?)
  75. SN2002ap (SN/GRB?) UBVRI Field Photometry
  76. GRB020127: Chandra Observations and Prospective Counterparts
  77. pre-SN2002ap (SN/GRB?) imaging of M74
  78. SN 2002ap (hypernova / GRB ??): special list on VSNET
  79. Type Ib/c SN2002ap (SN/GRB?)
  80. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  81. GRB020124, optical observations
  82. GRB020127: Optical observations
  83. GRB 020127, I-band observations starting 3.14-hr after the event
  84. IPN detection of further activity from SGR1806-20
  85. IPN triangulation of GRB020127 (=H1902)
  86. GRB010921 Optical Observations
  87. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  88. GRB020124: Optical observations
  89. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  90. GRB020124: Optical observations
  91. GRB 020124: Optical observations
  92. GRB 020124 Optical Observations
  93. IPN triangulation of GRB020124 (HETE 1896)
  94. IPN observations of SGR1806-20
  95. GRB 020124: Optical afterglow
  96. GRB020124(=H1896): Localization of a Long GRB by HETE
  97. GRB optical counterpart candidate in GCN 1217 is M dwarf
  98. Possible optical counterpart to a GRB
  99. GRB011212, Optical Observations
  100. GRB 011211: Detection of the Probable Host Galaxy

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