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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"

35956 results found.

  1. ASM GRB candidate 020406 refined error box
  2. GRB 020405: Moderate-resolution spectroscopy
  3. GRB020406(?), optical observations
  4. GRB020405: VLT optical observations
  5. Revised Photometry of the Optical Afterglow of GRB 020405
  6. GRB020405: OT observations
  7. GRB 020331: Candidate Optical Afterglow
  8. GRB 020405: Decay index
  9. Short RXTE/ASM transient 020406; may be a GRB
  10. GRB020405, Radio Observations
  11. Fading Optical Afterglow and Possible Host Galaxy of GRB 020405
  12. GRB 020405, U-band observations
  13. GRB 020405: Optical afterglow candidate
  14. IPN localization of GRB020405
  15. GRB011212: Optical Observations
  16. GRB 020331: NIR Observations
  17. GRB 020331: NIR Observations
  18. GRB020331 NIR observation at KPNO (re-submission)
  19. GRB02033 NIR observation at KPNO
  20. GRB020331 field photometry
  21. GRB 020331 Optical Observations
  22. GRB 020331, NIR observations
  23. GRB 020331: Optical observations
  24. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  25. GRB 020321: Infrared observations
  26. GRB 020322: BeppoSAX observations of the X-ray afterglow
  27. SN 2002ap - peak brightness date (SN/GRB?)
  28. GRB 020322, Radio observations
  29. Near-Infrared Observations of GRB020322 at TIRGO
  30. GRB 020321, Radio Observations
  31. GRB 020322: Optical Observations
  32. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  33. GRB 020321: Optical observations
  34. GRB020317 BVRI field photometry
  35. GRB011211 revised BVRI field photometry
  36. GRB020305 BVRI field photometry
  37. GRB020322 BVRI field photometry
  38. GRB 020322 optical observations
  39. GRB 020322 optical observation
  40. GRB020317 : Near IR Observations from Mt Abu Observatory
  41. GRB 020322: Optical Sources and Improved Astrometry
  42. GRB020322, optical observations
  43. GRB 020322: Optical candidate
  44. GRB020322: BeppoSAX/NFI Observations
  45. Bepposax GRB020322 The second springtime BSAX GRB
  46. GRB 020321: Optical observations
  47. GRB 011121: Fourth Epoch of HST Imaging
  48. GRB020317: optical observations
  49. GRB020321 optical observations
  50. GRB020321: BeppoSAX/NFI Observations
  51. GRB020321: a faint BeppoSAX detection
  52. GRB 020317 : KISO Optical Observations
  53. BeppoSAX ALERT: GRB020321, the "Springtime Burst"
  54. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  55. GRB 020305: Optical Observations
  56. GRB020317, optical observations
  57. GRB 020317: Optical observations
  58. GRB 011121: Third HST Epoch
  59. GRB020305: Properties of the Candidate Optical Afterglow
  60. GRB 011121: HST Observations reveal an intermediate-time multicolor
  61. GRB011121, possible supernova association
  62. GRB011130 (XRF011130) Second Epoch Chandra Observations
  63. GRB020305: Subaru Optical Observations
  64. GRB 020305: Optical observations
  65. XRF/GRB 011030 Images
  66. XRF/GRB 011030: Detection of the Probable Host Galaxy
  67. GRB 020305: Candidate optical afterglow
  68. Type Ic SN2002bl (SN/GRB?) Radio Observations
  69. GRB020305: Optical Observations
  70. IPN triangulation of GRB020305 (HETE 1939)
  71. GRB020305 (=H1939): Localization of a GRB by HETE
  72. GRB 020305: Optical observations
  73. HST Imaging of the afterglow and host of GRB 011121
  74. GRB 010921: HST Observations
  75. IPN detection and localization of Cygnus X-1 flares
  76. GRB020127: Further VLA Observations of Possible Counterparts
  77. IPN detection of further SGR1900+14 activity
  78. SGR1900+14 activity
  79. IPN/HETE Detection of Bursts from SGR1900+14
  80. IPN Upper Limits to a GRB Associated With SN2002ap
  81. GRB020124 BVRI field photometry
  82. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  83. SN2002ap (SN/GRB?) Echelle spectra
  84. SN2002ap (SN/GRB?) optical spectrographic observations
  85. GRB020127 Optical Observations
  86. SN 2002ap (SN/GRB?)
  87. SN2002ap (SN/GRB?) UBVRI Field Photometry
  88. GRB020127: Chandra Observations and Prospective Counterparts
  89. pre-SN2002ap (SN/GRB?) imaging of M74
  90. SN 2002ap (hypernova / GRB ??): special list on VSNET
  91. Type Ib/c SN2002ap (SN/GRB?)
  92. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  93. GRB020124, optical observations
  94. GRB020127: Optical observations
  95. GRB 020127, I-band observations starting 3.14-hr after the event
  96. IPN detection of further activity from SGR1806-20
  97. IPN triangulation of GRB020127 (=H1902)
  98. GRB010921 Optical Observations
  99. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  100. GRB020124: Optical observations

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