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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"

32858 results found.

  1. GRB020406(?), optical observations
  2. GRB020405: VLT optical observations
  3. Revised Photometry of the Optical Afterglow of GRB 020405
  4. GRB020405: OT observations
  5. GRB 020331: Candidate Optical Afterglow
  6. GRB 020405: Decay index
  7. Short RXTE/ASM transient 020406; may be a GRB
  8. GRB020405, Radio Observations
  9. Fading Optical Afterglow and Possible Host Galaxy of GRB 020405
  10. GRB 020405, U-band observations
  11. GRB 020405: Optical afterglow candidate
  12. IPN localization of GRB020405
  13. GRB011212: Optical Observations
  14. GRB 020331: NIR Observations
  15. GRB 020331: NIR Observations
  16. GRB020331 NIR observation at KPNO (re-submission)
  17. GRB02033 NIR observation at KPNO
  18. GRB020331 field photometry
  19. GRB 020331 Optical Observations
  20. GRB 020331, NIR observations
  21. GRB 020331: Optical observations
  22. GRB020331(=H1963): The "Easter" Burst Detected by HETE
  23. GRB 020321: Infrared observations
  24. GRB 020322: BeppoSAX observations of the X-ray afterglow
  25. SN 2002ap - peak brightness date (SN/GRB?)
  26. GRB 020322, Radio observations
  27. Near-Infrared Observations of GRB020322 at TIRGO
  28. GRB 020321, Radio Observations
  29. GRB 020322: Optical Observations
  30. GRB020127: Proposed Host Galaxy Detection and Identification of Afterglow
  31. GRB 020321: Optical observations
  32. GRB020317 BVRI field photometry
  33. GRB011211 revised BVRI field photometry
  34. GRB020305 BVRI field photometry
  35. GRB020322 BVRI field photometry
  36. GRB 020322 optical observations
  37. GRB 020322 optical observation
  38. GRB020317 : Near IR Observations from Mt Abu Observatory
  39. GRB 020322: Optical Sources and Improved Astrometry
  40. GRB020322, optical observations
  41. GRB 020322: Optical candidate
  42. GRB020322: BeppoSAX/NFI Observations
  43. Bepposax GRB020322 The second springtime BSAX GRB
  44. GRB 020321: Optical observations
  45. GRB 011121: Fourth Epoch of HST Imaging
  46. GRB020317: optical observations
  47. GRB020321 optical observations
  48. GRB020321: BeppoSAX/NFI Observations
  49. GRB020321: a faint BeppoSAX detection
  50. GRB 020317 : KISO Optical Observations
  51. BeppoSAX ALERT: GRB020321, the "Springtime Burst"
  52. GRB020317 (=H1959): Localization by HETE of a Low Fluence GRB
  53. GRB 020305: Optical Observations
  54. GRB020317, optical observations
  55. GRB 020317: Optical observations
  56. GRB 011121: Third HST Epoch
  57. GRB020305: Properties of the Candidate Optical Afterglow
  58. GRB 011121: HST Observations reveal an intermediate-time multicolor
  59. GRB011121, possible supernova association
  60. GRB011130 (XRF011130) Second Epoch Chandra Observations
  61. GRB020305: Subaru Optical Observations
  62. GRB 020305: Optical observations
  63. XRF/GRB 011030 Images
  64. XRF/GRB 011030: Detection of the Probable Host Galaxy
  65. GRB 020305: Candidate optical afterglow
  66. Type Ic SN2002bl (SN/GRB?) Radio Observations
  67. GRB020305: Optical Observations
  68. IPN triangulation of GRB020305 (HETE 1939)
  69. GRB020305 (=H1939): Localization of a GRB by HETE
  70. GRB 020305: Optical observations
  71. HST Imaging of the afterglow and host of GRB 011121
  72. GRB 010921: HST Observations
  73. IPN detection and localization of Cygnus X-1 flares
  74. GRB020127: Further VLA Observations of Possible Counterparts
  75. IPN detection of further SGR1900+14 activity
  76. SGR1900+14 activity
  77. IPN/HETE Detection of Bursts from SGR1900+14
  78. IPN Upper Limits to a GRB Associated With SN2002ap
  79. GRB020124 BVRI field photometry
  80. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  81. SN2002ap (SN/GRB?) Echelle spectra
  82. SN2002ap (SN/GRB?) optical spectrographic observations
  83. GRB020127 Optical Observations
  84. SN 2002ap (SN/GRB?)
  85. SN2002ap (SN/GRB?) UBVRI Field Photometry
  86. GRB020127: Chandra Observations and Prospective Counterparts
  87. pre-SN2002ap (SN/GRB?) imaging of M74
  88. SN 2002ap (hypernova / GRB ??): special list on VSNET
  89. Type Ib/c SN2002ap (SN/GRB?)
  90. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  91. GRB020124, optical observations
  92. GRB020127: Optical observations
  93. GRB 020127, I-band observations starting 3.14-hr after the event
  94. IPN detection of further activity from SGR1806-20
  95. IPN triangulation of GRB020127 (=H1902)
  96. GRB010921 Optical Observations
  97. GRB020127(=H1902): Localization of a Double-Peaked GRB by HETE
  98. GRB020124: Optical observations
  99. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  100. GRB020124: Optical observations

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