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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"

41642 results found.

  1. R-band Observations of GRB991208 at TNG
  2. GRB991208, optical observations
  3. GRB 991208 Keck Spectroscopy
  4. GRB991208 - millimeter detection
  5. GRB 991208, Optical Observation
  6. GRB991208, optical observations
  7. GRB 991208 - OVRO detection
  8. GRB 991208 Optical Decay
  9. GRB 991208 optical observations
  10. GRB 991208 optical observations
  11. GRB 991208: Radio Observations
  12. IPN localization of GRB991208
  13. Optical Observations of GRB991105
  14. GRB991106: BeppoSAX/BATSE results
  15. GRB 991106, optical observations
  16. GRB991106, near-infrared observations
  17. BeppoSAX NFI Observation of GRB991106
  18. GRB991106: the first BeppoSAX short GRB detection?
  19. GRB 991105: BATSE Observations
  20. IPN localization of GRB991105
  21. GRB 991106 Optical Observations
  22. GRB 991105, optical observations
  23. GRB 991106, LOTIS Optical Observations
  24. GRB 991106, optical observations
  25. Revised BeppoSAX WFC position of GRB991105
  26. GRB991105: SAX-GRBM/-WFC detection
  27. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  28. GRB ALERT: GRB991105
  29. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  30. GRB 991014, Optical Observations
  31. GRB 991014 - BeppoSAX NFI observations
  32. GRB 991014, Optical Observations
  33. GRB 991014, radio observations
  34. GRB991014 BATSE Observations
  35. GRB 991014, Optical Observations
  36. GRB 991014, optical observations
  37. Super-LOTIS optical observation of GRB991014
  38. IPN/NFI error box for GRB991014
  39. IPN localization of GRB991014 - CORRECTION
  40. IPN localization of GRB991014
  41. BeppoSAX ALERT: GRB991014
  42. GRB 990915 optical observations
  43. GRB 990907 optical observations
  44. Optical Observations of GRB990907
  45. IPN error box for GRB990915 (=BATSE 7766)
  46. IPN localization of BATSE #7766 (GRB990915)
  47. GRB990907: BeppoSAX follow up and X-ray afterglow
  48. GRB990907 and 990908
  49. IPN localization of GRB990907
  50. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  51. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  52. GRB 990712 Late Optical Decay and Host Galaxy
  53. GRB 990712, Optical Observation
  54. GRB990806 BeppoSAX follow up
  55. GRB990806: BATSE Observations
  56. GRB 990806 Optical observations
  57. Optical Observations of GRB990806
  58. GRB 990806, Optical Observations
  59. GRB 990806, optical observations
  60. GRB 990806, Optical Observations
  61. GRB990806 UBVRIJHK observations
  62. GRB990806: possible X-ray afterglow, BeppoSAX
  63. BeppoSAX ALERT GRB990806: Summer GRB
  64. GRB990705: No Evidence for Neutrino Signal
  65. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  66. VLT spectrum of GRB990712
  67. GRB 990712
  68. Late-time HST/STIS Observations of GRB 990510
  69. Refined BeppoSAX-WFC position of GRB990712
  70. BeppoSAX NFI Observation of GRB990705
  71. BeppoSAX NFI Observation of GRB990705
  72. Updated Astrometry for the IR Counterpart of GRB990705
  73. GRB 990705, R-band observations
  74. Updated IPN localization of GRB990705
  75. IPN localization of GRB990704
  76. IPN localization of GRB990705
  77. Infrared and Optical Observations of GRB990705
  78. GRB 990705, radio observations
  79. GRB990704: SAX-NFI results summary
  80. GRB990704 radio and optical observations
  81. BeppoSAX GRB990705: possible X-ray afterglow
  82. GRB 990704 X-ray Observations
  83. GRB 990704 Optical Observations
  84. GRB 990704, optical observations
  85. GRB990704
  86. GRB990705: Intriguing Positional Coincidences
  87. GRB990704
  88. GRB990704, optical observations
  89. Identification of a possible optical counterpart for GRB990704
  90. GRB990704
  91. Refined BeppoSAX-WFC position of GRB990704
  92. GRB990704: BeppoSAX detection
  93. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  94. Optical Observations of GRB990627
  95. GRB 990627, radio observations
  96. GRB990627: BeppoSAX-WFC final location
  97. BeppoSAX: GRB990625
  98. Late-time HST/STIS Observation of GRB 990123
  99. GRB 990506 - clarification to GCN 352
  100. GRB 990506 - Optical Observations

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