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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"

42560 results found.

  1. Refined IPN localization of GRB991216
  2. GRB 991216 Radio Observations
  3. GRB 991217
  4. GRB 991208 Keck Spectroscopy
  5. GRB 991208 Infrared Detection
  6. GRB991216
  7. GRB 991216--Summary of RXTE Observations
  8. GRB 991216 Optical Observations
  9. GRB 991216, optical observations
  10. GRB 991208 SAO-RAS Spectroscopy
  11. SAX J2303.2+0015: an x-ray/GRB?
  12. GRB 991216, Optical Transient
  13. GRB 991216, Optical Afterglow
  14. GRB991216 ('Beethoven Burst') B, R, and K Observations
  15. GRB 991216: Comparison with DPOSS images
  16. GRB991216, infrared observations
  17. GRB991216 Optical Observations
  18. GRB 991208 optical observations
  19. Lowell/Perkins observation of GRB 991216
  20. GRB 991216 Optical Observation
  21. GRB 991208 Keck Spectroscopy
  22. GRB 991216: Extremely bright BATSE burst
  23. R-band Observations of GRB991208 at TNG
  24. GRB991208, optical observations
  25. GRB 991208 Keck Spectroscopy
  26. GRB991208 - millimeter detection
  27. GRB 991208, Optical Observation
  28. GRB991208, optical observations
  29. GRB 991208 - OVRO detection
  30. GRB 991208 Optical Decay
  31. GRB 991208 optical observations
  32. GRB 991208 optical observations
  33. GRB 991208: Radio Observations
  34. IPN localization of GRB991208
  35. Optical Observations of GRB991105
  36. GRB991106: BeppoSAX/BATSE results
  37. GRB 991106, optical observations
  38. GRB991106, near-infrared observations
  39. BeppoSAX NFI Observation of GRB991106
  40. GRB 991106, radio observations
  41. GRB991106: the first BeppoSAX short GRB detection?
  42. GRB 991105: BATSE Observations
  43. IPN localization of GRB991105
  44. GRB 991106 Optical Observations
  45. GRB 991105, optical observations
  46. GRB991106, optical observation at SAO-RAS
  47. GRB 991106, LOTIS Optical Observations
  48. GRB 991106, optical observations
  49. BeppoSAX GRB Alert: GRB991106
  50. GRB991105: SAX-GRBM/-WFC detection
  51. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  52. GRB ALERT: GRB991105
  53. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  54. GRB 991014, Optical Observations
  55. GRB 991014 - BeppoSAX NFI observations
  56. GRB 991014, Optical Observations
  57. GRB 991014, radio observations
  58. GRB991014 BATSE Observations
  59. GRB 991014, Optical Observations
  60. GRB 991014, optical observations
  61. IPN localization of GRB991014 - CORRECTION
  62. IPN localization of GRB991014
  63. BeppoSAX ALERT: GRB991014
  64. GRB 990915 optical observations
  65. GRB 990907 optical observations
  66. Optical Observations of GRB990907
  67. IPN error box for GRB990915 (=BATSE 7766)
  68. IPN localization of BATSE #7766 (GRB990915)
  69. GRB990907: BeppoSAX follow up and X-ray afterglow
  70. GRB990907 and 990908
  71. IPN localization of GRB990907
  72. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  73. GRB990907: refined WFC position
  74. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  75. GRB 990712 Late Optical Decay and Host Galaxy
  76. GRB 990712, Optical Observation
  77. GRB990806 BeppoSAX follow up
  78. GRB990806: BATSE Observations
  79. GRB 990806 Optical observations
  80. Optical Observations of GRB990806
  81. GRB 990806, Optical Observations
  82. GRB 990806, optical observations
  83. GRB 990806, Optical Observations
  84. GRB990806 UBVRIJHK observations
  85. GRB990806: possible X-ray afterglow, BeppoSAX
  86. BeppoSAX ALERT GRB990806: Summer GRB
  87. GRB 990712 Optical Observations
  88. GRB990705: No Evidence for Neutrino Signal
  89. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  90. VLT spectrum of GRB990712
  91. GRB 990712
  92. Late-time HST/STIS Observations of GRB 990510
  93. Refined BeppoSAX-WFC position of GRB990712
  94. BeppoSAX NFI Observation of GRB990705
  95. BeppoSAX NFI Observation of GRB990705
  96. Updated Astrometry for the IR Counterpart of GRB990705
  97. GRB 990705, R-band observations
  98. Updated IPN localization of GRB990705
  99. IPN localization of GRB990704
  100. IPN localization of GRB990705

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