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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"

42768 results found.

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

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