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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"

28057 results found.

  1. GRB 991208 Keck Spectroscopy
  2. GRB 991208 Infrared Detection
  3. GRB991216
  4. GRB 991216--Summary of RXTE Observations
  5. GRB 991216 Optical Observations
  6. GRB 991216, optical observations
  7. GRB 991208 SAO-RAS Spectroscopy
  8. SAX J2303.2+0015: an x-ray/GRB?
  9. GRB 991216, Optical Transient
  10. GRB991216 ('Beethoven Burst') B, R, and K Observations
  11. GRB991216, infrared observations
  12. GRB 991208 optical observations
  13. GRB 991216 Optical Observation
  14. GRB 991216: Extremely bright BATSE burst
  15. R-band Observations of GRB991208 at TNG
  16. GRB991208, optical observations
  17. GRB 991208, Optical Observation
  18. GRB991208, optical observations
  19. GRB 991208 optical observations
  20. Optical Observations of GRB991105
  21. GRB991106: BeppoSAX/BATSE results
  22. GRB991106, near-infrared observations
  23. BeppoSAX NFI Observation of GRB991106
  24. GRB 991106, radio observations
  25. GRB991106: the first BeppoSAX short GRB detection?
  26. GRB 991105: BATSE Observations
  27. GRB 991106 Optical Observations
  28. GRB991106, optical observation at SAO-RAS
  29. GRB 991106, LOTIS Optical Observations
  30. GRB991105: SAX-GRBM/-WFC detection
  31. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  32. GRB 991014, Optical Observations
  33. GRB 991014 - BeppoSAX NFI observations
  34. GRB 991014, radio observations
  35. GRB 991014, Optical Observations
  36. GRB 991014, optical observations
  37. GRB 990915 optical observations
  38. Optical Observations of GRB990907
  39. GRB990907: BeppoSAX follow up and X-ray afterglow
  40. GRB990907 and 990908
  41. GRB 990712 Late Optical Decay and Host Galaxy
  42. GRB990806 BeppoSAX follow up
  43. GRB990806: BATSE Observations
  44. GRB 990806 Optical observations
  45. GRB 990806, Optical Observations
  46. GRB 990806, optical observations
  47. GRB 990806, Optical Observations
  48. GRB990806 UBVRIJHK observations
  49. GRB 990712 Optical Observations
  50. GRB 990712
  51. Late-time HST/STIS Observations of GRB 990510
  52. BeppoSAX NFI Observation of GRB990705
  53. BeppoSAX NFI Observation of GRB990705
  54. GRB 990705, R-band observations
  55. Infrared and Optical Observations of GRB990705
  56. GRB990704: SAX-NFI results summary
  57. GRB990704 radio and optical observations
  58. GRB990704
  59. GRB990704, optical observations
  60. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  61. Optical Observations of GRB990627
  62. BeppoSAX: GRB990625
  63. Late-time HST/STIS Observation of GRB 990123
  64. Optical Observations of GRB 990506
  65. GRB990527 Optical Observations
  66. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  67. Late Afterglows of GRBs 990510, 990123
  68. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  69. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  70. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  71. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  72. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  73. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  74. radio observations of X-ray/GRB transient field
  75. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  76. Optical report on X-ray/GRB transient
  77. radio detection of X-ray/GRB transient
  78. BeppoSAX: A new fast X-ray transient
  79. GRB 990510: optical observations
  80. GRB 990510: optical linear polarization
  81. GRB 990510: optical observations
  82. GRB990510: X-ray afterglow
  83. GRB 990510: Broad Band Break
  84. GRB 990510: BATSE Observations
  85. GRB 990510: BeppoSAX/GRBM observations
  86. GRB990510 optical observations
  87. GRB 990510 optical observations
  88. GRB 990506 Radio Observations
  89. GRB 990123, optical monitoring
  90. GRB 990506: BATSE Observations
  91. GRB 990506, optical observations
  92. GRB 990506, Optical Observations
  93. GRB 990506 optical observations
  94. GRB 990506, optical observations
  95. GRB 990506, armchair astronomy
  96. GRB 990506, optical observations from +1 to +3 hours
  97. GRB 990506, optical observations
  98. GRB990506 observation plan
  99. IPN localization for GRB990506
  100. GRB990323 PRECISE IPN POSITION

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