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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"

25040 results found.

  1. GRB991208, optical observations
  2. GRB 991208 optical observations
  3. Optical Observations of GRB991105
  4. GRB991106: BeppoSAX/BATSE results
  5. GRB991106, near-infrared observations
  6. BeppoSAX NFI Observation of GRB991106
  7. GRB 991106, radio observations
  8. GRB991106: the first BeppoSAX short GRB detection?
  9. GRB 991105: BATSE Observations
  10. GRB 991106 Optical Observations
  11. GRB991106, optical observation at SAO-RAS
  12. GRB 991106, LOTIS Optical Observations
  13. GRB991105: SAX-GRBM/-WFC detection
  14. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  15. GRB 991014, Optical Observations
  16. GRB 991014 - BeppoSAX NFI observations
  17. GRB 991014, radio observations
  18. GRB 991014, Optical Observations
  19. GRB 991014, optical observations
  20. GRB 990915 optical observations
  21. Optical Observations of GRB990907
  22. GRB990907: BeppoSAX follow up and X-ray afterglow
  23. GRB990907 and 990908
  24. GRB 990712 Late Optical Decay and Host Galaxy
  25. GRB990806 BeppoSAX follow up
  26. GRB990806: BATSE Observations
  27. GRB 990806 Optical observations
  28. GRB 990806, Optical Observations
  29. GRB 990806, optical observations
  30. GRB 990806, Optical Observations
  31. GRB990806 UBVRIJHK observations
  32. GRB 990712 Optical Observations
  33. GRB 990712
  34. Late-time HST/STIS Observations of GRB 990510
  35. BeppoSAX NFI Observation of GRB990705
  36. BeppoSAX NFI Observation of GRB990705
  37. GRB 990705, R-band observations
  38. Infrared and Optical Observations of GRB990705
  39. GRB990704: SAX-NFI results summary
  40. GRB990704 radio and optical observations
  41. GRB990704
  42. GRB990704, optical observations
  43. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  44. Optical Observations of GRB990627
  45. BeppoSAX: GRB990625
  46. Late-time HST/STIS Observation of GRB 990123
  47. Optical Observations of GRB 990506
  48. GRB990527 Optical Observations
  49. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  50. Late Afterglows of GRBs 990510, 990123
  51. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  52. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  53. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  54. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  55. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  56. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  57. radio observations of X-ray/GRB transient field
  58. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  59. Optical report on X-ray/GRB transient
  60. radio detection of X-ray/GRB transient
  61. BeppoSAX: A new fast X-ray transient
  62. GRB 990510: optical observations
  63. GRB 990510: optical linear polarization
  64. GRB 990510: optical observations
  65. GRB990510: X-ray afterglow
  66. GRB 990510: Broad Band Break
  67. GRB 990510: BATSE Observations
  68. GRB 990510: BeppoSAX/GRBM observations
  69. GRB990510 optical observations
  70. GRB 990510 optical observations
  71. GRB 990506 Radio Observations
  72. GRB 990123, optical monitoring
  73. GRB 990506: BATSE Observations
  74. GRB 990506, optical observations
  75. GRB 990506, Optical Observations
  76. GRB 990506 optical observations
  77. GRB 990506, optical observations
  78. GRB 990506, armchair astronomy
  79. GRB 990506, optical observations from +1 to +3 hours
  80. GRB 990506, optical observations
  81. GRB990506 observation plan
  82. IPN localization for GRB990506
  83. GRB990323 PRECISE IPN POSITION
  84. GRB 990316 Optical Observations
  85. GRB 990316 optical observations
  86. GRB990316: simultaneous optical observation
  87. GRB990316 - Optical null results
  88. GRB990308 not a new SGR
  89. GRB 990308a and GRB 990308b
  90. GRB990308, Possible new SGR~0209+70
  91. GRB 990123, Field Photometry
  92. GRB 990217 Optical Observations
  93. BATSE Flight Anomaly
  94. GRB990217: BeppoSAX/GRBM data
  95. GRB990123 observations
  96. GRB990217 Optical observation
  97. GRB990123, Optical Observation
  98. GRB 990123: Discovery of the Probable Host Galaxy
  99. GRB 990123: Reduced HST Images
  100. GRB19990123 observations

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