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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"

21206 results found.

  1. GRB991208, optical observations
  2. GRB 991208, Optical Observation
  3. GRB991208, optical observations
  4. GRB 991208 Optical Decay
  5. Optical Observations of GRB991105
  6. GRB991106: BeppoSAX/BATSE results
  7. GRB 991106, optical observations
  8. BeppoSAX NFI Observation of GRB991106
  9. GRB 991106, radio observations
  10. GRB991106: the first BeppoSAX short GRB detection?
  11. GRB 991106 Optical Observations
  12. GRB991106, optical observation at SAO-RAS
  13. GRB 991106, LOTIS Optical Observations
  14. GRB991105: SAX-GRBM/-WFC detection
  15. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  16. GRB ALERT: GRB991105
  17. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  18. GRB 991014, Optical Observations
  19. GRB 991014 - BeppoSAX NFI observations
  20. GRB 991014, radio observations
  21. GRB 991014, Optical Observations
  22. GRB 991014, optical observations
  23. Super-LOTIS optical observation of GRB991014
  24. Optical Observations of GRB990907
  25. GRB990907 and 990908
  26. GRB990806 BeppoSAX follow up
  27. GRB 990806 Optical observations
  28. Optical Observations of GRB990806
  29. GRB 990806, Optical Observations
  30. GRB 990806, optical observations
  31. GRB 990806, Optical Observations
  32. GRB 990712 Optical Observations
  33. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  34. GRB 990712
  35. Late-time HST/STIS Observations of GRB 990510
  36. Refined BeppoSAX-WFC position of GRB990712
  37. BeppoSAX NFI Observation of GRB990705
  38. BeppoSAX NFI Observation of GRB990705
  39. Updated Astrometry for the IR Counterpart of GRB990705
  40. GRB 990705, R-band observations
  41. Infrared and Optical Observations of GRB990705
  42. GRB 990705, radio observations
  43. GRB990704: SAX-NFI results summary
  44. GRB990704 radio and optical observations
  45. GRB990704
  46. GRB990704, optical observations
  47. GRB 990627, radio observations
  48. Late-time HST/STIS Observation of GRB 990123
  49. Optical Observations of GRB 990506
  50. GRB990527 Optical Observations
  51. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  52. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  53. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  54. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  55. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  56. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  57. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  58. radio observations of X-ray/GRB transient field
  59. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  60. Optical report on X-ray/GRB transient
  61. GRB 990510: optical linear polarization
  62. GRB 990510: optical observations
  63. GRB990510, VI observations
  64. GRB 990510: BATSE Observations
  65. GRB 990510: BeppoSAX/GRBM observations
  66. GRB 990510 optical observations
  67. GRB 990506 Radio Observations
  68. GRB 990123, optical monitoring
  69. GRB 990506, optical observations
  70. GRB 990506, Optical Observations
  71. GRB 990506 optical observations
  72. GRB 990506, optical observations
  73. GRB 990506, optical observations from +1 to +3 hours
  74. GRB 990506, optical observations
  75. GRB990506 observation plan
  76. GRB981220 VLBA observations
  77. GRB 990316 Optical Observations
  78. GRB 990316 optical observations
  79. GRB990316: simultaneous optical observation
  80. GRB990316 - Optical null results
  81. GRB 990123, Field Photometry
  82. GRB 990217 Optical Observations
  83. GRB 990217, radio observations
  84. BATSE Flight Anomaly
  85. GRB990123 observations
  86. GRB990123, Optical Observation
  87. GRB 990123: Discovery of the Probable Host Galaxy
  88. GRB 990123: Reduced HST Images
  89. GRB19990123 observations
  90. GRB 990123: BVRI standards in the field
  91. GRB981220, field photometry
  92. GRB990123, Optical observation
  93. GRB990123, 15-GHz limits
  94. GRB 990123: New Constraints on Possible Foreground Galaxies
  95. GRB990123 Optical Observations
  96. GRB990123, Probability of gravitational lensing
  97. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  98. GRB990123, Preliminary Lens Search Results
  99. GRB990123, Optical BVRI Observations
  100. GRB 990123: near-infrared observations.

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