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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"

26361 results found.

  1. IR observations of GRB991216
  2. GRB 991217 (SAX J2303.2+0015) Optical observations
  3. GRB991216 Optical and infrared observations of Beethoven Burst
  4. GRB 991216 Radio Observations
  5. GRB 991208 Keck Spectroscopy
  6. GRB 991208 Infrared Detection
  7. GRB991216
  8. GRB 991216--Summary of RXTE Observations
  9. GRB 991216 Optical Observations
  10. GRB 991216, optical observations
  11. GRB 991208 SAO-RAS Spectroscopy
  12. SAX J2303.2+0015: an x-ray/GRB?
  13. GRB 991216, Optical Transient
  14. GRB991216 ('Beethoven Burst') B, R, and K Observations
  15. GRB991216, infrared observations
  16. GRB 991208 optical observations
  17. GRB 991216 Optical Observation
  18. GRB 991216: Extremely bright BATSE burst
  19. R-band Observations of GRB991208 at TNG
  20. GRB991208, optical observations
  21. GRB 991208, Optical Observation
  22. GRB991208, optical observations
  23. GRB 991208 optical observations
  24. Optical Observations of GRB991105
  25. GRB991106: BeppoSAX/BATSE results
  26. GRB991106, near-infrared observations
  27. BeppoSAX NFI Observation of GRB991106
  28. GRB 991106, radio observations
  29. GRB991106: the first BeppoSAX short GRB detection?
  30. GRB 991105: BATSE Observations
  31. GRB 991106 Optical Observations
  32. GRB991106, optical observation at SAO-RAS
  33. GRB 991106, LOTIS Optical Observations
  34. GRB991105: SAX-GRBM/-WFC detection
  35. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  36. GRB 991014, Optical Observations
  37. GRB 991014 - BeppoSAX NFI observations
  38. GRB 991014, radio observations
  39. GRB 991014, Optical Observations
  40. GRB 991014, optical observations
  41. GRB 990915 optical observations
  42. Optical Observations of GRB990907
  43. GRB990907: BeppoSAX follow up and X-ray afterglow
  44. GRB990907 and 990908
  45. GRB 990712 Late Optical Decay and Host Galaxy
  46. GRB990806 BeppoSAX follow up
  47. GRB990806: BATSE Observations
  48. GRB 990806 Optical observations
  49. GRB 990806, Optical Observations
  50. GRB 990806, optical observations
  51. GRB 990806, Optical Observations
  52. GRB990806 UBVRIJHK observations
  53. GRB 990712 Optical Observations
  54. GRB 990712
  55. Late-time HST/STIS Observations of GRB 990510
  56. BeppoSAX NFI Observation of GRB990705
  57. BeppoSAX NFI Observation of GRB990705
  58. GRB 990705, R-band observations
  59. Infrared and Optical Observations of GRB990705
  60. GRB990704: SAX-NFI results summary
  61. GRB990704 radio and optical observations
  62. GRB990704
  63. GRB990704, optical observations
  64. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  65. Optical Observations of GRB990627
  66. BeppoSAX: GRB990625
  67. Late-time HST/STIS Observation of GRB 990123
  68. Optical Observations of GRB 990506
  69. GRB990527 Optical Observations
  70. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  71. Late Afterglows of GRBs 990510, 990123
  72. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  73. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  74. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  75. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  76. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  77. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  78. radio observations of X-ray/GRB transient field
  79. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  80. Optical report on X-ray/GRB transient
  81. radio detection of X-ray/GRB transient
  82. BeppoSAX: A new fast X-ray transient
  83. GRB 990510: optical observations
  84. GRB 990510: optical linear polarization
  85. GRB 990510: optical observations
  86. GRB990510: X-ray afterglow
  87. GRB 990510: Broad Band Break
  88. GRB 990510: BATSE Observations
  89. GRB 990510: BeppoSAX/GRBM observations
  90. GRB990510 optical observations
  91. GRB 990510 optical observations
  92. GRB 990506 Radio Observations
  93. GRB 990123, optical monitoring
  94. GRB 990506: BATSE Observations
  95. GRB 990506, optical observations
  96. GRB 990506, Optical Observations
  97. GRB 990506 optical observations
  98. GRB 990506, optical observations
  99. GRB 990506, armchair astronomy
  100. GRB 990506, optical observations from +1 to +3 hours

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