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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"

24658 results found.

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

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