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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"

24870 results found.

  1. GRB 991216: Detection of the Host and/or Absorber Galaxy
  2. IPN localization of GRB991226
  3. GRB 991216 RXTE ASM Observations
  4. GRB 991216: Updated BATSE parameters
  5. GRB 991217 (SAX J2303.2+0015) Optical observations
  6. Chandra observation of the X-ray afterglow of GRB991216
  7. GRB 991216, optical observations
  8. GRB 991216 Optical spectroscopy/imaging
  9. SAX J2303.2+0015 Optical observations
  10. IR observations of GRB991216
  11. GRB 991217 (SAX J2303.2+0015) Optical observations
  12. GRB991216 Optical and infrared observations of Beethoven Burst
  13. GRB 991216 Radio Observations
  14. GRB 991208 Keck Spectroscopy
  15. GRB 991208 Infrared Detection
  16. GRB991216
  17. GRB 991216--Summary of RXTE Observations
  18. GRB 991216 Optical Observations
  19. GRB 991216, optical observations
  20. GRB 991208 SAO-RAS Spectroscopy
  21. SAX J2303.2+0015: an x-ray/GRB?
  22. GRB 991216, Optical Transient
  23. GRB991216 ('Beethoven Burst') B, R, and K Observations
  24. GRB991216, infrared observations
  25. GRB 991208 optical observations
  26. GRB 991216 Optical Observation
  27. GRB 991216: Extremely bright BATSE burst
  28. R-band Observations of GRB991208 at TNG
  29. GRB991208, optical observations
  30. GRB 991208, Optical Observation
  31. GRB991208, optical observations
  32. GRB 991208 optical observations
  33. Optical Observations of GRB991105
  34. GRB991106: BeppoSAX/BATSE results
  35. GRB991106, near-infrared observations
  36. BeppoSAX NFI Observation of GRB991106
  37. GRB 991106, radio observations
  38. GRB991106: the first BeppoSAX short GRB detection?
  39. GRB 991105: BATSE Observations
  40. GRB 991106 Optical Observations
  41. GRB991106, optical observation at SAO-RAS
  42. GRB 991106, LOTIS Optical Observations
  43. GRB991105: SAX-GRBM/-WFC detection
  44. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  45. GRB 991014, Optical Observations
  46. GRB 991014 - BeppoSAX NFI observations
  47. GRB 991014, radio observations
  48. GRB 991014, Optical Observations
  49. GRB 991014, optical observations
  50. GRB 990915 optical observations
  51. Optical Observations of GRB990907
  52. GRB990907: BeppoSAX follow up and X-ray afterglow
  53. GRB990907 and 990908
  54. GRB 990712 Late Optical Decay and Host Galaxy
  55. GRB990806 BeppoSAX follow up
  56. GRB990806: BATSE Observations
  57. GRB 990806 Optical observations
  58. GRB 990806, Optical Observations
  59. GRB 990806, optical observations
  60. GRB 990806, Optical Observations
  61. GRB990806 UBVRIJHK observations
  62. GRB 990712 Optical Observations
  63. GRB 990712
  64. Late-time HST/STIS Observations of GRB 990510
  65. BeppoSAX NFI Observation of GRB990705
  66. BeppoSAX NFI Observation of GRB990705
  67. GRB 990705, R-band observations
  68. Infrared and Optical Observations of GRB990705
  69. GRB990704: SAX-NFI results summary
  70. GRB990704 radio and optical observations
  71. GRB990704
  72. GRB990704, optical observations
  73. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  74. Optical Observations of GRB990627
  75. BeppoSAX: GRB990625
  76. Late-time HST/STIS Observation of GRB 990123
  77. Optical Observations of GRB 990506
  78. GRB990527 Optical Observations
  79. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  80. Late Afterglows of GRBs 990510, 990123
  81. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  82. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  83. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  84. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  85. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  86. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  87. radio observations of X-ray/GRB transient field
  88. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  89. Optical report on X-ray/GRB transient
  90. radio detection of X-ray/GRB transient
  91. BeppoSAX: A new fast X-ray transient
  92. GRB 990510: optical observations
  93. GRB 990510: optical linear polarization
  94. GRB 990510: optical observations
  95. GRB990510: X-ray afterglow
  96. GRB 990510: Broad Band Break
  97. GRB 990510: BATSE Observations
  98. GRB 990510: BeppoSAX/GRBM observations
  99. GRB990510 optical observations
  100. GRB 990510 optical observations

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