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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"

24978 results found.

  1. IPN localization of GRB000131
  2. GRB 000126, optical observations
  3. BATSE Observations of GRB000115
  4. Second RXTE Observation of GRB 000115
  5. GRB991216, UBVRIJHK field photometry
  6. GCN resumes full operations
  7. GRB 991216 VLBA Observations
  8. GRB 991216: J band spectrophotometry
  9. GRB 991216: Detection of the Host and/or Absorber Galaxy
  10. IPN localization of GRB991226
  11. GRB 991216 RXTE ASM Observations
  12. GRB 991216: Updated BATSE parameters
  13. GRB 991217 (SAX J2303.2+0015) Optical observations
  14. Chandra observation of the X-ray afterglow of GRB991216
  15. GRB 991216, optical observations
  16. GRB 991216 Optical spectroscopy/imaging
  17. SAX J2303.2+0015 Optical observations
  18. IR observations of GRB991216
  19. GRB 991217 (SAX J2303.2+0015) Optical observations
  20. GRB991216 Optical and infrared observations of Beethoven Burst
  21. GRB 991216 Radio Observations
  22. GRB 991208 Keck Spectroscopy
  23. GRB 991208 Infrared Detection
  24. GRB991216
  25. GRB 991216--Summary of RXTE Observations
  26. GRB 991216 Optical Observations
  27. GRB 991216, optical observations
  28. GRB 991208 SAO-RAS Spectroscopy
  29. SAX J2303.2+0015: an x-ray/GRB?
  30. GRB 991216, Optical Transient
  31. GRB991216 ('Beethoven Burst') B, R, and K Observations
  32. GRB991216, infrared observations
  33. GRB 991208 optical observations
  34. GRB 991216 Optical Observation
  35. GRB 991216: Extremely bright BATSE burst
  36. R-band Observations of GRB991208 at TNG
  37. GRB991208, optical observations
  38. GRB 991208, Optical Observation
  39. GRB991208, optical observations
  40. GRB 991208 optical observations
  41. Optical Observations of GRB991105
  42. GRB991106: BeppoSAX/BATSE results
  43. GRB991106, near-infrared observations
  44. BeppoSAX NFI Observation of GRB991106
  45. GRB 991106, radio observations
  46. GRB991106: the first BeppoSAX short GRB detection?
  47. GRB 991105: BATSE Observations
  48. GRB 991106 Optical Observations
  49. GRB991106, optical observation at SAO-RAS
  50. GRB 991106, LOTIS Optical Observations
  51. GRB991105: SAX-GRBM/-WFC detection
  52. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  53. GRB 991014, Optical Observations
  54. GRB 991014 - BeppoSAX NFI observations
  55. GRB 991014, radio observations
  56. GRB 991014, Optical Observations
  57. GRB 991014, optical observations
  58. GRB 990915 optical observations
  59. Optical Observations of GRB990907
  60. GRB990907: BeppoSAX follow up and X-ray afterglow
  61. GRB990907 and 990908
  62. GRB 990712 Late Optical Decay and Host Galaxy
  63. GRB990806 BeppoSAX follow up
  64. GRB990806: BATSE Observations
  65. GRB 990806 Optical observations
  66. GRB 990806, Optical Observations
  67. GRB 990806, optical observations
  68. GRB 990806, Optical Observations
  69. GRB990806 UBVRIJHK observations
  70. GRB 990712 Optical Observations
  71. GRB 990712
  72. Late-time HST/STIS Observations of GRB 990510
  73. BeppoSAX NFI Observation of GRB990705
  74. BeppoSAX NFI Observation of GRB990705
  75. GRB 990705, R-band observations
  76. Infrared and Optical Observations of GRB990705
  77. GRB990704: SAX-NFI results summary
  78. GRB990704 radio and optical observations
  79. GRB990704
  80. GRB990704, optical observations
  81. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  82. Optical Observations of GRB990627
  83. BeppoSAX: GRB990625
  84. Late-time HST/STIS Observation of GRB 990123
  85. Optical Observations of GRB 990506
  86. GRB990527 Optical Observations
  87. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  88. Late Afterglows of GRBs 990510, 990123
  89. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  90. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  91. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  92. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  93. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  94. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  95. radio observations of X-ray/GRB transient field
  96. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  97. Optical report on X-ray/GRB transient
  98. radio detection of X-ray/GRB transient
  99. BeppoSAX: A new fast X-ray transient
  100. GRB 990510: optical observations

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