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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"

25777 results found.

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

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