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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"

28082 results found.

  1. GRB000201 Optical Observations
  2. GRB 000201: TAROT optical observations
  3. GRB 991208, radio observations
  4. BATSE+IPN location of GRB000131
  5. IPN localization of GRB000131
  6. GRB 000126, optical observations
  7. BATSE Observations of GRB000115
  8. Second RXTE Observation of GRB 000115
  9. GRB991216, UBVRIJHK field photometry
  10. GCN resumes full operations
  11. GRB 991216 VLBA Observations
  12. GRB 991216: J band spectrophotometry
  13. GRB 991216: Detection of the Host and/or Absorber Galaxy
  14. IPN localization of GRB991226
  15. GRB 991216 RXTE ASM Observations
  16. GRB 991216: Updated BATSE parameters
  17. GRB 991217 (SAX J2303.2+0015) Optical observations
  18. Chandra observation of the X-ray afterglow of GRB991216
  19. GRB 991216, optical observations
  20. GRB 991216 Optical spectroscopy/imaging
  21. SAX J2303.2+0015 Optical observations
  22. IR observations of GRB991216
  23. GRB 991217 (SAX J2303.2+0015) Optical observations
  24. GRB991216 Optical and infrared observations of Beethoven Burst
  25. GRB 991216 Radio Observations
  26. GRB 991208 Keck Spectroscopy
  27. GRB 991208 Infrared Detection
  28. GRB991216
  29. GRB 991216--Summary of RXTE Observations
  30. GRB 991216 Optical Observations
  31. GRB 991216, optical observations
  32. GRB 991208 SAO-RAS Spectroscopy
  33. SAX J2303.2+0015: an x-ray/GRB?
  34. GRB 991216, Optical Transient
  35. GRB991216 ('Beethoven Burst') B, R, and K Observations
  36. GRB991216, infrared observations
  37. GRB 991208 optical observations
  38. GRB 991216 Optical Observation
  39. GRB 991216: Extremely bright BATSE burst
  40. R-band Observations of GRB991208 at TNG
  41. GRB991208, optical observations
  42. GRB 991208, Optical Observation
  43. GRB991208, optical observations
  44. GRB 991208 optical observations
  45. Optical Observations of GRB991105
  46. GRB991106: BeppoSAX/BATSE results
  47. GRB991106, near-infrared observations
  48. BeppoSAX NFI Observation of GRB991106
  49. GRB 991106, radio observations
  50. GRB991106: the first BeppoSAX short GRB detection?
  51. GRB 991105: BATSE Observations
  52. GRB 991106 Optical Observations
  53. GRB991106, optical observation at SAO-RAS
  54. GRB 991106, LOTIS Optical Observations
  55. GRB991105: SAX-GRBM/-WFC detection
  56. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  57. GRB 991014, Optical Observations
  58. GRB 991014 - BeppoSAX NFI observations
  59. GRB 991014, radio observations
  60. GRB 991014, Optical Observations
  61. GRB 991014, optical observations
  62. GRB 990915 optical observations
  63. Optical Observations of GRB990907
  64. GRB990907: BeppoSAX follow up and X-ray afterglow
  65. GRB990907 and 990908
  66. GRB 990712 Late Optical Decay and Host Galaxy
  67. GRB990806 BeppoSAX follow up
  68. GRB990806: BATSE Observations
  69. GRB 990806 Optical observations
  70. GRB 990806, Optical Observations
  71. GRB 990806, optical observations
  72. GRB 990806, Optical Observations
  73. GRB990806 UBVRIJHK observations
  74. GRB 990712 Optical Observations
  75. GRB 990712
  76. Late-time HST/STIS Observations of GRB 990510
  77. BeppoSAX NFI Observation of GRB990705
  78. BeppoSAX NFI Observation of GRB990705
  79. GRB 990705, R-band observations
  80. Infrared and Optical Observations of GRB990705
  81. GRB990704: SAX-NFI results summary
  82. GRB990704 radio and optical observations
  83. GRB990704
  84. GRB990704, optical observations
  85. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  86. Optical Observations of GRB990627
  87. BeppoSAX: GRB990625
  88. Late-time HST/STIS Observation of GRB 990123
  89. Optical Observations of GRB 990506
  90. GRB990527 Optical Observations
  91. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  92. Late Afterglows of GRBs 990510, 990123
  93. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  94. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  95. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  96. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  97. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  98. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  99. radio observations of X-ray/GRB transient field
  100. optical observation of the X-ray/GRB transient SAX J0835.9+5118

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