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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"

24600 results found.

  1. GRB 000214 near-IR observations
  2. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  3. GRB000210, Radio Observations
  4. GRB 000115, BVRI field photometry
  5. GRB000214: BeppoSAX GRBM and WFC Detection
  6. Optical observations of GRB000210
  7. GRB000210 X-ray afterglow
  8. GRB000214: X-ray afterglow candidate
  9. GRB000214 refined BeppoSAX-WFC position
  10. GRB 000210: BATSE Observations
  11. Optical observations of the Chandra X-ray source for GRB000210
  12. GRB000210, Radio Observations
  13. IPN triangulation of GRB000210
  14. GRB000210: possible afterglow detection with BeppoSAX NFI
  15. GRB000201, Radio Observations
  16. GRB000210: BeppoSAX GRBM and WFC Detection
  17. SAX_WFC_GRB_NOTICE
  18. SAX_WFC_GRB_NOTICE
  19. GRB000201 Optical Observations
  20. GRB 000201: TAROT optical observations
  21. GRB 991208, radio observations
  22. BATSE+IPN location of GRB000131
  23. IPN localization of GRB000131
  24. GRB 000126, optical observations
  25. BATSE Observations of GRB000115
  26. Second RXTE Observation of GRB 000115
  27. GRB991216, UBVRIJHK field photometry
  28. GCN resumes full operations
  29. GRB 991216 VLBA Observations
  30. GRB 991216: J band spectrophotometry
  31. GRB 991216: Detection of the Host and/or Absorber Galaxy
  32. IPN localization of GRB991226
  33. GRB 991216 RXTE ASM Observations
  34. GRB 991216: Updated BATSE parameters
  35. GRB 991217 (SAX J2303.2+0015) Optical observations
  36. Chandra observation of the X-ray afterglow of GRB991216
  37. GRB 991216, optical observations
  38. GRB 991216 Optical spectroscopy/imaging
  39. SAX J2303.2+0015 Optical observations
  40. IR observations of GRB991216
  41. GRB 991217 (SAX J2303.2+0015) Optical observations
  42. GRB991216 Optical and infrared observations of Beethoven Burst
  43. GRB 991216 Radio Observations
  44. GRB 991208 Keck Spectroscopy
  45. GRB 991208 Infrared Detection
  46. GRB991216
  47. GRB 991216--Summary of RXTE Observations
  48. GRB 991216 Optical Observations
  49. GRB 991216, optical observations
  50. GRB 991208 SAO-RAS Spectroscopy
  51. SAX J2303.2+0015: an x-ray/GRB?
  52. GRB 991216, Optical Transient
  53. GRB991216 ('Beethoven Burst') B, R, and K Observations
  54. GRB991216, infrared observations
  55. GRB 991208 optical observations
  56. GRB 991216 Optical Observation
  57. GRB 991216: Extremely bright BATSE burst
  58. R-band Observations of GRB991208 at TNG
  59. GRB991208, optical observations
  60. GRB 991208, Optical Observation
  61. GRB991208, optical observations
  62. GRB 991208 optical observations
  63. Optical Observations of GRB991105
  64. GRB991106: BeppoSAX/BATSE results
  65. GRB991106, near-infrared observations
  66. BeppoSAX NFI Observation of GRB991106
  67. GRB 991106, radio observations
  68. GRB991106: the first BeppoSAX short GRB detection?
  69. GRB 991105: BATSE Observations
  70. GRB 991106 Optical Observations
  71. GRB991106, optical observation at SAO-RAS
  72. GRB 991106, LOTIS Optical Observations
  73. GRB991105: SAX-GRBM/-WFC detection
  74. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  75. GRB 991014, Optical Observations
  76. GRB 991014 - BeppoSAX NFI observations
  77. GRB 991014, radio observations
  78. GRB 991014, Optical Observations
  79. GRB 991014, optical observations
  80. GRB 990915 optical observations
  81. Optical Observations of GRB990907
  82. GRB990907: BeppoSAX follow up and X-ray afterglow
  83. GRB990907 and 990908
  84. GRB 990712 Late Optical Decay and Host Galaxy
  85. GRB990806 BeppoSAX follow up
  86. GRB990806: BATSE Observations
  87. GRB 990806 Optical observations
  88. GRB 990806, Optical Observations
  89. GRB 990806, optical observations
  90. GRB 990806, Optical Observations
  91. GRB990806 UBVRIJHK observations
  92. GRB 990712 Optical Observations
  93. GRB 990712
  94. Late-time HST/STIS Observations of GRB 990510
  95. BeppoSAX NFI Observation of GRB990705
  96. BeppoSAX NFI Observation of GRB990705
  97. GRB 990705, R-band observations
  98. Infrared and Optical Observations of GRB990705
  99. GRB990704: SAX-NFI results summary
  100. GRB990704 radio and optical observations

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