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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"

28090 results found.

  1. Optical observations of the Chandra X-ray source for GRB000210
  2. GRB000210, Radio Observations
  3. IPN triangulation of GRB000210
  4. GRB000210: possible afterglow detection with BeppoSAX NFI
  5. GRB000201, Radio Observations
  6. GRB000210: BeppoSAX GRBM and WFC Detection
  7. SAX_WFC_GRB_NOTICE
  8. SAX_WFC_GRB_NOTICE
  9. GRB000201 Optical Observations
  10. GRB 000201: TAROT optical observations
  11. GRB 991208, radio observations
  12. BATSE+IPN location of GRB000131
  13. IPN localization of GRB000131
  14. GRB 000126, optical observations
  15. BATSE Observations of GRB000115
  16. Second RXTE Observation of GRB 000115
  17. GRB991216, UBVRIJHK field photometry
  18. GCN resumes full operations
  19. GRB 991216 VLBA Observations
  20. GRB 991216: J band spectrophotometry
  21. GRB 991216: Detection of the Host and/or Absorber Galaxy
  22. IPN localization of GRB991226
  23. GRB 991216 RXTE ASM Observations
  24. GRB 991216: Updated BATSE parameters
  25. GRB 991217 (SAX J2303.2+0015) Optical observations
  26. Chandra observation of the X-ray afterglow of GRB991216
  27. GRB 991216, optical observations
  28. GRB 991216 Optical spectroscopy/imaging
  29. SAX J2303.2+0015 Optical observations
  30. IR observations of GRB991216
  31. GRB 991217 (SAX J2303.2+0015) Optical observations
  32. GRB991216 Optical and infrared observations of Beethoven Burst
  33. GRB 991216 Radio Observations
  34. GRB 991208 Keck Spectroscopy
  35. GRB 991208 Infrared Detection
  36. GRB991216
  37. GRB 991216--Summary of RXTE Observations
  38. GRB 991216 Optical Observations
  39. GRB 991216, optical observations
  40. GRB 991208 SAO-RAS Spectroscopy
  41. SAX J2303.2+0015: an x-ray/GRB?
  42. GRB 991216, Optical Transient
  43. GRB991216 ('Beethoven Burst') B, R, and K Observations
  44. GRB991216, infrared observations
  45. GRB 991208 optical observations
  46. GRB 991216 Optical Observation
  47. GRB 991216: Extremely bright BATSE burst
  48. R-band Observations of GRB991208 at TNG
  49. GRB991208, optical observations
  50. GRB 991208, Optical Observation
  51. GRB991208, optical observations
  52. GRB 991208 optical observations
  53. Optical Observations of GRB991105
  54. GRB991106: BeppoSAX/BATSE results
  55. GRB991106, near-infrared observations
  56. BeppoSAX NFI Observation of GRB991106
  57. GRB 991106, radio observations
  58. GRB991106: the first BeppoSAX short GRB detection?
  59. GRB 991105: BATSE Observations
  60. GRB 991106 Optical Observations
  61. GRB991106, optical observation at SAO-RAS
  62. GRB 991106, LOTIS Optical Observations
  63. GRB991105: SAX-GRBM/-WFC detection
  64. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  65. GRB 991014, Optical Observations
  66. GRB 991014 - BeppoSAX NFI observations
  67. GRB 991014, radio observations
  68. GRB 991014, Optical Observations
  69. GRB 991014, optical observations
  70. GRB 990915 optical observations
  71. Optical Observations of GRB990907
  72. GRB990907: BeppoSAX follow up and X-ray afterglow
  73. GRB990907 and 990908
  74. GRB 990712 Late Optical Decay and Host Galaxy
  75. GRB990806 BeppoSAX follow up
  76. GRB990806: BATSE Observations
  77. GRB 990806 Optical observations
  78. GRB 990806, Optical Observations
  79. GRB 990806, optical observations
  80. GRB 990806, Optical Observations
  81. GRB990806 UBVRIJHK observations
  82. GRB 990712 Optical Observations
  83. GRB 990712
  84. Late-time HST/STIS Observations of GRB 990510
  85. BeppoSAX NFI Observation of GRB990705
  86. BeppoSAX NFI Observation of GRB990705
  87. GRB 990705, R-band observations
  88. Infrared and Optical Observations of GRB990705
  89. GRB990704: SAX-NFI results summary
  90. GRB990704 radio and optical observations
  91. GRB990704
  92. GRB990704, optical observations
  93. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  94. Optical Observations of GRB990627
  95. BeppoSAX: GRB990625
  96. Late-time HST/STIS Observation of GRB 990123
  97. Optical Observations of GRB 990506
  98. GRB990527 Optical Observations
  99. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  100. Late Afterglows of GRBs 990510, 990123

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