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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"

44505 results found.

  1. GRB991217/SAX J2303.2+0015, optical observations
  2. Chandra observation of the X-ray afterglow of GRB991216
  3. GRB 991216, optical observations
  4. GRB 991216 Optical Observations
  5. GRB 991216 Optical spectroscopy/imaging
  6. VLT spectra of GRB991216
  7. GRB991216 Optical and IR observations
  8. K observations of GRB991216
  9. SAX J2303.2+0015 Optical observations
  10. IR observations of GRB991216
  11. GRB991216 radio observations
  12. GRB 991217 (SAX J2303.2+0015) Optical observations
  13. GRB991216 radio observations
  14. GRB991216 Spectroscopy
  15. Lowell/Perkins observation of GRB 991216
  16. GRB991216, optical observations
  17. GRB991216 Optical and infrared observations of Beethoven Burst
  18. Refined IPN localization of GRB991216
  19. GRB 991216 Radio Observations
  20. GRB 991217
  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. GRB 991216, Optical Afterglow
  31. GRB991216 ('Beethoven Burst') B, R, and K Observations
  32. GRB 991216: Comparison with DPOSS images
  33. GRB991216, infrared observations
  34. GRB991216 Optical Observations
  35. GRB 991208 optical observations
  36. Lowell/Perkins observation of GRB 991216
  37. GRB 991216 Optical Observation
  38. GRB 991208 Keck Spectroscopy
  39. GRB 991216: Extremely bright BATSE burst
  40. R-band Observations of GRB991208 at TNG
  41. GRB991208, optical observations
  42. GRB 991208 Keck Spectroscopy
  43. GRB991208 - millimeter detection
  44. GRB 991208, Optical Observation
  45. GRB991208 15-GHz observations
  46. GRB991208, optical observations
  47. GRB 991208 - OVRO detection
  48. GRB 991208 Optical Decay
  49. GRB 991208 optical observations
  50. GRB 991208 optical observations
  51. GRB 991208: Radio Observations
  52. IPN localization of GRB991208
  53. Optical Observations of GRB991105
  54. GRB991106: BeppoSAX/BATSE results
  55. GRB 991106, optical observations
  56. GRB991106, near-infrared observations
  57. BeppoSAX NFI Observation of GRB991106
  58. GRB 991106, radio observations
  59. GRB991106: the first BeppoSAX short GRB detection?
  60. GRB 991105: BATSE Observations
  61. IPN localization of GRB991105
  62. GRB 991106 Optical Observations
  63. GRB 991105, optical observations
  64. GRB991106, optical observation at SAO-RAS
  65. GRB 991106, LOTIS Optical Observations
  66. GRB 991106, optical observations
  67. BeppoSAX refined position for GRB991106
  68. BeppoSAX GRB Alert: GRB991106
  69. Revised BeppoSAX WFC position of GRB991105
  70. GRB991105: SAX-GRBM/-WFC detection
  71. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  72. GRB ALERT: GRB991105
  73. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  74. GRB 991014, Optical Observations
  75. GRB 991014 - BeppoSAX NFI observations
  76. GRB 991014, Optical Observations
  77. GRB 991014, radio observations
  78. GRB991014 BATSE Observations
  79. GRB 991014, Optical Observations
  80. GRB 991014, optical observations
  81. Super-LOTIS optical observation of GRB991014
  82. IPN/NFI error box for GRB991014
  83. IPN localization of GRB991014 - CORRECTION
  84. IPN localization of GRB991014
  85. BeppoSAX ALERT: GRB991014
  86. GRB 990915 optical observations
  87. GRB 990907 optical observations
  88. BATSE GRB trigger criteria
  89. Optical Observations of GRB990907
  90. IPN error box for GRB990915 (=BATSE 7766)
  91. IPN localization of BATSE #7766 (GRB990915)
  92. GRB990907: BeppoSAX follow up and X-ray afterglow
  93. GRB990907 and 990908
  94. IPN localization of GRB990907
  95. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  96. GRB990907: refined WFC position
  97. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  98. GRB 990712 Late Optical Decay and Host Galaxy
  99. GRB 990712, Optical Observation
  100. GRB990806 BeppoSAX follow up

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