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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"

44394 results found.

  1. VLT spectra of GRB991216
  2. GRB991216 Optical and IR observations
  3. K observations of GRB991216
  4. SAX J2303.2+0015 Optical observations
  5. IR observations of GRB991216
  6. GRB991216 radio observations
  7. GRB991216 radio observations
  8. GRB991216 Spectroscopy
  9. Lowell/Perkins observation of GRB 991216
  10. GRB991216, optical observations
  11. GRB991216 Optical and infrared observations of Beethoven Burst
  12. Refined IPN localization of GRB991216
  13. GRB 991216 Radio Observations
  14. GRB 991217
  15. GRB 991208 Keck Spectroscopy
  16. GRB 991208 Infrared Detection
  17. GRB991216
  18. GRB 991216--Summary of RXTE Observations
  19. GRB 991216 Optical Observations
  20. GRB 991216, optical observations
  21. GRB 991208 SAO-RAS Spectroscopy
  22. SAX J2303.2+0015: an x-ray/GRB?
  23. GRB 991216, Optical Transient
  24. GRB 991216, Optical Afterglow
  25. GRB991216 ('Beethoven Burst') B, R, and K Observations
  26. GRB 991216: Comparison with DPOSS images
  27. GRB991216, infrared observations
  28. GRB991216 Optical Observations
  29. GRB 991208 optical observations
  30. Lowell/Perkins observation of GRB 991216
  31. GRB 991216 Optical Observation
  32. GRB 991208 Keck Spectroscopy
  33. GRB 991216: Extremely bright BATSE burst
  34. R-band Observations of GRB991208 at TNG
  35. GRB991208, optical observations
  36. GRB 991208 Keck Spectroscopy
  37. GRB991208 - millimeter detection
  38. GRB 991208, Optical Observation
  39. GRB991208 15-GHz observations
  40. GRB991208, optical observations
  41. GRB 991208 - OVRO detection
  42. GRB 991208 Optical Decay
  43. GRB 991208 optical observations
  44. GRB 991208 optical observations
  45. GRB 991208: Radio Observations
  46. IPN localization of GRB991208
  47. Optical Observations of GRB991105
  48. GRB991106: BeppoSAX/BATSE results
  49. GRB 991106, optical observations
  50. GRB991106, near-infrared observations
  51. BeppoSAX NFI Observation of GRB991106
  52. GRB 991106, radio observations
  53. GRB991106: the first BeppoSAX short GRB detection?
  54. GRB 991105: BATSE Observations
  55. IPN localization of GRB991105
  56. GRB 991106 Optical Observations
  57. GRB 991105, optical observations
  58. GRB991106, optical observation at SAO-RAS
  59. GRB 991106, LOTIS Optical Observations
  60. GRB 991106, optical observations
  61. BeppoSAX refined position for GRB991106
  62. BeppoSAX GRB Alert: GRB991106
  63. Revised BeppoSAX WFC position of GRB991105
  64. GRB991105: SAX-GRBM/-WFC detection
  65. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  66. GRB ALERT: GRB991105
  67. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  68. GRB 991014, Optical Observations
  69. GRB 991014 - BeppoSAX NFI observations
  70. GRB 991014, Optical Observations
  71. GRB 991014, radio observations
  72. GRB991014 BATSE Observations
  73. GRB 991014, Optical Observations
  74. GRB 991014, optical observations
  75. Super-LOTIS optical observation of GRB991014
  76. IPN/NFI error box for GRB991014
  77. IPN localization of GRB991014 - CORRECTION
  78. IPN localization of GRB991014
  79. BeppoSAX ALERT: GRB991014
  80. GRB 990915 optical observations
  81. GRB 990907 optical observations
  82. Optical Observations of GRB990907
  83. IPN error box for GRB990915 (=BATSE 7766)
  84. IPN localization of BATSE #7766 (GRB990915)
  85. GRB990907: BeppoSAX follow up and X-ray afterglow
  86. GRB990907 and 990908
  87. IPN localization of GRB990907
  88. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  89. GRB990907: refined WFC position
  90. BeppoSAX MAIL n. 99/24: GRB ALERT: GRB990907
  91. GRB 990712 Late Optical Decay and Host Galaxy
  92. GRB 990712, Optical Observation
  93. GRB990806 BeppoSAX follow up
  94. GRB990806: BATSE Observations
  95. GRB 990806 Optical observations
  96. Optical Observations of GRB990806
  97. GRB 990806, Optical Observations
  98. GRB 990806, optical observations
  99. GRB 990806, Optical Observations
  100. GRB990806 UBVRIJHK observations

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