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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"

42174 results found.

  1. Lowell/Perkins observation of GRB 991216
  2. GRB 991217 (SAX J2303.2+0015) Optical observations
  3. GRB991217/SAX J2303.2+0015, optical observations
  4. Chandra observation of the X-ray afterglow of GRB991216
  5. GRB 991216, optical observations
  6. GRB 991216 Optical Observations
  7. GRB 991216 Optical spectroscopy/imaging
  8. VLT spectra of GRB991216
  9. GRB991216 Optical and IR observations
  10. K observations of GRB991216
  11. SAX J2303.2+0015 Optical observations
  12. IR observations of GRB991216
  13. GRB991216 radio observations
  14. GRB 991217 (SAX J2303.2+0015) Optical observations
  15. GRB991216 radio observations
  16. GRB991216 Spectroscopy
  17. Lowell/Perkins observation of GRB 991216
  18. GRB991216, optical observations
  19. GRB991216 Optical and infrared observations of Beethoven Burst
  20. Refined IPN localization of GRB991216
  21. GRB 991216 Radio Observations
  22. GRB 991217
  23. GRB 991208 Keck Spectroscopy
  24. GRB 991208 Infrared Detection
  25. GRB991216
  26. GRB 991216--Summary of RXTE Observations
  27. GRB 991216 Optical Observations
  28. GRB 991216, optical observations
  29. GRB 991208 SAO-RAS Spectroscopy
  30. SAX J2303.2+0015: an x-ray/GRB?
  31. GRB 991216, Optical Transient
  32. GRB 991216, Optical Afterglow
  33. GRB991216 ('Beethoven Burst') B, R, and K Observations
  34. GRB 991216: Comparison with DPOSS images
  35. GRB991216, infrared observations
  36. GRB991216 Optical Observations
  37. GRB 991208 optical observations
  38. Lowell/Perkins observation of GRB 991216
  39. GRB 991216 Optical Observation
  40. GRB 991208 Keck Spectroscopy
  41. GRB 991216: Extremely bright BATSE burst
  42. R-band Observations of GRB991208 at TNG
  43. GRB991208, optical observations
  44. GRB 991208 Keck Spectroscopy
  45. GRB991208 - millimeter detection
  46. GRB 991208, Optical Observation
  47. GRB991208 15-GHz observations
  48. GRB991208, optical observations
  49. GRB 991208 - OVRO detection
  50. GRB 991208 Optical Decay
  51. GRB 991208 optical observations
  52. GRB 991208 optical observations
  53. GRB 991208: Radio Observations
  54. IPN localization of GRB991208
  55. Optical Observations of GRB991105
  56. GRB991106: BeppoSAX/BATSE results
  57. GRB 991106, optical observations
  58. GRB991106, near-infrared observations
  59. BeppoSAX NFI Observation of GRB991106
  60. GRB 991106, radio observations
  61. GRB991106: the first BeppoSAX short GRB detection?
  62. GRB 991105: BATSE Observations
  63. GRB 991106 Optical Observations
  64. GRB 991105, optical observations
  65. GRB991106, optical observation at SAO-RAS
  66. GRB 991106, LOTIS Optical Observations
  67. GRB 991106, optical observations
  68. BeppoSAX refined position for GRB991106
  69. BeppoSAX GRB Alert: GRB991106
  70. Revised BeppoSAX WFC position of GRB991105
  71. GRB991105: SAX-GRBM/-WFC detection
  72. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  73. GRB ALERT: GRB991105
  74. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  75. GRB 991014, Optical Observations
  76. GRB 991014 - BeppoSAX NFI observations
  77. GRB 991014, Optical Observations
  78. GRB 991014, radio observations
  79. GRB991014 BATSE Observations
  80. GRB 991014, Optical Observations
  81. GRB 991014, optical observations
  82. Super-LOTIS optical observation of 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. Optical Observations of GRB990907
  89. GRB990907: BeppoSAX follow up and X-ray afterglow
  90. GRB990907 and 990908
  91. IPN localization of GRB990907
  92. GRB990907: refined WFC position
  93. GRB 990712 Late Optical Decay and Host Galaxy
  94. GRB 990712, Optical Observation
  95. GRB990806 BeppoSAX follow up
  96. GRB990806: BATSE Observations
  97. GRB 990806 Optical observations
  98. Optical Observations of GRB990806
  99. GRB 990806, Optical Observations
  100. GRB 990806, optical observations

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