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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"

20558 results found.

  1. GRB 991216: Detection of the Host and/or Absorber Galaxy
  2. GRB 991216 RXTE ASM Observations
  3. Lowell/Perkins observation of GRB 991216
  4. GRB 991217 (SAX J2303.2+0015) Optical observations
  5. GRB991217/SAX J2303.2+0015, optical observations
  6. GRB 991216, optical observations
  7. GRB 991216 Optical Observations
  8. GRB 991216 Optical spectroscopy/imaging
  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, optical observations
  17. GRB991216 Optical and infrared observations of Beethoven Burst
  18. GRB 991216 Radio Observations
  19. GRB 991208 Keck Spectroscopy
  20. GRB 991208 Infrared Detection
  21. GRB 991216--Summary of RXTE Observations
  22. GRB 991216 Optical Observations
  23. GRB 991216, optical observations
  24. GRB 991208 SAO-RAS Spectroscopy
  25. GRB 991216, Optical Transient
  26. GRB 991216, Optical Afterglow
  27. GRB991216 ('Beethoven Burst') B, R, and K Observations
  28. GRB991216, infrared observations
  29. GRB991216 Optical Observations
  30. GRB 991208 optical observations
  31. GRB 991208 Keck Spectroscopy
  32. GRB 991216: Extremely bright BATSE burst
  33. R-band Observations of GRB991208 at TNG
  34. GRB991208, optical observations
  35. GRB 991208 Keck Spectroscopy
  36. GRB991208 15-GHz observations
  37. GRB991208, optical observations
  38. GRB 991208 - OVRO detection
  39. GRB 991208 optical observations
  40. GRB 991208 optical observations
  41. GRB 991208: Radio Observations
  42. Optical Observations of GRB991105
  43. GRB991106: BeppoSAX/BATSE results
  44. GRB 991106, optical observations
  45. GRB991106, near-infrared observations
  46. GRB 991106, radio observations
  47. GRB 991105: BATSE Observations
  48. GRB 991106 Optical Observations
  49. GRB 991105, optical observations
  50. GRB 991106, LOTIS Optical Observations
  51. GRB 991106, optical observations
  52. GRB 991014, Optical Observations
  53. GRB 991014 - BeppoSAX NFI observations
  54. GRB 991014, Optical Observations
  55. GRB 991014, radio observations
  56. GRB991014 BATSE Observations
  57. GRB 991014, Optical Observations
  58. GRB 991014, optical observations
  59. GRB 990915 optical observations
  60. GRB 990907 optical observations
  61. Optical Observations of GRB990907
  62. GRB990907 and 990908
  63. GRB 990712 Late Optical Decay and Host Galaxy
  64. GRB 990712, Optical Observation
  65. GRB990806: BATSE Observations
  66. GRB 990806 Optical observations
  67. Optical Observations of GRB990806
  68. GRB 990806, Optical Observations
  69. GRB 990806, optical observations
  70. GRB 990806, Optical Observations
  71. GRB990806 UBVRIJHK observations
  72. GRB 990712 Optical Observations
  73. GRB 990712 Optical Decay: Indication of Bright Host Galaxy
  74. GRB 990712
  75. Late-time HST/STIS Observations of GRB 990510
  76. GRB 990705, R-band observations
  77. Infrared and Optical Observations of GRB990705
  78. GRB 990705, radio observations
  79. GRB990704 radio and optical observations
  80. GRB 990704 X-ray Observations
  81. GRB 990704 Optical Observations
  82. GRB 990704, optical observations
  83. GRB990705: Intriguing Positional Coincidences
  84. GRB990704
  85. GRB990704, optical observations
  86. Identification of a possible optical counterpart for GRB990704
  87. GRB990704
  88. Optical Observations of GRB990627
  89. GRB 990627, radio observations
  90. Late-time HST/STIS Observation of GRB 990123
  91. GRB 990506 - clarification to GCN 352
  92. GRB 990506 - Optical Observations
  93. Optical Observations of GRB 990506
  94. GRB990527 Optical Observations
  95. Late Afterglows of GRBs 990510, 990123
  96. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  97. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  98. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  99. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  100. X-ray/GRB 1SAX J0835.9+5118, Optical Observation

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