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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"

22059 results found.

  1. IPN error boxes for GRB991229
  2. GRB 991216: J band spectrophotometry
  3. IPN localization of GRB991226
  4. Single IPN error box for GRB991221
  5. IPN error boxes for GRB991221
  6. GRB 991216 RXTE ASM Observations
  7. IPN error box for GRB991216
  8. Lowell/Perkins observation of GRB 991216
  9. GRB 991217 (SAX J2303.2+0015) Optical observations
  10. GRB991217/SAX J2303.2+0015, optical observations
  11. GRB 991216, optical observations
  12. GRB 991216 Optical Observations
  13. GRB991216 Optical and IR observations
  14. K observations of GRB991216
  15. SAX J2303.2+0015 Optical observations
  16. IR observations of GRB991216
  17. GRB991216 radio observations
  18. GRB 991217 (SAX J2303.2+0015) Optical observations
  19. GRB991216 radio observations
  20. GRB991216, optical observations
  21. GRB991216 Optical and infrared observations of Beethoven Burst
  22. GRB 991216 Radio Observations
  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 991216, Optical Transient
  30. GRB 991216, Optical Afterglow
  31. GRB991216 ('Beethoven Burst') B, R, and K Observations
  32. GRB991216, infrared observations
  33. GRB991216 Optical Observations
  34. GRB 991208 optical observations
  35. GRB 991208 Keck Spectroscopy
  36. GRB 991216: Extremely bright BATSE burst
  37. R-band Observations of GRB991208 at TNG
  38. GRB991208, optical observations
  39. GRB 991208 Keck Spectroscopy
  40. GRB991208 15-GHz observations
  41. GRB991208, optical observations
  42. GRB 991208 - OVRO detection
  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. GRB 991106, radio observations
  52. GRB 991105: BATSE Observations
  53. IPN localization of GRB991105
  54. GRB 991106 Optical Observations
  55. GRB 991105, optical observations
  56. GRB 991106, LOTIS Optical Observations
  57. GRB 991106, optical observations
  58. GRB 991014, Optical Observations
  59. GRB 991014 - BeppoSAX NFI observations
  60. GRB 991014, Optical Observations
  61. GRB 991014, radio observations
  62. GRB991014 BATSE Observations
  63. GRB 991014, Optical Observations
  64. GRB 991014, optical observations
  65. GRB 990915 optical observations
  66. GRB 990907 optical observations
  67. Optical Observations of GRB990907
  68. IPN error box for GRB990915 (=BATSE 7766)
  69. GRB990907 and 990908
  70. GRB 990712 Late Optical Decay and Host Galaxy
  71. GRB 990712, Optical Observation
  72. GRB990806: BATSE Observations
  73. GRB 990806 Optical observations
  74. Optical Observations of GRB990806
  75. GRB 990806, Optical Observations
  76. GRB 990806, optical observations
  77. GRB 990806, Optical Observations
  78. GRB990806 UBVRIJHK observations
  79. GRB 990712 Optical Observations
  80. GRB 990712
  81. Late-time HST/STIS Observations of GRB 990510
  82. GRB 990705, R-band observations
  83. Updated IPN localization of GRB990705
  84. Infrared and Optical Observations of GRB990705
  85. GRB 990705, radio observations
  86. GRB990704 radio and optical observations
  87. BeppoSAX GRB990705: possible X-ray afterglow
  88. GRB 990704 X-ray Observations
  89. GRB 990704 Optical Observations
  90. GRB 990704, optical observations
  91. GRB990705: Intriguing Positional Coincidences
  92. GRB990704
  93. GRB990704, optical observations
  94. Identification of a possible optical counterpart for GRB990704
  95. GRB990704
  96. Optical Observations of GRB990627
  97. GRB 990627, radio observations
  98. Late-time HST/STIS Observation of GRB 990123
  99. GRB 990506 - Optical Observations
  100. Optical Observations of GRB 990506

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