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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"

15714 results found.

  1. GRB 000131 Optical Observations
  2. GRB000126 Optical Observations
  3. GRB 000126, optical observations
  4. GRB000126, optical observations
  5. GRB 000115 Optical observations
  6. GRB991216 late optical observation
  7. GRB 991216 VLBA Observations
  8. GRB 991216: J band spectrophotometry
  9. GRB 991216 RXTE ASM Observations
  10. IPN error box for GRB991216
  11. GRB 991217 (SAX J2303.2+0015) Optical observations
  12. GRB991217/SAX J2303.2+0015, optical observations
  13. Chandra observation of the X-ray afterglow of GRB991216
  14. GRB 991216, optical observations
  15. GRB 991216 Optical Observations
  16. GRB 991216 Optical spectroscopy/imaging
  17. VLT spectra of GRB991216
  18. GRB991216 Optical and IR observations
  19. SAX J2303.2+0015 Optical observations
  20. IR observations of GRB991216
  21. GRB991216 radio observations
  22. GRB 991217 (SAX J2303.2+0015) Optical observations
  23. GRB991216 radio observations
  24. GRB991216, optical observations
  25. GRB991216 Optical and infrared observations of Beethoven Burst
  26. Refined IPN localization of GRB991216
  27. GRB 991216 Radio Observations
  28. GRB 991208 Infrared Detection
  29. GRB 991216--Summary of RXTE Observations
  30. GRB 991216 Optical Observations
  31. GRB 991216, optical observations
  32. GRB 991208 SAO-RAS Spectroscopy
  33. GRB 991216, Optical Transient
  34. GRB 991216, Optical Afterglow
  35. GRB991216 ('Beethoven Burst') B, R, and K 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. R-band Observations of GRB991208 at TNG
  42. GRB991208, optical observations
  43. GRB 991208, Optical Observation
  44. GRB991208, optical observations
  45. GRB 991208 Optical Decay
  46. GRB 991208 optical observations
  47. GRB 991208 optical observations
  48. GRB 991208: Radio Observations
  49. Optical Observations of GRB991105
  50. GRB 991106, optical observations
  51. GRB 991106 Optical Observations
  52. GRB 991105, optical observations
  53. GRB991106, optical observation at SAO-RAS
  54. GRB 991106, LOTIS Optical Observations
  55. GRB 991106, optical observations
  56. GRB 991014, Optical Observations
  57. GRB 991014, Optical Observations
  58. GRB 991014, Optical Observations
  59. GRB 991014, optical observations
  60. Super-LOTIS optical observation of GRB991014
  61. GRB 990915 optical observations
  62. GRB 990907 optical observations
  63. Optical Observations of GRB990907
  64. GRB 990712 Late Optical Decay and Host Galaxy
  65. GRB 990712, Optical Observation
  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. VLT spectrum of GRB990712
  75. GRB 990712
  76. GRB 990705, R-band observations
  77. IPN localization of GRB990704
  78. Infrared and Optical Observations of GRB990705
  79. GRB990704 radio and optical observations
  80. GRB 990704 Optical Observations
  81. GRB 990704, optical observations
  82. GRB990704
  83. GRB990704
  84. GRB990704, optical observations
  85. Identification of a possible optical counterpart for GRB990704
  86. GRB990704
  87. Optical Observations of GRB990627
  88. Late-time HST/STIS Observation of GRB 990123
  89. GRB 990506 - Optical Observations
  90. Optical Observations of GRB 990506
  91. GRB 990506 Radio Transient
  92. GRB990527 Optical Observations
  93. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  94. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  95. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  96. GRB 990506 optical observation
  97. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  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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