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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"

24595 results found.

  1. Optical observations of GRB000210
  2. GRB000210 X-ray afterglow
  3. GRB000214: X-ray afterglow candidate
  4. GRB000214 refined BeppoSAX-WFC position
  5. GRB 000210: BATSE Observations
  6. Optical observations of the Chandra X-ray source for GRB000210
  7. GRB000210, Radio Observations
  8. IPN triangulation of GRB000210
  9. GRB000210: possible afterglow detection with BeppoSAX NFI
  10. GRB000201, Radio Observations
  11. GRB000210: BeppoSAX GRBM and WFC Detection
  12. SAX_WFC_GRB_NOTICE
  13. SAX_WFC_GRB_NOTICE
  14. GRB000201 Optical Observations
  15. GRB 000201: TAROT optical observations
  16. GRB 991208, radio observations
  17. BATSE+IPN location of GRB000131
  18. IPN localization of GRB000131
  19. GRB 000126, optical observations
  20. BATSE Observations of GRB000115
  21. Second RXTE Observation of GRB 000115
  22. GRB991216, UBVRIJHK field photometry
  23. GCN resumes full operations
  24. GRB 991216 VLBA Observations
  25. GRB 991216: J band spectrophotometry
  26. GRB 991216: Detection of the Host and/or Absorber Galaxy
  27. IPN localization of GRB991226
  28. GRB 991216 RXTE ASM Observations
  29. GRB 991216: Updated BATSE parameters
  30. GRB 991217 (SAX J2303.2+0015) Optical observations
  31. Chandra observation of the X-ray afterglow of GRB991216
  32. GRB 991216, optical observations
  33. GRB 991216 Optical spectroscopy/imaging
  34. SAX J2303.2+0015 Optical observations
  35. IR observations of GRB991216
  36. GRB 991217 (SAX J2303.2+0015) Optical observations
  37. GRB991216 Optical and infrared observations of Beethoven Burst
  38. GRB 991216 Radio Observations
  39. GRB 991208 Keck Spectroscopy
  40. GRB 991208 Infrared Detection
  41. GRB991216
  42. GRB 991216--Summary of RXTE Observations
  43. GRB 991216 Optical Observations
  44. GRB 991216, optical observations
  45. GRB 991208 SAO-RAS Spectroscopy
  46. SAX J2303.2+0015: an x-ray/GRB?
  47. GRB 991216, Optical Transient
  48. GRB991216 ('Beethoven Burst') B, R, and K Observations
  49. GRB991216, infrared observations
  50. GRB 991208 optical observations
  51. GRB 991216 Optical Observation
  52. GRB 991216: Extremely bright BATSE burst
  53. R-band Observations of GRB991208 at TNG
  54. GRB991208, optical observations
  55. GRB 991208, Optical Observation
  56. GRB991208, optical observations
  57. GRB 991208 optical observations
  58. Optical Observations of GRB991105
  59. GRB991106: BeppoSAX/BATSE results
  60. GRB991106, near-infrared observations
  61. BeppoSAX NFI Observation of GRB991106
  62. GRB 991106, radio observations
  63. GRB991106: the first BeppoSAX short GRB detection?
  64. GRB 991105: BATSE Observations
  65. GRB 991106 Optical Observations
  66. GRB991106, optical observation at SAO-RAS
  67. GRB 991106, LOTIS Optical Observations
  68. GRB991105: SAX-GRBM/-WFC detection
  69. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  70. GRB 991014, Optical Observations
  71. GRB 991014 - BeppoSAX NFI observations
  72. GRB 991014, radio observations
  73. GRB 991014, Optical Observations
  74. GRB 991014, optical observations
  75. GRB 990915 optical observations
  76. Optical Observations of GRB990907
  77. GRB990907: BeppoSAX follow up and X-ray afterglow
  78. GRB990907 and 990908
  79. GRB 990712 Late Optical Decay and Host Galaxy
  80. GRB990806 BeppoSAX follow up
  81. GRB990806: BATSE Observations
  82. GRB 990806 Optical observations
  83. GRB 990806, Optical Observations
  84. GRB 990806, optical observations
  85. GRB 990806, Optical Observations
  86. GRB990806 UBVRIJHK observations
  87. GRB 990712 Optical Observations
  88. GRB 990712
  89. Late-time HST/STIS Observations of GRB 990510
  90. BeppoSAX NFI Observation of GRB990705
  91. BeppoSAX NFI Observation of GRB990705
  92. GRB 990705, R-band observations
  93. Infrared and Optical Observations of GRB990705
  94. GRB990704: SAX-NFI results summary
  95. GRB990704 radio and optical observations
  96. GRB990704
  97. GRB990704, optical observations
  98. BeppoSAX NFI Observation of GRB990627 X-ray afterglow
  99. Optical Observations of GRB990627
  100. BeppoSAX: GRB990625

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