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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"

18324 results found.

  1. GRB 000301C: HST/STIS CCD Imaging of the field
  2. GRB 000301C Optical Observations
  3. GRB 000301C: K' Observations
  4. GRB000301C - Host galaxy not detected in R (?)
  5. Optical observations of GRB000301c
  6. GRB000301C, Radio observations
  7. GRB000301C, Radio observations
  8. GRB 000301c near-IR observations
  9. GRB 000301C, UBVRI field photometry
  10. GRB 000301C: OT confirmed
  11. GRB000301c optical observations
  12. GRB000301C
  13. GRB 000301C : Optical Candidate
  14. HST Observations of GRB 990712
  15. GRB 000214 near-IR observations
  16. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  17. GRB000210, Radio Observations
  18. GRB 000115, BVRI field photometry
  19. GRB000214: BeppoSAX GRBM and WFC Detection
  20. Optical observations of GRB000210
  21. GRB000210 X-ray afterglow
  22. GRB000214: X-ray afterglow candidate
  23. GRB000214 refined BeppoSAX-WFC position
  24. Optical observations of the Chandra X-ray source for GRB000210
  25. GRB000210, Radio Observations
  26. GRB000201, Radio Observations
  27. GRB000210: BeppoSAX GRBM and WFC Detection
  28. GRB000201 Optical Observations
  29. GRB 000126, optical observations
  30. GRB991216, UBVRIJHK field photometry
  31. GCN resumes full operations
  32. GRB 991216: Detection of the Host and/or Absorber Galaxy
  33. IPN error box for GRB991216
  34. GRB 991217 (SAX J2303.2+0015) Optical observations
  35. Chandra observation of the X-ray afterglow of GRB991216
  36. SAX J2303.2+0015 Optical observations
  37. IR observations of GRB991216
  38. GRB 991217 (SAX J2303.2+0015) Optical observations
  39. GRB 991216 Radio Observations
  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. GRB991208, optical observations
  54. GRB 991208, Optical Observation
  55. GRB991208, optical observations
  56. Optical Observations of GRB991105
  57. GRB991106: BeppoSAX/BATSE results
  58. BeppoSAX NFI Observation of GRB991106
  59. GRB 991106, radio observations
  60. GRB991106: the first BeppoSAX short GRB detection?
  61. GRB 991106 Optical Observations
  62. GRB991106, optical observation at SAO-RAS
  63. GRB 991106, LOTIS Optical Observations
  64. GRB991105: SAX-GRBM/-WFC detection
  65. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  66. GRB 991014, Optical Observations
  67. GRB 991014 - BeppoSAX NFI observations
  68. GRB 991014, radio observations
  69. GRB 991014, Optical Observations
  70. GRB 991014, optical observations
  71. Super-LOTIS optical observation of GRB991014
  72. Optical Observations of GRB990907
  73. GRB990907 and 990908
  74. GRB990806 BeppoSAX follow up
  75. GRB 990806 Optical observations
  76. GRB 990806, optical observations
  77. GRB 990806, Optical Observations
  78. GRB 990712 Optical Observations
  79. GRB 990712
  80. Late-time HST/STIS Observations of GRB 990510
  81. BeppoSAX NFI Observation of GRB990705
  82. BeppoSAX NFI Observation of GRB990705
  83. GRB 990705, R-band observations
  84. GRB990704: SAX-NFI results summary
  85. GRB990704 radio and optical observations
  86. GRB990704
  87. GRB990704, optical observations
  88. Late-time HST/STIS Observation of GRB 990123
  89. Optical Observations of GRB 990506
  90. GRB990527 Optical Observations
  91. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  92. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  93. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  94. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  95. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  96. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  97. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  98. radio observations of X-ray/GRB transient field
  99. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  100. Optical report on X-ray/GRB transient

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