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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"

41188 results found.

  1. BATSE location of GRB000126
  2. GRB 000115 Optical observations
  3. BATSE Observations of GRB000115
  4. IPN annulus for GRB000115
  5. Second RXTE Observation of GRB 000115
  6. GRB991216, UBVRIJHK field photometry
  7. GRB991216 late optical observation
  8. GCN resumes full operations
  9. GRB 991216 VLBA Observations
  10. IPN error boxes for GRB991229
  11. GRB 991216: J band spectrophotometry
  12. GRB 991216: Detection of the Host and/or Absorber Galaxy
  13. GRB 991216 RXTE ASM Observations
  14. IPN error box for GRB991216
  15. Lowell/Perkins observation of GRB 991216
  16. GRB 991217 (SAX J2303.2+0015) Optical observations
  17. GRB991217/SAX J2303.2+0015, optical observations
  18. Chandra observation of the X-ray afterglow of GRB991216
  19. GRB 991216, optical observations
  20. GRB 991216 Optical Observations
  21. GRB 991216 Optical spectroscopy/imaging
  22. VLT spectra of GRB991216
  23. GRB991216 Optical and IR observations
  24. K observations of GRB991216
  25. SAX J2303.2+0015 Optical observations
  26. IR observations of GRB991216
  27. GRB991216 radio observations
  28. GRB 991217 (SAX J2303.2+0015) Optical observations
  29. GRB991216 radio observations
  30. GRB991216 Spectroscopy
  31. Lowell/Perkins observation of GRB 991216
  32. GRB991216, optical observations
  33. GRB991216 Optical and infrared observations of Beethoven Burst
  34. Refined IPN localization of GRB991216
  35. GRB 991216 Radio Observations
  36. GRB 991217
  37. GRB 991208 Keck Spectroscopy
  38. GRB 991208 Infrared Detection
  39. GRB991216
  40. GRB 991216--Summary of RXTE Observations
  41. GRB 991216 Optical Observations
  42. GRB 991216, optical observations
  43. GRB 991208 SAO-RAS Spectroscopy
  44. SAX J2303.2+0015: an x-ray/GRB?
  45. GRB 991216, Optical Transient
  46. GRB 991216, Optical Afterglow
  47. GRB991216 ('Beethoven Burst') B, R, and K Observations
  48. GRB 991216: Comparison with DPOSS images
  49. GRB991216, infrared observations
  50. GRB991216 Optical Observations
  51. GRB 991208 optical observations
  52. Lowell/Perkins observation of GRB 991216
  53. GRB 991216 Optical Observation
  54. GRB 991208 Keck Spectroscopy
  55. GRB 991216: Extremely bright BATSE burst
  56. R-band Observations of GRB991208 at TNG
  57. GRB991208, optical observations
  58. GRB 991208 Keck Spectroscopy
  59. GRB991208 - millimeter detection
  60. GRB 991208, Optical Observation
  61. GRB991208 15-GHz observations
  62. GRB991208, optical observations
  63. GRB 991208 - OVRO detection
  64. GRB 991208 Optical Decay
  65. GRB 991208 optical observations
  66. GRB 991208 optical observations
  67. GRB 991208: Radio Observations
  68. IPN localization of GRB991208
  69. Optical Observations of GRB991105
  70. GRB991106: BeppoSAX/BATSE results
  71. GRB 991106, optical observations
  72. GRB991106, near-infrared observations
  73. BeppoSAX NFI Observation of GRB991106
  74. GRB 991106, radio observations
  75. GRB991106: the first BeppoSAX short GRB detection?
  76. GRB 991105: BATSE Observations
  77. GRB 991106 Optical Observations
  78. GRB 991105, optical observations
  79. GRB991106, optical observation at SAO-RAS
  80. GRB 991106, LOTIS Optical Observations
  81. GRB 991106, optical observations
  82. BeppoSAX refined position for GRB991106
  83. BeppoSAX GRB Alert: GRB991106
  84. Revised BeppoSAX WFC position of GRB991105
  85. GRB991105: SAX-GRBM/-WFC detection
  86. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  87. GRB ALERT: GRB991105
  88. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  89. GRB 991014, Optical Observations
  90. GRB 991014 - BeppoSAX NFI observations
  91. GRB 991014, Optical Observations
  92. GRB 991014, radio observations
  93. GRB991014 BATSE Observations
  94. GRB 991014, Optical Observations
  95. GRB 991014, optical observations
  96. Super-LOTIS optical observation of GRB991014
  97. IPN localization of GRB991014 - CORRECTION
  98. IPN localization of GRB991014
  99. BeppoSAX ALERT: GRB991014
  100. GRB 990915 optical observations

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