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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"

41682 results found.

  1. BATSE location of GRB000126
  2. IPN localization of GRB000126
  3. GRB 000115 Optical observations
  4. BATSE Observations of GRB000115
  5. Correction to GCN 520 (IPN annulus for GRB000115)
  6. IPN annulus for GRB000115
  7. Second RXTE Observation of GRB 000115
  8. GRB991216, UBVRIJHK field photometry
  9. GRB991216 late optical observation
  10. Single IPN error box for GRB991229
  11. GCN resumes full operations
  12. GRB 991216 VLBA Observations
  13. BEPPOSAX GRBM Localization of GRB991226
  14. GRB 991216: J band spectrophotometry
  15. GRB 991216: Detection of the Host and/or Absorber Galaxy
  16. Single IPN error box for GRB991221
  17. GRB 991216 RXTE ASM Observations
  18. IPN error box for GRB991216
  19. GRB 991216: Updated BATSE parameters
  20. Lowell/Perkins observation of GRB 991216
  21. GRB 991217 (SAX J2303.2+0015) Optical observations
  22. GRB991217/SAX J2303.2+0015, optical observations
  23. Chandra observation of the X-ray afterglow of GRB991216
  24. GRB 991216, optical observations
  25. GRB 991216 Optical Observations
  26. GRB 991216 Optical spectroscopy/imaging
  27. VLT spectra of GRB991216
  28. GRB991216 Optical and IR observations
  29. K observations of GRB991216
  30. SAX J2303.2+0015 Optical observations
  31. IR observations of GRB991216
  32. GRB991216 radio observations
  33. GRB 991217 (SAX J2303.2+0015) Optical observations
  34. GRB991216 radio observations
  35. Lowell/Perkins observation of GRB 991216
  36. GRB991216, optical observations
  37. GRB991216 Optical and infrared observations of Beethoven Burst
  38. Refined IPN localization of GRB991216
  39. GRB 991216 Radio Observations
  40. GRB 991217
  41. GRB 991208 Keck Spectroscopy
  42. GRB 991208 Infrared Detection
  43. GRB991216
  44. GRB 991216--Summary of RXTE Observations
  45. GRB 991216 Optical Observations
  46. GRB 991216, optical observations
  47. GRB 991208 SAO-RAS Spectroscopy
  48. SAX J2303.2+0015: an x-ray/GRB?
  49. GRB 991216, Optical Transient
  50. GRB 991216, Optical Afterglow
  51. GRB991216 ('Beethoven Burst') B, R, and K Observations
  52. GRB 991216: Comparison with DPOSS images
  53. GRB991216, infrared observations
  54. GRB991216 Optical Observations
  55. GRB 991208 optical observations
  56. Lowell/Perkins observation of GRB 991216
  57. GRB 991216 Optical Observation
  58. GRB 991208 Keck Spectroscopy
  59. GRB 991216: Extremely bright BATSE burst
  60. R-band Observations of GRB991208 at TNG
  61. GRB991208, optical observations
  62. GRB 991208 Keck Spectroscopy
  63. GRB991208 - millimeter detection
  64. GRB 991208, Optical Observation
  65. GRB991208 15-GHz observations
  66. GRB991208, optical observations
  67. GRB 991208 - OVRO detection
  68. GRB 991208 Optical Decay
  69. GRB 991208 optical observations
  70. GRB 991208 optical observations
  71. GRB 991208: Radio Observations
  72. Optical Observations of GRB991105
  73. GRB991106: BeppoSAX/BATSE results
  74. GRB 991106, optical observations
  75. GRB991106, near-infrared observations
  76. BeppoSAX NFI Observation of GRB991106
  77. GRB 991106, radio observations
  78. GRB991106: the first BeppoSAX short GRB detection?
  79. GRB 991105: BATSE Observations
  80. IPN localization of GRB991105
  81. GRB 991106 Optical Observations
  82. GRB 991105, optical observations
  83. GRB991106, optical observation at SAO-RAS
  84. GRB 991106, LOTIS Optical Observations
  85. GRB 991106, optical observations
  86. Revised BeppoSAX WFC position of GRB991105
  87. GRB991105: SAX-GRBM/-WFC detection
  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. GRB991014 BATSE Observations
  93. GRB 991014, Optical Observations
  94. GRB 991014, optical observations
  95. Super-LOTIS optical observation of GRB991014
  96. IPN/NFI error box for GRB991014
  97. IPN localization of GRB991014 - CORRECTION
  98. IPN localization of GRB991014
  99. GRB 990915 optical observations
  100. GRB 990907 optical observations

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