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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"

43604 results found.

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

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