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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"

45637 results found.

  1. GRB 000131 Optical Observations
  2. GRB000126 Optical Observations
  3. BATSE GRB trigger criteria changed
  4. GRB 991208, radio observations
  5. BATSE+IPN location of GRB000131
  6. IPN localization of GRB000131
  7. GRB 000126, optical observations
  8. GRB000126, optical observations
  9. BATSE location of GRB000126
  10. IPN localization of GRB000126
  11. GRB 000115 Optical observations
  12. BATSE Observations of GRB000115
  13. Correction to GCN 520 (IPN annulus for GRB000115)
  14. IPN annulus for GRB000115
  15. Second RXTE Observation of GRB 000115
  16. GRB991216, UBVRIJHK field photometry
  17. GRB991216 late optical observation
  18. Single IPN error box for GRB991229
  19. GCN resumes full operations
  20. GRB 991216 VLBA Observations
  21. BEPPOSAX GRBM Localization of GRB991226
  22. IPN error boxes for GRB991229
  23. GRB 991216: J band spectrophotometry
  24. GRB 991216: Detection of the Host and/or Absorber Galaxy
  25. IPN localization of GRB991226
  26. Single IPN error box for GRB991221
  27. IPN error boxes for GRB991221
  28. GRB 991216 RXTE ASM Observations
  29. IPN error box for GRB991216
  30. GRB 991216: Updated BATSE parameters
  31. Lowell/Perkins observation of GRB 991216
  32. GRB 991217 (SAX J2303.2+0015) Optical observations
  33. GRB991217/SAX J2303.2+0015, optical observations
  34. Chandra observation of the X-ray afterglow of GRB991216
  35. GRB 991216, optical observations
  36. GRB 991216 Optical Observations
  37. GRB 991216 Optical spectroscopy/imaging
  38. VLT spectra of GRB991216
  39. GRB991216 Optical and IR observations
  40. K observations of GRB991216
  41. SAX J2303.2+0015 Optical observations
  42. IR observations of GRB991216
  43. GRB991216 radio observations
  44. GRB 991217 (SAX J2303.2+0015) Optical observations
  45. GRB991216 radio observations
  46. GRB991216 Spectroscopy
  47. Lowell/Perkins observation of GRB 991216
  48. GRB991216, optical observations
  49. GRB991216 Optical and infrared observations of Beethoven Burst
  50. Refined IPN localization of GRB991216
  51. GRB 991216 Radio Observations
  52. GRB 991217
  53. GRB 991208 Keck Spectroscopy
  54. GRB 991208 Infrared Detection
  55. GRB991216
  56. GRB 991216--Summary of RXTE Observations
  57. GRB 991216 Optical Observations
  58. GRB 991216, optical observations
  59. GRB 991208 SAO-RAS Spectroscopy
  60. SAX J2303.2+0015: an x-ray/GRB?
  61. GRB 991216, Optical Transient
  62. GRB 991216, Optical Afterglow
  63. GRB991216 ('Beethoven Burst') B, R, and K Observations
  64. GRB 991216: Comparison with DPOSS images
  65. GRB991216, infrared observations
  66. GRB991216 Optical Observations
  67. GRB 991208 optical observations
  68. Lowell/Perkins observation of GRB 991216
  69. GRB 991216 Optical Observation
  70. GRB 991208 Keck Spectroscopy
  71. GRB 991216: Extremely bright BATSE burst
  72. R-band Observations of GRB991208 at TNG
  73. GRB991208, optical observations
  74. GRB 991208 Keck Spectroscopy
  75. GRB991208 - millimeter detection
  76. GRB 991208, Optical Observation
  77. GRB991208 15-GHz observations
  78. GRB991208, optical observations
  79. GRB 991208 - OVRO detection
  80. GRB 991208 Optical Decay
  81. GRB 991208 optical observations
  82. GRB 991208 optical observations
  83. GRB 991208: Radio Observations
  84. IPN localization of GRB991208
  85. Optical Observations of GRB991105
  86. GRB991106: BeppoSAX/BATSE results
  87. GRB 991106, optical observations
  88. GRB991106, near-infrared observations
  89. BeppoSAX NFI Observation of GRB991106
  90. GRB 991106, radio observations
  91. GRB991106: the first BeppoSAX short GRB detection?
  92. GRB 991105: BATSE Observations
  93. IPN localization of GRB991105
  94. GRB 991106 Optical Observations
  95. GRB 991105, optical observations
  96. GRB991106, optical observation at SAO-RAS
  97. GRB 991106, LOTIS Optical Observations
  98. GRB 991106, optical observations
  99. BeppoSAX refined position for GRB991106
  100. BeppoSAX GRB Alert: GRB991106

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Download all Circulars as a .tar.gz archive (updated once a day):
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