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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"

32495 results found.

  1. Optical candidate for GRB000210
  2. Chandra Observations of GRB000210 X-ray Afterglow
  3. IPN triangulation of GRB000210
  4. GRB000201, Radio Observations
  5. Optical observations of GRB000131
  6. GRB000201 Optical Observations
  7. GRB 000131 Optical Observations
  8. GRB000126 Optical Observations
  9. GRB 991208, radio observations
  10. BATSE+IPN location of GRB000131
  11. GRB 000126, optical observations
  12. GRB000126, optical observations
  13. BATSE location of GRB000126
  14. GRB 000115 Optical observations
  15. BATSE Observations of GRB000115
  16. Correction to GCN 520 (IPN annulus for GRB000115)
  17. IPN annulus for GRB000115
  18. GRB991216, UBVRIJHK field photometry
  19. GRB991216 late optical observation
  20. Single IPN error box for GRB991229
  21. GCN resumes full operations
  22. GRB 991216 VLBA Observations
  23. BEPPOSAX GRBM Localization of GRB991226
  24. GRB 991216: J band spectrophotometry
  25. GRB 991216: Detection of the Host and/or Absorber Galaxy
  26. Single IPN error box for GRB991221
  27. GRB 991216 RXTE ASM Observations
  28. IPN error box for GRB991216
  29. Lowell/Perkins observation of GRB 991216
  30. GRB 991217 (SAX J2303.2+0015) Optical observations
  31. GRB991217/SAX J2303.2+0015, optical observations
  32. Chandra observation of the X-ray afterglow of GRB991216
  33. GRB 991216, optical observations
  34. GRB 991216 Optical Observations
  35. GRB 991216 Optical spectroscopy/imaging
  36. VLT spectra of GRB991216
  37. GRB991216 Optical and IR observations
  38. SAX J2303.2+0015 Optical observations
  39. IR observations of GRB991216
  40. GRB991216 radio observations
  41. GRB 991217 (SAX J2303.2+0015) Optical observations
  42. GRB991216 radio observations
  43. Lowell/Perkins observation of GRB 991216
  44. GRB991216, optical observations
  45. Refined IPN localization of GRB991216
  46. GRB 991216 Radio Observations
  47. GRB 991208 Keck Spectroscopy
  48. GRB 991208 Infrared Detection
  49. GRB991216
  50. GRB 991216--Summary of RXTE Observations
  51. GRB 991216 Optical Observations
  52. GRB 991216, optical observations
  53. GRB 991208 SAO-RAS Spectroscopy
  54. GRB 991216, Optical Transient
  55. GRB 991216, Optical Afterglow
  56. GRB991216 ('Beethoven Burst') B, R, and K Observations
  57. GRB 991216: Comparison with DPOSS images
  58. GRB 991208 optical observations
  59. Lowell/Perkins observation of GRB 991216
  60. GRB 991216 Optical Observation
  61. GRB 991208 Keck Spectroscopy
  62. R-band Observations of GRB991208 at TNG
  63. GRB991208, optical observations
  64. GRB 991208 Keck Spectroscopy
  65. GRB991208 - millimeter detection
  66. GRB 991208, Optical Observation
  67. GRB991208 15-GHz observations
  68. GRB991208, optical observations
  69. GRB 991208 - OVRO detection
  70. GRB 991208 Optical Decay
  71. GRB 991208 optical observations
  72. GRB 991208 optical observations
  73. GRB 991208: Radio Observations
  74. Optical Observations of GRB991105
  75. GRB991106: BeppoSAX/BATSE results
  76. GRB 991106, optical observations
  77. GRB991106, near-infrared observations
  78. BeppoSAX NFI Observation of GRB991106
  79. GRB 991106, radio observations
  80. GRB 991105: BATSE Observations
  81. IPN localization of GRB991105
  82. GRB 991106 Optical Observations
  83. GRB 991105, optical observations
  84. GRB991106, optical observation at SAO-RAS
  85. GRB 991106, LOTIS Optical Observations
  86. GRB 991106, optical observations
  87. Revised BeppoSAX WFC position of 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, Optical Observations
  93. GRB 991014, optical observations
  94. Super-LOTIS optical observation of GRB991014
  95. IPN/NFI error box for GRB991014
  96. IPN localization of GRB991014 - CORRECTION
  97. IPN localization of GRB991014
  98. GRB 990915 optical observations
  99. GRB 990907 optical observations
  100. Optical Observations of GRB990907

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