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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"

32503 results found.

  1. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  2. IPN annulus for GRB000214
  3. Optical observations of GRB000210
  4. GRB000210 X-ray afterglow
  5. GRB 000210: BATSE Observations
  6. Correction to Chandra Position of GRB000210 afterglow
  7. Optical observations of the Chandra X-ray source for GRB000210
  8. GRB000210, Radio Observations
  9. Optical candidate for GRB000210
  10. Chandra Observations of GRB000210 X-ray Afterglow
  11. IPN triangulation of GRB000210
  12. GRB000201, Radio Observations
  13. Optical observations of GRB000131
  14. GRB000201 Optical Observations
  15. GRB 000131 Optical Observations
  16. GRB000126 Optical Observations
  17. GRB 991208, radio observations
  18. BATSE+IPN location of GRB000131
  19. GRB 000126, optical observations
  20. GRB000126, optical observations
  21. BATSE location of GRB000126
  22. GRB 000115 Optical observations
  23. BATSE Observations of GRB000115
  24. Correction to GCN 520 (IPN annulus for GRB000115)
  25. IPN annulus for GRB000115
  26. GRB991216, UBVRIJHK field photometry
  27. GRB991216 late optical observation
  28. Single IPN error box for GRB991229
  29. GCN resumes full operations
  30. GRB 991216 VLBA Observations
  31. BEPPOSAX GRBM Localization of GRB991226
  32. GRB 991216: J band spectrophotometry
  33. GRB 991216: Detection of the Host and/or Absorber Galaxy
  34. Single IPN error box for GRB991221
  35. GRB 991216 RXTE ASM Observations
  36. IPN error box for GRB991216
  37. Lowell/Perkins observation of GRB 991216
  38. GRB 991217 (SAX J2303.2+0015) Optical observations
  39. GRB991217/SAX J2303.2+0015, optical observations
  40. Chandra observation of the X-ray afterglow of GRB991216
  41. GRB 991216, optical observations
  42. GRB 991216 Optical Observations
  43. GRB 991216 Optical spectroscopy/imaging
  44. VLT spectra of GRB991216
  45. GRB991216 Optical and IR observations
  46. SAX J2303.2+0015 Optical observations
  47. IR observations of GRB991216
  48. GRB991216 radio observations
  49. GRB 991217 (SAX J2303.2+0015) Optical observations
  50. GRB991216 radio observations
  51. Lowell/Perkins observation of GRB 991216
  52. GRB991216, optical observations
  53. Refined IPN localization of GRB991216
  54. GRB 991216 Radio Observations
  55. GRB 991208 Keck Spectroscopy
  56. GRB 991208 Infrared Detection
  57. GRB991216
  58. GRB 991216--Summary of RXTE Observations
  59. GRB 991216 Optical Observations
  60. GRB 991216, optical observations
  61. GRB 991208 SAO-RAS Spectroscopy
  62. GRB 991216, Optical Transient
  63. GRB 991216, Optical Afterglow
  64. GRB991216 ('Beethoven Burst') B, R, and K Observations
  65. GRB 991216: Comparison with DPOSS images
  66. GRB 991208 optical observations
  67. Lowell/Perkins observation of GRB 991216
  68. GRB 991216 Optical Observation
  69. GRB 991208 Keck Spectroscopy
  70. R-band Observations of GRB991208 at TNG
  71. GRB991208, optical observations
  72. GRB 991208 Keck Spectroscopy
  73. GRB991208 - millimeter detection
  74. GRB 991208, Optical Observation
  75. GRB991208 15-GHz observations
  76. GRB991208, optical observations
  77. GRB 991208 - OVRO detection
  78. GRB 991208 Optical Decay
  79. GRB 991208 optical observations
  80. GRB 991208 optical observations
  81. GRB 991208: Radio Observations
  82. Optical Observations of GRB991105
  83. GRB991106: BeppoSAX/BATSE results
  84. GRB 991106, optical observations
  85. GRB991106, near-infrared observations
  86. BeppoSAX NFI Observation of GRB991106
  87. GRB 991106, radio observations
  88. GRB 991105: BATSE Observations
  89. IPN localization of GRB991105
  90. GRB 991106 Optical Observations
  91. GRB 991105, optical observations
  92. GRB991106, optical observation at SAO-RAS
  93. GRB 991106, LOTIS Optical Observations
  94. GRB 991106, optical observations
  95. Revised BeppoSAX WFC position of GRB991105
  96. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  97. GRB 991014, Optical Observations
  98. GRB 991014 - BeppoSAX NFI observations
  99. GRB 991014, Optical Observations
  100. GRB 991014, Optical Observations

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