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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"

32507 results found.

  1. GRB 000115 Optical observations
  2. GRB 000214, Radio Observations
  3. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  4. GRB000210, Radio Observations
  5. Correction to GCN 557 (GRB000214: BeppoSAX GRBM and WFC Detection)
  6. IPN annulus for GRB000214
  7. Optical observations of GRB000210
  8. GRB000210 X-ray afterglow
  9. GRB 000210: BATSE Observations
  10. Correction to Chandra Position of GRB000210 afterglow
  11. Optical observations of the Chandra X-ray source for GRB000210
  12. GRB000210, Radio Observations
  13. Optical candidate for GRB000210
  14. Chandra Observations of GRB000210 X-ray Afterglow
  15. IPN triangulation of GRB000210
  16. GRB000201, Radio Observations
  17. Optical observations of GRB000131
  18. GRB000201 Optical Observations
  19. GRB 000131 Optical Observations
  20. GRB000126 Optical Observations
  21. GRB 991208, radio observations
  22. BATSE+IPN location of GRB000131
  23. GRB 000126, optical observations
  24. GRB000126, optical observations
  25. BATSE location of GRB000126
  26. GRB 000115 Optical observations
  27. BATSE Observations of GRB000115
  28. Correction to GCN 520 (IPN annulus for GRB000115)
  29. IPN annulus for GRB000115
  30. GRB991216, UBVRIJHK field photometry
  31. GRB991216 late optical observation
  32. Single IPN error box for GRB991229
  33. GCN resumes full operations
  34. GRB 991216 VLBA Observations
  35. BEPPOSAX GRBM Localization of GRB991226
  36. GRB 991216: J band spectrophotometry
  37. GRB 991216: Detection of the Host and/or Absorber Galaxy
  38. Single IPN error box for GRB991221
  39. GRB 991216 RXTE ASM Observations
  40. IPN error box for GRB991216
  41. Lowell/Perkins observation of GRB 991216
  42. GRB 991217 (SAX J2303.2+0015) Optical observations
  43. GRB991217/SAX J2303.2+0015, optical observations
  44. Chandra observation of the X-ray afterglow of GRB991216
  45. GRB 991216, optical observations
  46. GRB 991216 Optical Observations
  47. GRB 991216 Optical spectroscopy/imaging
  48. VLT spectra of GRB991216
  49. GRB991216 Optical and IR observations
  50. SAX J2303.2+0015 Optical observations
  51. IR observations of GRB991216
  52. GRB991216 radio observations
  53. GRB 991217 (SAX J2303.2+0015) Optical observations
  54. GRB991216 radio observations
  55. Lowell/Perkins observation of GRB 991216
  56. GRB991216, optical observations
  57. Refined IPN localization of GRB991216
  58. GRB 991216 Radio Observations
  59. GRB 991208 Keck Spectroscopy
  60. GRB 991208 Infrared Detection
  61. GRB991216
  62. GRB 991216--Summary of RXTE Observations
  63. GRB 991216 Optical Observations
  64. GRB 991216, optical observations
  65. GRB 991208 SAO-RAS Spectroscopy
  66. GRB 991216, Optical Transient
  67. GRB 991216, Optical Afterglow
  68. GRB991216 ('Beethoven Burst') B, R, and K Observations
  69. GRB 991216: Comparison with DPOSS images
  70. GRB 991208 optical observations
  71. Lowell/Perkins observation of GRB 991216
  72. GRB 991216 Optical Observation
  73. GRB 991208 Keck Spectroscopy
  74. R-band Observations of GRB991208 at TNG
  75. GRB991208, optical observations
  76. GRB 991208 Keck Spectroscopy
  77. GRB991208 - millimeter detection
  78. GRB 991208, Optical Observation
  79. GRB991208 15-GHz observations
  80. GRB991208, optical observations
  81. GRB 991208 - OVRO detection
  82. GRB 991208 Optical Decay
  83. GRB 991208 optical observations
  84. GRB 991208 optical observations
  85. GRB 991208: Radio Observations
  86. Optical Observations of GRB991105
  87. GRB991106: BeppoSAX/BATSE results
  88. GRB 991106, optical observations
  89. GRB991106, near-infrared observations
  90. BeppoSAX NFI Observation of GRB991106
  91. GRB 991106, radio observations
  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. Revised BeppoSAX WFC position of GRB991105
  100. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI

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