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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"

32490 results found.

  1. GRB000201 Optical Observations
  2. GRB 000131 Optical Observations
  3. GRB000126 Optical Observations
  4. GRB 991208, radio observations
  5. BATSE+IPN location of GRB000131
  6. GRB 000126, optical observations
  7. GRB000126, optical observations
  8. BATSE location of GRB000126
  9. GRB 000115 Optical observations
  10. BATSE Observations of GRB000115
  11. Correction to GCN 520 (IPN annulus for GRB000115)
  12. IPN annulus for GRB000115
  13. GRB991216, UBVRIJHK field photometry
  14. GRB991216 late optical observation
  15. Single IPN error box for GRB991229
  16. GCN resumes full operations
  17. GRB 991216 VLBA Observations
  18. BEPPOSAX GRBM Localization of GRB991226
  19. GRB 991216: J band spectrophotometry
  20. GRB 991216: Detection of the Host and/or Absorber Galaxy
  21. Single IPN error box for GRB991221
  22. GRB 991216 RXTE ASM Observations
  23. IPN error box for GRB991216
  24. Lowell/Perkins observation of GRB 991216
  25. GRB 991217 (SAX J2303.2+0015) Optical observations
  26. GRB991217/SAX J2303.2+0015, optical observations
  27. Chandra observation of the X-ray afterglow of GRB991216
  28. GRB 991216, optical observations
  29. GRB 991216 Optical Observations
  30. GRB 991216 Optical spectroscopy/imaging
  31. VLT spectra of GRB991216
  32. GRB991216 Optical and IR observations
  33. SAX J2303.2+0015 Optical observations
  34. IR observations of GRB991216
  35. GRB991216 radio observations
  36. GRB 991217 (SAX J2303.2+0015) Optical observations
  37. GRB991216 radio observations
  38. Lowell/Perkins observation of GRB 991216
  39. GRB991216, optical observations
  40. Refined IPN localization of GRB991216
  41. GRB 991216 Radio Observations
  42. GRB 991208 Keck Spectroscopy
  43. GRB 991208 Infrared Detection
  44. GRB991216
  45. GRB 991216--Summary of RXTE Observations
  46. GRB 991216 Optical Observations
  47. GRB 991216, optical observations
  48. GRB 991208 SAO-RAS Spectroscopy
  49. GRB 991216, Optical Transient
  50. GRB 991216, Optical Afterglow
  51. GRB991216 ('Beethoven Burst') B, R, and K Observations
  52. GRB 991216: Comparison with DPOSS images
  53. GRB 991208 optical observations
  54. Lowell/Perkins observation of GRB 991216
  55. GRB 991216 Optical Observation
  56. GRB 991208 Keck Spectroscopy
  57. R-band Observations of GRB991208 at TNG
  58. GRB991208, optical observations
  59. GRB 991208 Keck Spectroscopy
  60. GRB991208 - millimeter detection
  61. GRB 991208, Optical Observation
  62. GRB991208 15-GHz observations
  63. GRB991208, optical observations
  64. GRB 991208 - OVRO detection
  65. GRB 991208 Optical Decay
  66. GRB 991208 optical observations
  67. GRB 991208 optical observations
  68. GRB 991208: Radio Observations
  69. Optical Observations of GRB991105
  70. GRB991106: BeppoSAX/BATSE results
  71. GRB 991106, optical observations
  72. GRB991106, near-infrared observations
  73. BeppoSAX NFI Observation of GRB991106
  74. GRB 991106, radio observations
  75. GRB 991105: BATSE Observations
  76. IPN localization of GRB991105
  77. GRB 991106 Optical Observations
  78. GRB 991105, optical observations
  79. GRB991106, optical observation at SAO-RAS
  80. GRB 991106, LOTIS Optical Observations
  81. GRB 991106, optical observations
  82. Revised BeppoSAX WFC position of GRB991105
  83. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  84. GRB 991014, Optical Observations
  85. GRB 991014 - BeppoSAX NFI observations
  86. GRB 991014, Optical Observations
  87. GRB 991014, Optical Observations
  88. GRB 991014, optical observations
  89. Super-LOTIS optical observation of GRB991014
  90. IPN/NFI error box for GRB991014
  91. IPN localization of GRB991014 - CORRECTION
  92. IPN localization of GRB991014
  93. GRB 990915 optical observations
  94. GRB 990907 optical observations
  95. Optical Observations of GRB990907
  96. IPN error box for GRB990915 (=BATSE 7766)
  97. IPN localization of BATSE #7766 (GRB990915)
  98. GRB990907: BeppoSAX follow up and X-ray afterglow
  99. GRB990907 and 990908
  100. IPN localization of GRB990907

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