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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"

32489 results found.

  1. GRB 000131 Optical Observations
  2. GRB000126 Optical Observations
  3. GRB 991208, radio observations
  4. BATSE+IPN location of GRB000131
  5. GRB 000126, optical observations
  6. GRB000126, optical observations
  7. BATSE location of GRB000126
  8. GRB 000115 Optical observations
  9. BATSE Observations of GRB000115
  10. Correction to GCN 520 (IPN annulus for GRB000115)
  11. IPN annulus for GRB000115
  12. GRB991216, UBVRIJHK field photometry
  13. GRB991216 late optical observation
  14. Single IPN error box for GRB991229
  15. GCN resumes full operations
  16. GRB 991216 VLBA Observations
  17. BEPPOSAX GRBM Localization of GRB991226
  18. GRB 991216: J band spectrophotometry
  19. GRB 991216: Detection of the Host and/or Absorber Galaxy
  20. Single IPN error box for GRB991221
  21. GRB 991216 RXTE ASM Observations
  22. IPN error box for GRB991216
  23. Lowell/Perkins observation of GRB 991216
  24. GRB 991217 (SAX J2303.2+0015) Optical observations
  25. GRB991217/SAX J2303.2+0015, optical observations
  26. Chandra observation of the X-ray afterglow of GRB991216
  27. GRB 991216, optical observations
  28. GRB 991216 Optical Observations
  29. GRB 991216 Optical spectroscopy/imaging
  30. VLT spectra of GRB991216
  31. GRB991216 Optical and IR observations
  32. SAX J2303.2+0015 Optical observations
  33. IR observations of GRB991216
  34. GRB991216 radio observations
  35. GRB 991217 (SAX J2303.2+0015) Optical observations
  36. GRB991216 radio observations
  37. Lowell/Perkins observation of GRB 991216
  38. GRB991216, optical observations
  39. Refined IPN localization of GRB991216
  40. GRB 991216 Radio Observations
  41. GRB 991208 Keck Spectroscopy
  42. GRB 991208 Infrared Detection
  43. GRB991216
  44. GRB 991216--Summary of RXTE Observations
  45. GRB 991216 Optical Observations
  46. GRB 991216, optical observations
  47. GRB 991208 SAO-RAS Spectroscopy
  48. GRB 991216, Optical Transient
  49. GRB 991216, Optical Afterglow
  50. GRB991216 ('Beethoven Burst') B, R, and K Observations
  51. GRB 991216: Comparison with DPOSS images
  52. GRB 991208 optical observations
  53. Lowell/Perkins observation of GRB 991216
  54. GRB 991216 Optical Observation
  55. GRB 991208 Keck Spectroscopy
  56. R-band Observations of GRB991208 at TNG
  57. GRB991208, optical observations
  58. GRB 991208 Keck Spectroscopy
  59. GRB991208 - millimeter detection
  60. GRB 991208, Optical Observation
  61. GRB991208 15-GHz observations
  62. GRB991208, optical observations
  63. GRB 991208 - OVRO detection
  64. GRB 991208 Optical Decay
  65. GRB 991208 optical observations
  66. GRB 991208 optical observations
  67. GRB 991208: Radio Observations
  68. Optical Observations of GRB991105
  69. GRB991106: BeppoSAX/BATSE results
  70. GRB 991106, optical observations
  71. GRB991106, near-infrared observations
  72. BeppoSAX NFI Observation of GRB991106
  73. GRB 991106, radio observations
  74. GRB 991105: BATSE Observations
  75. IPN localization of GRB991105
  76. GRB 991106 Optical Observations
  77. GRB 991105, optical observations
  78. GRB991106, optical observation at SAO-RAS
  79. GRB 991106, LOTIS Optical Observations
  80. GRB 991106, optical observations
  81. Revised BeppoSAX WFC position of GRB991105
  82. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  83. GRB 991014, Optical Observations
  84. GRB 991014 - BeppoSAX NFI observations
  85. GRB 991014, Optical Observations
  86. GRB 991014, Optical Observations
  87. GRB 991014, optical observations
  88. Super-LOTIS optical observation of GRB991014
  89. IPN/NFI error box for GRB991014
  90. IPN localization of GRB991014 - CORRECTION
  91. IPN localization of GRB991014
  92. GRB 990915 optical observations
  93. GRB 990907 optical observations
  94. Optical Observations of GRB990907
  95. IPN error box for GRB990915 (=BATSE 7766)
  96. IPN localization of BATSE #7766 (GRB990915)
  97. GRB990907: BeppoSAX follow up and X-ray afterglow
  98. GRB990907 and 990908
  99. IPN localization of GRB990907
  100. GRB 990712 Late Optical Decay and Host Galaxy

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