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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"

32491 results found.

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

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