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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"

41684 results found.

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

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