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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"

35942 results found.

  1. Optical observations of the Chandra X-ray source for GRB000210
  2. Chandra Observations of GRB000210 X-ray Afterglow
  3. IPN triangulation of GRB000210
  4. GRB 000201: TAROT optical observations
  5. GRB 000131 Optical Observations
  6. GRB000126 Optical Observations
  7. BATSE GRB trigger criteria changed
  8. GRB 991208, radio observations
  9. BATSE+IPN location of GRB000131
  10. IPN localization of GRB000131
  11. GRB 000126, optical observations
  12. GRB000126, optical observations
  13. BATSE location of GRB000126
  14. IPN localization of GRB000126
  15. GRB 000115 Optical observations
  16. BATSE Observations of GRB000115
  17. Second RXTE Observation of GRB 000115
  18. GRB991216, UBVRIJHK field photometry
  19. Single IPN error box for GRB991229
  20. GRB 991216 VLBA Observations
  21. BEPPOSAX GRBM Localization of GRB991226
  22. IPN error boxes for GRB991229
  23. GRB 991216: J band spectrophotometry
  24. GRB 991216: Detection of the Host and/or Absorber Galaxy
  25. IPN localization of GRB991226
  26. Single IPN error box for GRB991221
  27. IPN error boxes for GRB991221
  28. GRB 991216 RXTE ASM Observations
  29. IPN error box for GRB991216
  30. GRB 991216: Updated BATSE parameters
  31. Lowell/Perkins observation of GRB 991216
  32. GRB 991217 (SAX J2303.2+0015) Optical observations
  33. Chandra observation of the X-ray afterglow of GRB991216
  34. GRB 991216, optical observations
  35. GRB 991216 Optical Observations
  36. GRB 991216 Optical spectroscopy/imaging
  37. K observations of GRB991216
  38. GRB 991217 (SAX J2303.2+0015) Optical observations
  39. GRB991216 Spectroscopy
  40. Lowell/Perkins observation of GRB 991216
  41. GRB991216, optical observations
  42. Refined IPN localization of GRB991216
  43. GRB 991216 Radio Observations
  44. GRB 991217
  45. GRB 991208 Keck Spectroscopy
  46. GRB 991208 Infrared Detection
  47. GRB 991216--Summary of RXTE Observations
  48. GRB 991216 Optical Observations
  49. GRB 991216, optical observations
  50. GRB 991208 SAO-RAS Spectroscopy
  51. SAX J2303.2+0015: an x-ray/GRB?
  52. GRB 991216, Optical Transient
  53. GRB 991216, Optical Afterglow
  54. GRB 991216: Comparison with DPOSS images
  55. GRB 991208 optical observations
  56. Lowell/Perkins observation of GRB 991216
  57. GRB 991216 Optical Observation
  58. GRB 991208 Keck Spectroscopy
  59. GRB 991216: Extremely bright BATSE burst
  60. GRB991208, optical observations
  61. GRB 991208 Keck Spectroscopy
  62. GRB991208 - millimeter detection
  63. GRB 991208, Optical Observation
  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. IPN localization of GRB991208
  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. GRB991106: the first BeppoSAX short GRB detection?
  77. GRB 991105: BATSE Observations
  78. IPN localization of GRB991105
  79. GRB 991106 Optical Observations
  80. GRB 991105, optical observations
  81. GRB991106, optical observation at SAO-RAS
  82. GRB 991106, LOTIS Optical Observations
  83. GRB 991106, optical observations
  84. BeppoSAX GRB Alert: GRB991106
  85. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  86. GRB ALERT: GRB991105
  87. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  88. GRB 991014, Optical Observations
  89. GRB 991014 - BeppoSAX NFI observations
  90. GRB 991014, Optical Observations
  91. GRB 991014, radio observations
  92. GRB991014 BATSE Observations
  93. GRB 991014, Optical Observations
  94. GRB 991014, optical observations
  95. Super-LOTIS optical observation of GRB991014
  96. IPN/NFI error box for GRB991014
  97. IPN localization of GRB991014 - CORRECTION
  98. IPN localization of GRB991014
  99. BeppoSAX ALERT: GRB991014
  100. GRB 990915 optical observations

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