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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"

38269 results found.

  1. GRB000301c optical observations
  2. GRB 000301A, Radio Observations
  3. GRB000301C, optical observations
  4. GRB000301c, near-infrared observations
  5. GRB000301C
  6. GRB 000301C : Optical Candidate
  7. GRB000301C: RXTE/ASM and IPN localizations
  8. GRB000226 [IPN Position]
  9. HST Observations of GRB 990712
  10. GRB 000214 near-IR observations
  11. GRB 000115 Optical observations
  12. GRB 000214, Radio Observations
  13. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  14. GRB 000115, BVRI field photometry
  15. IPN annulus for GRB000214
  16. BATSE GRB trigger criterion changed
  17. GRB000210 X-ray afterglow
  18. GRB000214: X-ray afterglow candidate
  19. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  20. GRB 000210: BATSE Observations
  21. Correction to Chandra Position of GRB000210 afterglow
  22. Optical observations of the Chandra X-ray source for GRB000210
  23. Optical candidate for GRB000210
  24. Chandra Observations of GRB000210 X-ray Afterglow
  25. IPN triangulation of GRB000210
  26. GRB 000201: TAROT optical observations
  27. GRB 000131 Optical Observations
  28. GRB000126 Optical Observations
  29. BATSE GRB trigger criteria changed
  30. GRB 991208, radio observations
  31. BATSE+IPN location of GRB000131
  32. IPN localization of GRB000131
  33. GRB 000126, optical observations
  34. GRB000126, optical observations
  35. BATSE location of GRB000126
  36. IPN localization of GRB000126
  37. GRB 000115 Optical observations
  38. BATSE Observations of GRB000115
  39. Second RXTE Observation of GRB 000115
  40. GRB991216, UBVRIJHK field photometry
  41. Single IPN error box for GRB991229
  42. GRB 991216 VLBA Observations
  43. BEPPOSAX GRBM Localization of GRB991226
  44. IPN error boxes for GRB991229
  45. GRB 991216: J band spectrophotometry
  46. GRB 991216: Detection of the Host and/or Absorber Galaxy
  47. IPN localization of GRB991226
  48. Single IPN error box for GRB991221
  49. IPN error boxes for GRB991221
  50. GRB 991216 RXTE ASM Observations
  51. IPN error box for GRB991216
  52. GRB 991216: Updated BATSE parameters
  53. Lowell/Perkins observation of GRB 991216
  54. GRB 991217 (SAX J2303.2+0015) Optical observations
  55. Chandra observation of the X-ray afterglow of GRB991216
  56. GRB 991216, optical observations
  57. GRB 991216 Optical Observations
  58. GRB 991216 Optical spectroscopy/imaging
  59. K observations of GRB991216
  60. GRB 991217 (SAX J2303.2+0015) Optical observations
  61. GRB991216 Spectroscopy
  62. Lowell/Perkins observation of GRB 991216
  63. GRB991216, optical observations
  64. Refined IPN localization of GRB991216
  65. GRB 991216 Radio Observations
  66. GRB 991217
  67. GRB 991208 Keck Spectroscopy
  68. GRB 991208 Infrared Detection
  69. GRB 991216--Summary of RXTE Observations
  70. GRB 991216 Optical Observations
  71. GRB 991216, optical observations
  72. GRB 991208 SAO-RAS Spectroscopy
  73. SAX J2303.2+0015: an x-ray/GRB?
  74. GRB 991216, Optical Transient
  75. GRB 991216, Optical Afterglow
  76. GRB 991216: Comparison with DPOSS images
  77. GRB 991208 optical observations
  78. Lowell/Perkins observation of GRB 991216
  79. GRB 991216 Optical Observation
  80. GRB 991208 Keck Spectroscopy
  81. GRB 991216: Extremely bright BATSE burst
  82. GRB991208, optical observations
  83. GRB 991208 Keck Spectroscopy
  84. GRB991208 - millimeter detection
  85. GRB 991208, Optical Observation
  86. GRB 991208 - OVRO detection
  87. GRB 991208 Optical Decay
  88. GRB 991208 optical observations
  89. GRB 991208 optical observations
  90. GRB 991208: Radio Observations
  91. IPN localization of GRB991208
  92. Optical Observations of GRB991105
  93. GRB991106: BeppoSAX/BATSE results
  94. GRB 991106, optical observations
  95. GRB991106, near-infrared observations
  96. BeppoSAX NFI Observation of GRB991106
  97. GRB 991106, radio observations
  98. GRB991106: the first BeppoSAX short GRB detection?
  99. GRB 991105: BATSE Observations
  100. IPN localization of GRB991105

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