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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"

39175 results found.

  1. GRB 000301C, Optical Observation
  2. GRB000301C 250 GHz detection
  3. GRB 000301C R-band observation
  4. GRB 000301C, Optical Observation
  5. GRB000301C, near-infrared observations (JHK' photometry)
  6. GRB 000301C: OT confirmed
  7. GRB000301c optical observations
  8. GRB 000301A, Radio Observations
  9. GRB000301C, optical observations
  10. GRB000301c, near-infrared observations
  11. GRB000301C
  12. GRB 000301C : Optical Candidate
  13. GRB000301C: RXTE/ASM and IPN localizations
  14. GRB000226 [IPN Position]
  15. HST Observations of GRB 990712
  16. GRB 000214 near-IR observations
  17. GRB 000115 Optical observations
  18. GRB 000214, Radio Observations
  19. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  20. GRB 000115, BVRI field photometry
  21. IPN annulus for GRB000214
  22. BATSE GRB trigger criterion changed
  23. GRB000210 X-ray afterglow
  24. GRB000214: X-ray afterglow candidate
  25. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  26. GRB 000210: BATSE Observations
  27. Correction to Chandra Position of GRB000210 afterglow
  28. Optical observations of the Chandra X-ray source for GRB000210
  29. Optical candidate for GRB000210
  30. Chandra Observations of GRB000210 X-ray Afterglow
  31. IPN triangulation of GRB000210
  32. GRB 000201: TAROT optical observations
  33. GRB 000131 Optical Observations
  34. GRB000126 Optical Observations
  35. BATSE GRB trigger criteria changed
  36. GRB 991208, radio observations
  37. BATSE+IPN location of GRB000131
  38. IPN localization of GRB000131
  39. GRB 000126, optical observations
  40. GRB000126, optical observations
  41. BATSE location of GRB000126
  42. IPN localization of GRB000126
  43. GRB 000115 Optical observations
  44. BATSE Observations of GRB000115
  45. Second RXTE Observation of GRB 000115
  46. GRB991216, UBVRIJHK field photometry
  47. Single IPN error box for GRB991229
  48. GRB 991216 VLBA Observations
  49. BEPPOSAX GRBM Localization of GRB991226
  50. IPN error boxes for GRB991229
  51. GRB 991216: J band spectrophotometry
  52. GRB 991216: Detection of the Host and/or Absorber Galaxy
  53. IPN localization of GRB991226
  54. Single IPN error box for GRB991221
  55. IPN error boxes for GRB991221
  56. GRB 991216 RXTE ASM Observations
  57. IPN error box for GRB991216
  58. GRB 991216: Updated BATSE parameters
  59. Lowell/Perkins observation of GRB 991216
  60. GRB 991217 (SAX J2303.2+0015) Optical observations
  61. Chandra observation of the X-ray afterglow of GRB991216
  62. GRB 991216, optical observations
  63. GRB 991216 Optical Observations
  64. GRB 991216 Optical spectroscopy/imaging
  65. K observations of GRB991216
  66. GRB 991217 (SAX J2303.2+0015) Optical observations
  67. GRB991216 Spectroscopy
  68. Lowell/Perkins observation of GRB 991216
  69. GRB991216, optical observations
  70. Refined IPN localization of GRB991216
  71. GRB 991216 Radio Observations
  72. GRB 991217
  73. GRB 991208 Keck Spectroscopy
  74. GRB 991208 Infrared Detection
  75. GRB 991216--Summary of RXTE Observations
  76. GRB 991216 Optical Observations
  77. GRB 991216, optical observations
  78. GRB 991208 SAO-RAS Spectroscopy
  79. SAX J2303.2+0015: an x-ray/GRB?
  80. GRB 991216, Optical Transient
  81. GRB 991216, Optical Afterglow
  82. GRB 991216: Comparison with DPOSS images
  83. GRB 991208 optical observations
  84. Lowell/Perkins observation of GRB 991216
  85. GRB 991216 Optical Observation
  86. GRB 991208 Keck Spectroscopy
  87. GRB 991216: Extremely bright BATSE burst
  88. GRB991208, optical observations
  89. GRB 991208 Keck Spectroscopy
  90. GRB991208 - millimeter detection
  91. GRB 991208, Optical Observation
  92. GRB 991208 - OVRO detection
  93. GRB 991208 Optical Decay
  94. GRB 991208 optical observations
  95. GRB 991208 optical observations
  96. GRB 991208: Radio Observations
  97. IPN localization of GRB991208
  98. Optical Observations of GRB991105
  99. GRB991106: BeppoSAX/BATSE results
  100. GRB 991106, optical observations

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