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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"

36681 results found.

  1. GRB 000301c: K' observations
  2. GRB000301C, optical R-band observations
  3. GRB000301c - R photometry and nearby faint source confirmation
  4. GRB 000301C, Optical Observation
  5. GRB 000301c: K' observations
  6. GRB 000301C Optical Observations
  7. GRB 000301C: K' Observations
  8. GRB000301C - Host galaxy not detected in R (?)
  9. GRB000301C optical observations
  10. GRB 000301c near-IR observations
  11. GRB 000301C, Optical Color
  12. GRB000301C, Optical Spectroscopy
  13. GRB 000301C, UBVRI field photometry
  14. GRB 000301C, Optical Observation
  15. GRB000301C 250 GHz detection
  16. GRB 000301C R-band observation
  17. GRB 000301C, Optical Observation
  18. GRB000301C, near-infrared observations (JHK' photometry)
  19. GRB 000301C: OT confirmed
  20. GRB000301c optical observations
  21. GRB 000301A, Radio Observations
  22. GRB000301C, optical observations
  23. GRB000301c, near-infrared observations
  24. GRB000301C
  25. GRB 000301C : Optical Candidate
  26. GRB000301C: RXTE/ASM and IPN localizations
  27. GRB000226 [IPN Position]
  28. HST Observations of GRB 990712
  29. GRB 000214 near-IR observations
  30. GRB 000115 Optical observations
  31. GRB 000214, Radio Observations
  32. GRB 000214 ``Valentine's Day Burst'': BeppoSAX NFI Observation
  33. GRB 000115, BVRI field photometry
  34. IPN annulus for GRB000214
  35. BATSE GRB trigger criterion changed
  36. GRB000210 X-ray afterglow
  37. GRB000214: X-ray afterglow candidate
  38. BeppoSAX GRB000214 ("S. Valentine's day GRB")
  39. GRB 000210: BATSE Observations
  40. Optical observations of the Chandra X-ray source for GRB000210
  41. Chandra Observations of GRB000210 X-ray Afterglow
  42. IPN triangulation of GRB000210
  43. GRB 000201: TAROT optical observations
  44. GRB 000131 Optical Observations
  45. GRB000126 Optical Observations
  46. BATSE GRB trigger criteria changed
  47. GRB 991208, radio observations
  48. BATSE+IPN location of GRB000131
  49. IPN localization of GRB000131
  50. GRB 000126, optical observations
  51. GRB000126, optical observations
  52. BATSE location of GRB000126
  53. IPN localization of GRB000126
  54. GRB 000115 Optical observations
  55. BATSE Observations of GRB000115
  56. Second RXTE Observation of GRB 000115
  57. GRB991216, UBVRIJHK field photometry
  58. Single IPN error box for GRB991229
  59. GRB 991216 VLBA Observations
  60. BEPPOSAX GRBM Localization of GRB991226
  61. IPN error boxes for GRB991229
  62. GRB 991216: J band spectrophotometry
  63. GRB 991216: Detection of the Host and/or Absorber Galaxy
  64. IPN localization of GRB991226
  65. Single IPN error box for GRB991221
  66. IPN error boxes for GRB991221
  67. GRB 991216 RXTE ASM Observations
  68. IPN error box for GRB991216
  69. GRB 991216: Updated BATSE parameters
  70. Lowell/Perkins observation of GRB 991216
  71. GRB 991217 (SAX J2303.2+0015) Optical observations
  72. Chandra observation of the X-ray afterglow of GRB991216
  73. GRB 991216, optical observations
  74. GRB 991216 Optical Observations
  75. GRB 991216 Optical spectroscopy/imaging
  76. K observations of GRB991216
  77. GRB 991217 (SAX J2303.2+0015) Optical observations
  78. GRB991216 Spectroscopy
  79. Lowell/Perkins observation of GRB 991216
  80. GRB991216, optical observations
  81. Refined IPN localization of GRB991216
  82. GRB 991216 Radio Observations
  83. GRB 991217
  84. GRB 991208 Keck Spectroscopy
  85. GRB 991208 Infrared Detection
  86. GRB 991216--Summary of RXTE Observations
  87. GRB 991216 Optical Observations
  88. GRB 991216, optical observations
  89. GRB 991208 SAO-RAS Spectroscopy
  90. SAX J2303.2+0015: an x-ray/GRB?
  91. GRB 991216, Optical Transient
  92. GRB 991216, Optical Afterglow
  93. GRB 991216: Comparison with DPOSS images
  94. GRB 991208 optical observations
  95. Lowell/Perkins observation of GRB 991216
  96. GRB 991216 Optical Observation
  97. GRB 991208 Keck Spectroscopy
  98. GRB 991216: Extremely bright BATSE burst
  99. GRB991208, optical observations
  100. GRB 991208 Keck Spectroscopy

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