We present combined photometric and spectroscopic analyses of the southern binary star PU Pup.High-resolution spectra of this system were taken at the University of Canterbury Mt.John Observatory in the years 2008 and...We present combined photometric and spectroscopic analyses of the southern binary star PU Pup.High-resolution spectra of this system were taken at the University of Canterbury Mt.John Observatory in the years 2008 and again in 2014-2015.We find the light contribution of the secondary component to be only 2%of the total light of the system in optical wavelengths,resulting in a single-lined spectroscopic binary.Recent TESS data revealed grazing eclipses within the light minima,though the tidal distortion,examined also from Hipparcos data,remains the predominating light curve effect.Our model shows PU Pup to have the more massive primary relatively close to filling its Roche lobe.PU Pup is thus approaching the rare‘fast phase’of interactive(Case B)evolution.Our adopted absolute parameters are as follows:M_(1)=4.10(±0.20)M_(⊙),M_(2)=0.65(±0.05)M_(⊙),R_(1)=6.60(±0.30)R_(⊙),R_(2)=0.90(±0.10)R_(⊙);T_(1)=11500(±500)K,T_(2)=5000(±350)K;photometric distance=186(±20)pc,age=170(±20)Myr.The less-massive secondary component is found to be significantly oversized and overluminous compared to standard main sequence models.We discuss this discrepancy referring to heating from the reflection effect.展开更多
Study of QSOs is an important area of modern astronomy and astrophysics, and is very useful in understanding the origin, the structure and the evolution of the universe. So far more than 4000 QSOs have been discovered...Study of QSOs is an important area of modern astronomy and astrophysics, and is very useful in understanding the origin, the structure and the evolution of the universe. So far more than 4000 QSOs have been discovered by various means. From 1986, we began to make a systematic QSO survey of UKST 855 area with 36 square degrees by means of slitless spectra, whose center is at 10~h40~m+00°00′. The survey was completed recently.展开更多
The study of the prominence velocity field is important for understanding the formation and evolution. People have found the macroscopic flow of cool material moving along the prominence. Engvold reported the downward...The study of the prominence velocity field is important for understanding the formation and evolution. People have found the macroscopic flow of cool material moving along the prominence. Engvold reported the downward motion of展开更多
文摘We present combined photometric and spectroscopic analyses of the southern binary star PU Pup.High-resolution spectra of this system were taken at the University of Canterbury Mt.John Observatory in the years 2008 and again in 2014-2015.We find the light contribution of the secondary component to be only 2%of the total light of the system in optical wavelengths,resulting in a single-lined spectroscopic binary.Recent TESS data revealed grazing eclipses within the light minima,though the tidal distortion,examined also from Hipparcos data,remains the predominating light curve effect.Our model shows PU Pup to have the more massive primary relatively close to filling its Roche lobe.PU Pup is thus approaching the rare‘fast phase’of interactive(Case B)evolution.Our adopted absolute parameters are as follows:M_(1)=4.10(±0.20)M_(⊙),M_(2)=0.65(±0.05)M_(⊙),R_(1)=6.60(±0.30)R_(⊙),R_(2)=0.90(±0.10)R_(⊙);T_(1)=11500(±500)K,T_(2)=5000(±350)K;photometric distance=186(±20)pc,age=170(±20)Myr.The less-massive secondary component is found to be significantly oversized and overluminous compared to standard main sequence models.We discuss this discrepancy referring to heating from the reflection effect.
基金Project partly supported by the National Natural Science Foundation of China
文摘Study of QSOs is an important area of modern astronomy and astrophysics, and is very useful in understanding the origin, the structure and the evolution of the universe. So far more than 4000 QSOs have been discovered by various means. From 1986, we began to make a systematic QSO survey of UKST 855 area with 36 square degrees by means of slitless spectra, whose center is at 10~h40~m+00°00′. The survey was completed recently.
基金Project supported by the National Natural Science Foundation of China
文摘The study of the prominence velocity field is important for understanding the formation and evolution. People have found the macroscopic flow of cool material moving along the prominence. Engvold reported the downward motion of
