We have used optical V and R band observations from the Massive Compact Halo Object(MACHO) project on a sample of 59 quasars behind the Magellanic clouds to stu
The Magnetic Plage Strength Index(MPSI) and the Mount Wilson Sunspot Index(MWSI), which have been measured at Mount Wilson Observatory(MWO) since the 1970 s and
Abstract The issue of destroying small polycyclic aromatic hydrocarbon (PAH) par- ticles by radiation from AGNs is examined through optical narrow-emission line r
The fact that infrared ring nebulae(IRRNe) are frequently associated with HⅡ regions provides us with an opportunity to study dust at the interface between ion