De Vaucouleurs Atlas Type: SA(s)cd
Telescope: 0.076-m Televue refr
North up , East left
Field Dimensions: 58.5 x 43.7 arcminutes
RC3 Type: SA(s)cd
RSA Type: Sc(s)II-III
Surface Brightness Range Displayed: 19.5-27.0 mag per square arcsec
Absolute Blue Magnitude: -18.9
Elmegreen Spiral Arm Class: AC 5
De Vaucouleurs Atlas Description:
M33 is a very good example of a nearby SA(s)cd type. The arms are ``massive ", and there is only a small core. The general surface brightness is low, and the galaxy is not as ``knotty" as NGC 2403 , which we interpret as somewhat later in type.
M33 has been the subject of many studies, mostly because, as a very late-type system, its morphology is dominated by young stars. M33 is so close to us that individual clusters and associations are resolvable with modern instrumentation, thus allowing studies of the star formation history of the system. An interesting recent finding is a large swath of carbon stars located outside the main two-armed inner spiral, detected on deep 2MASS JHKs images (Block et al. 2004b). The presence of these stars is suggested by Block et al. to be evidence that M33 has accreted low metallicity external gas within the past 2Gyr.