There are several objects you can try to pin from suburbia at this time of night and year when the Moon isn't up, as Ron mentions.
* Globular cluster 47Tuc, the second brightest GC in the sky, and a naked eye object, even from suburbia. It is also easy to resolve in a 4.5" scope like yours. Tip: be patient with 47 Tuc - it is a shy character. Concentrate you gaze just to one side of the GC, hold your gaze there, and suddenly, WOOSH, a myriad of thousands of tiny stars pop out! It really is a lovely effect,
* Globular Cluster NGC 362 - close to 47 Tuc, and also in Tucana. But 362 is a more typical GC, being just a fuzz ball. Makes for a good contrast between the two.
* Tarantula Nebula. The brightest nebula in the sky before M42 rises later on. Thing is, the Tarantula is in another galaxy altogether, not the Milky Way! The Tarantula is in the Large Magellanic Cloud. The LMC is a satellite galaxy of the MW, along with the Small Magellanic Cloud (47 Tuc sits to one side of the SMC, but has nothing to do with it). Both the LMC and SMC can be visible under urban skies, though it is getting more difficult every year. The Tarantula is also a naked eye object, but more so under dark skies. The Tarantula takes high magnification very well, and is very detailed.
* LMC and SMC. I already mentioned them above, but they also merit some exploration. The LMC being larger also has a wider range of objects, including open clusters, globular clusters, nebula and super nova remnants.
* Galaxy NGC 253. One of the brighter galaxies in the sky, though not a naked eye object. 253 is known as the Silver Dollar galaxy, and seen close to edge on, and sits in the constellation Sculptor.
* Andromeda Galaxy - Can be tough as it does not rise very high in the sky for us here in Oz. If seeing and transparency is favourable, it really is an enormous and gorgeous spectacle. Can be a naked eye object for us too.
* M33 Triangulum Galaxy. Can be a tough sucker for us. One of the few galaxies to show us a spiral structure, though might still require a larger aperture than 4.5" so see - but have a go. I saw M33 as an angel's breath faint naked eye object from Katoomba Airfield some time ago (Katoomba Airfield is 2 hours west of Sydney and sits at 1000m above sea level)
I'm sure other people will be able to add some more objects.
Happy hunting,
Mental.
