Stanza 4 Summary

Get out the microscope, because we’re going through this poem line-by-line.

And now, as the night was senescent

Alright – things get a little weird here, so stick with us (actually, maybe they've been weird for a while, but he definitely kicks things up a notch here).
There's a big vocab word in this line: "senescent," which means aging, reaching the end of life. So all he's saying is that the night is ending, getting closer to morning.

And star-dials pointed to morn—

The "star-dials" is most likely a poetic way of referring to the great wheel of stars that move over your head all night. If you knew what you were doing, you could tell the time by the position of the stars, and know when dawn was coming.

As the star-dials hinted of morn—

Here's another almost-repetition, echoing line 31. The suspense of breaking dawn builds over these lines, and we can feel that something is about to happen.

At the end of our path a liquescent
And nebulous lustre was born,

Poe is getting extra-fancy with the vocabulary here. We'll break it down for you.
The speaker and his soul can see something at the end of their path. He calls is "a liquescent/ and nebulous lustre."
A "lustre" is a light, a radiance.
"Nebulous" means misty or cloudy.
"Liquescent" means something that moves like a liquid, melting and flowing and pouring.
Putting it all together, the speaker and his soul are looking down the trail at a misty light that looks like it's melting across the landscape.

Out of which a miraculous crescent
Arose with a duplicate horn—

The speaker seems to be intentionally a bit mysterious here. He doesn't quite seem sure what he's looking at, and wants us to feel that sense of confusion and awe too.
A shape emerges from the light – a "miraculous crescent," with two horns on either end.
It might seem, from the description in these lines, that the speaker is looking at the moon. Based on what we'll read later, though, it's pretty clear that he's talking about the rising of the morning star, or Venus. Instead of telling us what he's seeing, though, he describes the experience of seeing it.

Astarte's bediamonded crescent
Distinct with its duplicate horn.

Now he tells us a little more about this miraculous shape. He refers to it as "Astarte's bediamonded crescent." This one takes a little looking up.
Astarte was a Phoenician goddess, associated with the planet Venus, and she was often depicted wearing a crown with two horns.
So basically this means that the speaker is watching a star come up. But how boring would it be if he just came out and said that? Instead we get this dramatic image of a mighty goddess exploding over the horizon, bathed in light and wearing a diamond crown. Cool, huh?