Yeah, no one knows for sure just what really took place. There is an incredible amount of artistic license use, as I will call it, surrounding the Christmas story. There is strong evidence that the manger birth wasn't in the winter since shepherds aren't watching over sheep in the field at that time.
The Josephus account of Herod's demise gives some interesting clues and I think most favor a 4BCE birth event.
The three magi -- it is assumed there were three since there were three gifts presented -- were likely somewhat wealthy Persian astrologers or very active amateur astrologers (borrowing from those here who appreciate amateur astronomers). Something inspired them to saddle-up there camels and make what was likely a fairly long trip.
Aries is one of the more popular constellations assigned to Judea, though there are a few others, apparently.
So, as to what may have happened that triggered this inspiration, here is a slightly abbreviated list of events that I found using Starry Night Pro from a few years ago. They are based on observations from Baghdad...
Jan. 1: Jupiter & Saturn close in Pisces
Jan. 23: Saturn equidistant between Jupiter and Moon in Pisces (pointing to Aries?)
Feb. 20: Mars, Jupiter, Saturn, and new Moon all within about 3 deg. radius
In Pisces at 7pm on western horizon
Mar. 4: Jupiter and Mars conjunction at sunset
Horizontal alignment with Saturn directly below
Mar. 19: Lunar occulation of Saturn (not visible, too close to Sun and below horizon)
Mar. 24: Venus and Saturn conjunction at dawn in Pisces
Apr. 16: Lunar occulation of Saturn, 12:50 pm in Pisces. (not visible, daytime)
Apr. 17: Lunar occulation of Jupiter, about 12:45 pm (daytime)
Apr. 18: Annular Solar eclipse (not visible from Middle East)
Apr. 24: Saturn and Venus only 42 arcmin separation in Pisces
Seen only briefly around 4:30 am on horizon (4 deg alt.)
May 8: Conjunction of Jupiter and Venus (34 arcmin in Aries).
Visible only on horizon from 4 to 5:30 am
May 13: Lunar occulation of Saturn in Pisces (not visible from Middle East)
11 pm but 46 deg below horizon. Venus and Jupiter reasonably close by.
May 15: Lunar conjunction of Jupiter in Aries (< 6 arcminutes)
Visible about one and one-half hours before conjunction.
Venus-Jupiter-Moon-Saturn aligned (Aries region)
May 16: Venus and very thin crescent Moon proximity (3 deg) in Taurus
Seen only briefly about 4:30 am
Jul. 2: Venus & Mars conjunction at dusk
Jul. 10: Mercury & Venus conjunction at dusk (Mars nearby)
Jul. 22: Saturn begins retrograde between Cetus and Aries
Aug. 22: Jupiter begins retrograde back into Aries
Sep. 2: Mars visible within 50 arcminutes of Regulus at 4:30am in Leo
Sep 14: Lunar occulation of Venus (far below horizon, not visible)
Nov. 7: Mars about 2 deg. from Moon when it rises in East (2 am in Virgo)
5 BC: [Most activity too close to Sun]
Mar. 11: Lunar conjunction of Venus with Jupiter and Pleiades very close
Region between Taurus and Aries asterisms.
Actual conjunction only 1 arcmin separation but well below horizon
Mar. 23: Total Lunar eclipse, 9:30 pm, 38 deg. alt., in Virgo
Sep. 15: Total Lunar eclipse, 11:20 pm, 50 deg. alt., in Pisces
4BC: [Most activity too close to Sun]
Jan. 30: Lunar conjunction with Mars in Pisces
30 arcminutes at 3pm, 1 deg. at 6 pm.
Mar. 6 & 7: Conjunction of Saturn and Mars (~ 2 deg)
Seen near western horizon around 7:30 pm, in Aries
Mar 13: Lunar eclipse (1/3 partial umbra passage), 3:30 am in Virgo (33 deg alt.)
May 9: Conjunction of Saturn and Mercury, dawn, in Taurus
May 17: Conjunction of Mars and Venus at dusk near horizon (Jupiter nearby)
May 23: Conjunction of Venus and Jupiter at dusk near horizon in Gemini
Sep 5: Lunar eclipse (2/3 umbral passage), but at 2:15 pm (daytime) and well below horizon
Whatever triggered the travels to Jerusalem, the capital, to begin asking around about the new king, it certainly could have been one of those events listed. Thereafter, the "star" must be considered something abnormal.
No natural light from the celestial sky can plausibly pin-point a house, but a supernatural one could and it would be appropriate given the significance of the event. Of course, this becomes a matter of faith since we just stepped out of the realm of science.
There is a slight possibility, however, that a moon beam through a fortuitous and unusual hole in the cloud cover may have guided the magi. Such things aren't that unusual but it would be if the light was upon only one house. It wouldn't have lasted long but they knew to go to Bethlehem so they may have been nearby or already in town when that happened. This is just speculation, of course.