What celestial phenomenon causes the Hunter's Moon to often show a shorter delay between successive moonrises?

Answer

The Moon's path makes a narrow angle with the eastern horizon in mid-latitudes.

Around the time of the Harvest and Hunter's Moons, the moon's shallow angle relative to the eastern horizon causes moonrises to occur only about 30 minutes apart for several nights, instead of the average 50 minutes.

What celestial phenomenon causes the Hunter's Moon to often show a shorter delay between successive moonrises?
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