Question: Ursa Minor is one of the constellations based upon what?
Context: In modern astronomy, the sky (celestial sphere) is divided into 88 regions called constellations, generally based on the asterisms (which are also called "constellations") of Greek and Roman mythology.  Those along the ecliptic are the constellations of the zodiac. The Four Advisors () is a traditional Chinese asterism found in the Purple Forbidden enclosure ().  It consists of four stars found in the modern constellations of Ursa Minor and Camelopardalis and represents the four assistants of ancient emperors.  During the Qing dynasty, a star from the constellation Draco was added to the asterism. The Ursa Minor Dwarf is a dwarf spheroidal galaxy, discovered by A.G. Wilson of the Lowell Observatory, in the United States, during the Palomar Sky Survey in 1955.  It appears in the Ursa Minor constellation, and is a satellite galaxy of the Milky Way.  The galaxy consists mainly of older stars and seems to house little to no ongoing star formation.  Its centre is around 225,000 light years distant from Earth. Ursa Minor (Latin: "Lesser Bear", contrasting with Ursa Major), also known as the Little Bear, is a constellation in the Northern Sky.  Like the Great Bear, the tail of the Little Bear may also be seen as the handle of a ladle, hence the North American name, Little Dipper: seven stars with four in its bowl like its partner the Big Dipper.  It was one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and remains one of the 88 modern constellations.  Ursa Minor has traditionally been important for navigation, particularly by mariners, because of Polaris being the North Star. Northern Pole (北极 in Simplified Chinese, "běi jí" in Pinyin) is a traditional Chinese asterism found in the Purple Forbidden enclosure (紫微垣 in Simplified Chinese, "zǐ wēi yuán" in Pinyin).  It consists of five stars found in the modern constellations of Ursa Minor and Camelopardalis and represents the five stars of the North Pole.  During the Qing dynasty, a total of four stars from the constellation Ursa Minor was added to the asterism. Ursa Major ( ; also known as the Great Bear) is a constellation in the northern sky, whose associated mythology likely dates back into prehistory.  Its Latin name means "greater (or larger) she-bear", standing as a reference to and in direct contrast with nearby Ursa Minor, the lesser bear.  In antiquity, it was one of the original 48 constellations listed by Ptolemy (2nd century AD), and is now the third largest constellation of the 88 modern constellations. Eta Ursae Minoris, Latinized from η Ursae Minoris, is a yellow-white hued star in the northern circumpolar constellation of Ursa Minor.  It has been called Anwar al Farkadain, from the Arabic نور الفرقدين "’anwar al-farqadayn", meaning "the brighter of the two calves".  It is then paired with ζ Ursae Minoris as Ahfa al Farkadain, "the dimmer of the two calves".  The names may originally refer to a pair of Ibexes, and are more properly applied to β UMi and γ UMi respectively, the brighter two stars in the rectangle of Ursa Minor. Epsilon Ursae Minoris (ε Ursae Minoris) is a binary star system in the northern circumpolar constellation of Ursa Minor.  It is visible to the naked eye with a combined apparent visual magnitude of 4.19.  Based upon an annual parallax shift of 10.73 mas as seen from the Earth, it is located around 300 light years from the Sun.  The pair are drawing nearer to the Sun with a radial velocity of −10.57 km/s. Beta Ursae Minoris (β Ursae Minoris, abbreviated Beta UMi, β UMi), also named Kochab, is the brightest star in the bowl of the Little Dipper asterism (which is part of the constellation of Ursa Minor), and only slightly fainter than Polaris, the northern pole star and brightest star in Ursa Minor.  Kochab is 16 degrees from Polaris and has an apparent visual magnitude of 2.08.  The distance to this star from the Sun can be deduced from the parallax measurements made during the Hipparcos mission, yielding a value of 130.9 ly . Ursa Minor Cave is part of Sequoia National Park, a naturally formed system of caves in California's Sierra Nevada.  The cave was discovered in August 2006 by four cave explorers from the Cave Research Foundation who found a softball-sized hole on a cliff face in the mountains.  After widening the hole to allow for human entry, the explorers discovered one of the most spectacular caves in the western United States.  The cave has since been named "Ursa Minor," because of the large bear skeleton found in the cave.
Answer: asterisms