Scutum is a small constellation introduced in the seventeenth century. Its name is Latin for a shield. It is the fifth-smallest constellation in the sky and was originally introduced by the Polish astronomer Johannes Hevelius in the 17th century. Hevelius named it Scutum Sobiescianum, Shield of Sobieski, in honour of the Polish King Jan III Sobieski, who had been victorious in the Battle of Vienna in 1683. Hevelius created the constellation a year later to commemorate the event, and the name was eventually simplified to Scutum. Scutum is the 84th constellation in size, occupying an area of only 109 square degrees. It is located in the fourth quadrant of the southern hemisphere and can be seen at latitudes between +80° and -90°. The neighbouring constellations are Aquila, Sagittarius and Serpens Cauda. Scutum does not have any stars brighter than magnitude 3.00 or located within 10 parsecs (32.6 light years) of Earth. Scutum belongs to the Hercules family of constellations, along with Aquila, Ara, Centaurus, Corona Australis, Corvus, Crater, Crux, Cygnus, Hercules, Hydra, Lupus, Lyra, Ophiuchus, Sagitta, Sextans, Serpens, Triangulum Australe and Vulpecula.
Scutum is not a bright constellation, with the brightest star, Alpha Scuti is the brightest star in the constellation. It is an orange giant with the stellar classification of K2III. It has an apparent magnitude of 3.85 and is approximately 174 light years distant from Earth. The star used to belong to Aquila constellation and was previously designated 1 Aquilae. It is a known variable star, with its brightness varying by about 10 per cent. Alpha Scuti is 132 times more luminous than the Sun and has a mass 1.7 times solar. It is believed to be at least 2 billion years old. Beta Scuti is the second brightest, followed by Delta Scuti. Beta Scuti has an apparent magnitude of 4.22 and is approximately 690 light years distant from the solar system. It is a yellow bright giant star with the stellar classification G5II, about 1,270 times more luminous than the Sun. The star used to be known as 6 Aquilae. Delta Scuti is a bluish white giant star, which is now coming at the direction of the Solar System. Within 1.3 million years it will come as close to 10 light years from Earth, and will be much brighter than Sirius by that time. UY Scuti is a red supergiant pulsating variable star and is also one of the largest stars currently known with a radius over 1,000 times that of the Sun.
Although not a large constellation, Scutum contains several open clusters, as well as a globular cluster and a planetary nebula. The two best known deep sky objects in Scutum are M11 (the Wild Duck Cluster) and the open cluster M26 (NGC 6694). The globular cluster NGC 6712 and the planetary nebula IC 1295 can be found in the eastern part of the constellation. The most prominent open cluster in Scutum is the Wild Duck Cluster, M11. The Wild Duck Cluster was discovered by the German astronomer Gottfried Kirch in 1681, and included in Messier’s catalogue in 1764. It was named by William Henry Smyth in 1844 for its resemblance in the eyepiece to a flock of ducks in flight. The cluster, 6200 light-years from Earth and 20 light-years in diameter, contains approximately 2,900 stars, making it a particularly rich cluster. It is 220 million years old and is an open cluster with an apparent magnitude of 6.3. Messier 26 is another open cluster in Scutum. It has an apparent magnitude of 8.0 and is approximately 5,000 light years distant from Earth. The cluster was discovered by Charles Messier in 1764 and subsequently included in his catalogue. M26 is about 22 light-years across and believed to be about 89 million years old. The brightest star in the cluster has an apparent magnitude of 11.9. NGC 6712 is a globular cluster in Scutum. It has a visual magnitude of 8.69 and is about 22,500 light years distant from the solar system. The cluster was probably discovered by the French astronomer Le Gentil in July 1749. Le Gentil described the objects as a “true nebula.” NGC 6712 was later independently discovered by the German-British astronomer William Herschel on June 16, 1784. Herschel classified the cluster as a round nebula. It was John Herschel who was the first to describe the object as a globular star cluster in the 1830s. IC 1295 is a planetary nebula in Scutum constellation. It has an apparent magnitude of 12.7 and is about 3,300 light years distant from Earth. The central star is a white dwarf currently in the process of shedding its outer layers. RSGC1 is an open cluster in the Milky Way Galaxy, approximately 22,000 light-years away in the direction of Scutum constellation. It is a young, massive star cluster with 12 red supergiant stars, one yellow hypergiant, and one intermediate. The cluster cannot be seen in visible light; it was discovered in 2006 using data from several infrared surveys. It is believed to be 10-14 million years old and is one of the most massive known clusters in our galaxy. Credits: Constellation Guide, Wikipedia.