A Few Rocks and a Star Trivia Quiz

Answer: Castor

While Castor appears as a single point of light to the naked eye, it is actually a sophisticated "sextuple" system located about 51 light-years away in the constellation Gemini. It consists of three pairs of binary stars all dancing in a complex gravitational ballet. The two brightest components are hot, white A-type stars, significantly more massive and luminous than our Sun.

Castor is named after one of the Great Twins of Greek mythology (the Dioscuri). Even in the sky, it sits right next to its stellar "twin", Pollux. While Pollux is a single orange giant, Castor's multi-star nature makes it a favorite for amateur astronomers; even a modest telescope can begin to resolve the distinct points of light that make up this stellar sibling rivalry.

Now, for the rocks, corundum is an incredibly hard aluminum oxide (similar to rubies and sapphires), while calcite is a common carbonate mineral famous for its double refraction. Carnelian is a brownish-red variety of chalcedony, prized since the age of antiquity as a gemstone.

Answer: Sirius

Sirius, known colloquially as the "Dog Star", is the brightest star in the night sky. Located a mere 8.6 light-years away in the constellation Canis Major, its brilliance isn't just due to its proximity, but also its intrinsic luminosity. It is about 25 times more luminous than our own Sun. Sirius is a binary system. It consists of Sirius A, a main-sequence star of spectral type A, and a faint white dwarf companion called Sirius B (nicknamed "the Pup", appropriately).

Sirius B was actually the first white dwarf ever discovered. It is an incredibly dense dead star which is roughly the mass of our Sun packed into a sphere the size of Earth. In ancient Egypt, the heliacal rising of Sirius (when it first became visible above the horizon at dawn) was used to predict the annual flooding of the Nile.

The other three rocks are closely related through the geological process of transformation. Shale is a fine-grained sedimentary rock formed from mud and clay, which, under intense heat and pressure, metamorphoses into slate. Finally, schist is a metamorphic rock recognizable by its wavy, layered appearance and a shimmering metallic sheen.

Answer: Betelgeuse

Betelgeuse is a red supergiant marking the "shoulder" of the constellation of the hunter, Orion. If you placed it at the center of our solar system, its surface would extend past the orbit of Mars and possibly even all the way to Jupiter. This star is a true heavy hitter, approximately 700 to 1,000 times larger than our Sun. Because it is so massive, it burns through its nuclear fuel at a furious pace; despite being much younger than the Sun, it is already nearing the end of its life.

Astronomers are watching Betelgeuse closely because it is a prime candidate for a supernova. When it finally runs out of fuel and collapses, it will create an explosion so bright it could be visible from Earth during the day for several weeks. It's a variable star, meaning its brightness fluctuates-sometimes dimming significantly as it ejects massive clouds of dust into space.

Beryl is a mineral that gives us gemstones like emerald and aquamarine. Bornite is an iridescent copper ore often called "peacock ore" for its colourful tarnish. Basalt is a dark, fine-grained volcanic rock that makes up most of the Earth's oceanic crust.

Answer: Gienah

Gienah is the brightest star in the small constellation of Corvus, the Crow. This star is actually referred to as Gienah Corvi to distinguish it from another star with the same name in the constellation Cygnus. Gienah is a blue-white giant, roughly four times more massive than our Sun and shining with about 350 times its luminosity. Located give-or-take 154 light-years away, it has exited the main sequence, meaning it has exhausted the hydrogen in its core and is beginning its transition into a much larger, cooler state. Interestingly, Gienah is a chemically interesting star. It is a rare type of chemically peculiar star which has an atmosphere with an unusually high abundance of elements like mercury, manganese, and even platinum.

Gypsum is a very soft sulfate mineral often used in drywall. Galena is the primary ore of lead, famous for its metallic luster and surprising heavy weight. Finally, granite is a common igneous rock that makes up much of the Earth's continental crust.

Answer: Procyon

Procyon is the brightest star in the constellation Canis Minor and the eighth-brightest star in the entire night sky. Its name translates from Greek as "before the dog", and is aptly named because it rises right before the Dog Star, Sirius. Just like its more famous neighbor, Procyon is a binary star system located very close to Earth. It is only about 11.5 light-years away. The primary star, Procyon A, is a white-hued main-sequence star that is roughly twice the size of our Sun and seven times more luminous.

Procyon A is currently in a fascinating transitional phase of its life; it is nearly finished fusing the hydrogen in its core and is beginning to expand into a subgiant. Its companion, Procyon B, is a faint white dwarf that is incredibly difficult to see without a powerful telescope because the glare from Procyon A overpowers and outshines it.

Peridot is a gem-quality version of the mineral olivine, often formed deep in the Earth's mantle, while pumice is a volcanic rock so porous and light that it can actually float on water. Pyrite, often called "fool's gold", is an iron sulfide mineral known for its metallic luster and cubic crystal habit. If you were a fool, you could have mistaken it for gold, especially in the California Gold Rush of 1849.

Answer: Spica

Spica is the brightest star in the constellation Virgo and the 16th brightest star in the night sky. Located approximately 250 light-years from Earth, it is a spectroscopic binary system. The two stars are so close together (only about 11 million miles apart) that they have distorted one another into egg-like shapes by their mutual gravity, which is immense. Their close proximity means that they have to rotate at a high speed. Indeed, their mutual orbit lasts a mere four days. Of the two, the primary star is a blue giant with a surface temperature of over 22,000 Kelvin. This makes it much hotter and more energetic than our Sun.

Because of its position near the ecliptic (the path the Sun and planets follow), Spica is often blocked by the Moon. This provides astronomers with unique opportunities to measure its properties. It is a B-type main-sequence star, meaning it is incredibly luminous and rich in helium.

Of the rocks, spinel is a hard magnesium-aluminum oxide often found in stunning red or blue crystals. Sphalerite is the chief ore of zinc, known for its resinous luster. Schist is a metamorphic rock characterized by the way its large, platy mineral grains align in wavy layers that catch the light with a distinctively metallic sheen. Finally, skarn is a coarse-grained metamorphic rock formed when magma interacts with carbonate rocks like limestone, often resulting in colourful rock.

Answer: Tarazed

Located in the constellation of the Eagle, Aquila, right next to the much more famous Altair, Tarazed is a bright orange bright giant star located approximately 395 light-years away from us. It is one of the "shoulders" of the bird. While Altair is relatively young and close to Earth, Tarazed is a massive, evolved star that has consumed the hydrogen in its core and expanded to about 95 times the diameter of our Sun. If you placed it in our solar system, its outer edges would reach nearly halfway to the orbit of Venus.

Despite being a giant of a star, Tarazed is only about 100 million years old. This makes it a mere fraction of our Sun's age. its high mass caused it to live its life at a breakneck pace which means that our Sun will outlive it. It is currently fusing helium into carbon in its core, a process that generates a staggering amount of energy. Thus, it shines over 2500 times brighter than the Sun.

Tungsten is a dense, silvery-white metal with the highest melting point of all elements. Turquoise is a hydrated phosphate of copper and aluminum prized for its unique blue-green hue. Finally, topaz is a hard silicate mineral that occurs in a wide range of colors, from golden yellow to deep blue.

Answer: Diphda

Diphda, which is also known by its traditional name Deneb Kaitos, is the brightest star in the constellation Cetus, the Whale. Despite its "Beta" designation, it actually outshines the "Alpha" star of its constellation. Diphda is an orange giant located rather close, about 96 light-years away from Earth. It has evolved past the stable main-sequence phase of its life and has expanded to about 17 times the radius of our Sun.

While it appears as a steady point of light to the naked eye, X-ray observations have revealed that Diphda has a surprisingly active corona, emitting about 2,000 times more X-ray energy (outside the visible spectrum) than our Sun. This high level of activity is rather unusual for a star of its age and type. It may suggest that Diphda has powerful magnetic fields generated by its own internal rotation. Astronomers classify it as a "clump" giant, meaning it is currently burning helium into carbon in its core.

And as for the rocks, diabase is a dark, intrusive igneous rock often found in sills and dikes, while d'ansite is an incredibly rare sulfate mineral usually found in evaporite deposits. Dolomite is a common sedimentary carbonate mineral that forms entire mountain ranges, like the Dolomites in Italy, where it gets its name.

Answer: Mizar

Mizar is one of the most famous stars in the night sky. It is located at the "curve" in the handle of the Big Dipper (Ursa Major). Historically, it is significant as the first binary star ever discovered by telescope, and also the first to be photographed. To the naked eye, Mizar sits right next to a dimmer companion called Alcor. For centuries, being able to distinguish the two was used as a test of eyesight. However, modern astronomy has revealed that Mizar is far more complex than you can see - it is actually a quadruple star system consisting of two pairs of binary stars!

The stars in the Mizar system are hot, white, A-type stars, and are located 83 light years away. These stars are all significantly more massive and luminous than our Sun. Due to the four stars being in close proximity, there are likely interesting gravitational events occurring in the star system.

Magnetite is a natural black iron oxide and is the most magnetic of all minerals. Mica is famous for its perfect cleavage, allowing it to be peeled into thin, flexible, transparent sheets. Marble is a metamorphic rock that began as limestone and is prized for its beauty in sculpture.

Answer: Larawag

Larawag is a bright orange giant star located approximately 63 light-years away in the constellation Scorpii. While it was long known by the traditional name Wei, it was officially renamed Larawag by the International Astronomical Union in 2017 to honor the traditions of the Wardaman people of Northern Australia. In Wardaman culture, Larawag is the 'signal receiver', a celestial watchman.

While Larawag is only 1.41 times the mass of our Sun, it is a star that has exhausted the hydrogen in its core and expanded to about 13 times the diameter, cooling as it grew to its current orange hue. It is also 70 times more luminous than the Sun, and is a good way of seeing what will happen to our central star in a couple of billion years.

The rocks in this question are all colourful examples of minerals found in the earth. Lepidolite is a lilac-gray, lithium-rich mineral of the mica group. Larimar is a rare blue variety of pectolite found only in the Dominican Republic, while lapis (often called lapis lazuli) is a deep-blue metamorphic rock containing lazurite and pyrite.