50 Things To See With A Small Telescope Page 3

  19. Saturn

  One look at Saturn and you might trade in your car for a telescope of equal value. Or not. Either way, it’s quite a sight.

  Saturn’s glorious rings set this planet apart from the others. In a small telescope on a clear evening, you may be able to see the gaps between the two main rings. This gap is called the Cassini Division.

  The most detailed image of Saturn came from NASA's Cassini spacecraft.1 As I’m writing this, the plutonium powered spacecraft only has a few months left before NASA will pilot it into Saturn’s atmosphere, ending the probe’s twenty-year mission. One of the Cassini probe’s most exciting finds occurred while investigating Saturn’s moon Enceladus, where it photographed over one hundred erupting geysers. The geysers spew water and molecular hydrogen from a subsurface ocean. We’ll have to wait until a future mission to investigate this occurrence in more detail, but this discovery adds yet another world where scientists may search for life.

  As with any planet, check your stargazing software to make sure Saturn is visible during your observing session.

  1https://saturn.jpl.nasa.gov/galleries/images/

  20. Titan

  Titan is the largest moon of Saturn. What better place to drop out of warp to avoid detection from a Romulan mining vessel, like in the blockbuster movie Star Trek 11.

  What is most interesting about Titan is that the gravity is low enough, and the atmosphere thick enough, that by attaching small wings to your arms, you could fly like a bird!

  On January 14th, 2005, NASA landed a small probe named Huygens on Titan. Huygens penetrated Titan’s thick atmosphere and parachuted to the ground. The probe took photos all the way down, and one photo from the surface (shown to the right).

  Because Titan has a thick atmosphere, it also has an interesting climate. The surface temperature is almost -180 °C, and it often rains liquid methane. In addition to rain, radar images of the planet’s surface confirm the existence of hydrocarbon seas and lakes.

  To find Titan, first, find Saturn. Once you have found Saturn, Titan will be found orbiting beside it. On clear nights, or with a mid-sized telescope, three additional moons, Rhea, Tethys, and Dione, may also be visible.

  21. Uranus

  The planet Uranus was discovered by the astronomer William Hershel, in 1781. Hershel originally believed he had discovered a comet or star, and it was two years before it officially became known as a planet.1

  To English speakers, the most interesting thing about Uranus is its name, which shares the pronunciation with a certain private part of human anatomy. Though it sounds funny to some people, its name is very logical. Saturn is the father of Jupiter, and Uranus is the father of Saturn. It’s one big family out there in the outer solar system.

  Uranus and Neptune are known as the “ice giants” of our solar system. This is due to their vast distance from the Sun, and their status as gas giants (planets composed primarily of gas, that are much larger than Earth). Uranus orbits at twice the distance of Saturn, and almost twenty times the distance between the Earth and the Sun (a distance called one astronomical unit).

  For the first few decades in the twenty-first century, the best time to view Uranus is in September and October. In larger telescopes, you may be able to see several of Uranus’ moons.

  To find Uranus, first check your astronomy software to find the precise location. Use a low magnification eyepiece, or binoculars, to make the initial find, and then move to a higher magnification eyepiece to resolve the planet and more of the its hue. Don’t expect to see too see much detail; at best Uranus will appear as a hazy blue star.

  1NASA: Uranus: in Depth https://solarsystem.nasa.gov/planets/uranus/indepth

  22. Neptune

  Now that Pluto has been demoted to a “dwarf planet” by the Astronomical Union, Neptune is the farthest planet from the Sun (in our solar system). Like the other planets (besides Earth), this one is named after a Roman god, the god of the Sea.

  This planet is very far from the Sun, about fifty percent farther than Uranus. It took the Voyager spacecraft twelve years to reach Neptune, and it was the last planet visited in the Voyager program’s grand tour of the Solar System.1

  Neptune’s largest moon, Triton, is visible in telescopes like my twelve inch Dobsonian (a water-heater sized telescope currently sitting in our living room). However, this moon is most likely too dim for smaller telescopes.

  Neptune, itself, is very dim, one of the dimmest objects in this book. Only telescopes six inches in diameter, or larger, will be able to resolve Neptune into a disk. For smaller telescopes, the planet will appear as a blueish point of light. However, its blue color distinguishes it from background stars. As with Uranus, use an eyepiece without much magnification to find the planet. Then, use an eyepiece with high magnification to get a better view.

  1NASA: Neptune: in Depth https://solarsystem.nasa.gov/planets/naptune/indepth

  Part Three

  Deep-Sky Objects

  Deep-sky objects are where seasoned amateur astronomers spend most of their observing time. Most folks start with the “Messier Catalogue”: a list of 110 objects recorded by Charles Messier in the 1770’s. Messier was a comet hunter, and his list was composed of “frustrating (to him)” objects that were not comets (examples include: M1, the Crab Nebula, and M42, the Orion Nebula). Little did he know that his list would be immortalized as a compilation of some of the most interesting objects in the sky.

  Seasoned astronomers, with larger telescopes, often pursue targets from other lists, such as the Caldwell Catalogue: a 109-item extension to the Messier Catalogue, that basically summarizes the next best 110 targets. Examples from the list include C-14, the Double-Cluster, and C-4, the Iris Nebula (we’ll explore the Iris Nebula in 50 Targets for the Mid-Sized Telescope).

  The most comprehensive list of deep-sky objects is called the New General Catalogue (NGC). This list contains 7,840 items. This list overlaps with both Messier’s list and the Caldwell Catalogue.

  23. The Milky Way

  If you’re an amateur astronomer (if you own a telescope, that’s you) and you can’t find the Milky Way, you need to find darker skies! In fact, all of the stars that you see in the night sky are part of the Milky Way. When we say we see the Milky Way, we’re are actually referring to the plane of the Milky Way. You can clearly see the plane in the photo, below.

  If you live near a large town or city, you probably cannot see the white wispiness that makes up the plane of the Milky Way. In fact, the maximum number of visible stars in the sky from within a large city is only about a dozen. Far from city lights, you might count as many as 6000 stars on a moonless night. The Milky Way contains between 300 billion and 400 billion stars! That is why it appears as a white wispiness in truly dark skies.

  One of the ways to explore the plane of the Milky Way with a telescope is to start at one horizon and work your way across to the other. With patience, you’ll find many star clusters beyond what’s mentioned in this book.

  24. The Orion Nebula (M42)

  The Orion Nebula is often dubbed the “Star Factory”. When you observe this nebula, you can see a great expanse of gas surrounding a series of stars. It is called the “Star Factory” because these stars are being formed out of that gas.

  The Orion Nebula is part of the Orion Molecular Cloud Complex, which also contains the Horsehead Nebula. Although the Horsehead is far too dim to see in a small telescope, it is nonetheless the location of “The Planet of the Ood” from BBC’s classic series Doctor Who.

  The Orion Nebula is one of the easiest to find deep-sky objects (objects not located in our Solar System). To locate the nebula, find Orion’s belt, and then imagine his sword as the line of stars running down from the belt. The middle of this sword contains the Orion Nebula.

  25. The Hyades

  The Hyades, residing in the center of the constellation Taurus, is the nearest open star cl
uster, and thus makes for a great target for binoculars or small telescopes. It is best viewed during the winter months, as it precedes Orion in its path through the sky. Visually, the cluster is accented by the red giant star Aldebaran. However, this is simply a chance coincidence. Aldebaran is not actually a part of the cluster at all, as it lies much closer to Earth.

  The cluster features a bright naked-eye double star, Theta Tauri, or θ Tau for short. The individual stars are designated θ¹ Tauri and θ² Tauri. On close inspection with a telescope, you should be able to make out a color difference between the two stars of almost equal brightness (one appears slightly orange, and the other white).

  26. The Pleiades (M45)

  You can skip this one if you drive a Subaru, because you see this star cluster every time you look at your steering wheel. If you don’t drive a Subaru, then the Pleiades can be found to the right of Orion (that’s your right, Orion’s left). According to Greek mythology, the Pleiades, or Seven Sisters, were turned into stars by Zeus to help them flee Orion, who, ironically, still pursues them through the night sky.

  Some people think that this cluster of stars is the Little Dipper. It’s not. The actual Little Dipper is quite dim, yet considerably larger than the Pleiades, and is located in the northern sky.

  To find the Pleiades, look up and to the right of Orion. Usually, with any amount of light pollution, only 6 of the brightest stars in the Pleiades are visible to the unaided eye. However, as soon as you look in your telescope, dozens of stars will appear!

  27. The Hercules Star Cluster (M13)

  This globular cluster is one of only a few objects in this book that resides outside the plane of the Galaxy! It is also where the Earth was hidden in Dan Simmon’s classic (1989) novel Hyperion (sorry for the spoiler).

  M13, occassionally called the “Great Globular Cluster in Hercules” is one of the brightest deep sky objects. It’s also relatively easy to find, because it’s one of the largest globular clusters, containing several hundred thousand stars. If you are using binoculars or a very small telescope, M13 will appear as a grey glob (hence globular).

  To find M13, search the side of the Keystone (an asterism in Hercules); pan around the edge of the square until you find it.

  28. The Andromeda Galaxy (M31)

  Before the twentieth century, the Milky Way was thought to be the only galaxy in the universe. Astronomers dubbed objects that seemed to reside outside of the galaxy “Island Universes”. It wasn’t until Edwin Hubble measured the distance to the Andromeda Galaxy that debate over the Island Universes closed. Before Hubble, many astronomers believed that the Andromeda Galaxy was actually a nebula, and called it The Andromeda Nebula.

  The cool thing about the Andromeda Galaxy is that it is over six times as wide as the full Moon! However, the only way to see the full extent of this galaxy is through long exposure photography. When you see the Andromeda Galaxy in your telescope, you only see the bright galactic core, which appears as a beautiful grey smudge.

  To find the Andromeda Galaxy, use the constellation Cassiopeia. Observe the distance between any two stars in the W, then count three of these lengths in the direction (away from the North Star) shown below.

  29. The Dumbbell Nebula (M27)

  Discovered in the year 1764 by the French astronomer Charles Messier, the Dumbbell Nebula was the first planetary nebula ever discovered. It also has a very large apparent size in a telescope. The photo below shows its apparent size, relative to the Moon.

  M27 is located in the Summer Triangle, between the constellations Vulpecula and Sagitta. Interestingly, the Dumbbell Nebula wasn’t given its name until 1833, when astronomer John Herschel made this record: “A nebula shaped like a dumb-bell, with the elliptic outline completed by a feeble nebulous light.”

  30. Albireo

  Albireo is probably my favorite double-star to show off at stargazing events. This is due to the striking color contrast between the two stars. The brighter of the two stars, Albireo A (Beta Cygni A), appears yellow or amber, while Albireo B (Beta Cygni B) is blue. Although this star spends most of the winter below the horizon, there is an almost identical double star, dubbed “Winter Alberio”, in Canis Major. However, Winter Alberio (145 Cma) is slightly more challenging to find, so we’ll save that for 50 Targets for the Mid-Sized Telescope.

  This double star is found at the base of the Northern Cross, and within the Summer Triangle. If you have a cell phone adapter for your telescope, this is a great star to photograph, as the phone’s camera will accentuate the contrasting colors between the two stars.

  31. Mizar & Alcor

  No need for optometrists when you have these two stars in sight. Nicknamed the “Horse and Rider”, seeing these stars, located in the Big Dipper, used to be a test of eyesight! These days, most people can make out these two stars with corrected lenses. Mizar and Alcor make up the center of the handle of the Big Dipper.

  In addition to being a visual double star, Mizar was the first telescopic double star ever observed. It was discovered by an Italian mathematician named Benedetto Castelli, in 1617.

  When observing these stars, first notice the double stars which can be seen with the unaided eye, then look at the stars through the telescope. Mizar will be the star with the companion so close they appear to almost touch.

  32. Double Cluster in Perseus

  These star clusters are notable for two reasons. First, they are easy to find from the Northern Hemisphere, since they are above the horizon most evenings of the year. Second, each year the Perseid meteor shower originates from this part of the sky, in mid-August.

  These two clusters, designated NGC 869 and NGC 884 (or Caldwell 14, together), are visible to the naked eye in extremely dark skies (a rarity in today’s modern world). NGC stands for “New General Catalog”, a list of almost eight thousand nebulae and star clusters compiled in the late 1800’s. “Caldwell” is a catalog of 109 targets best suited for amateur astronomers.

  Star clusters are great for showing just how many stars are out there! To find the double Cluster in Perseus, look to Cassiopeia (the big W) and find the clusters below and to the left of the W (or up and to the right of a big M, depending on the time and season, or time of night).

  33. The Ring Nebula (M57)

  The Ring Nebula appears about as large as Jupiter in your telescope, but not nearly as bright. The challenge, in a small telescope, is to clearly make out the hole in the Ring. In order to view the center of the Ring, you may need a telescope with a lens or mirror of at least 10cm in diameter, but the disk shape is visible in smaller telescopes. Make sure your eyes are adapted to the dark for optimal viewing, and practice “averted vision” (observing something without looking directly at it) to take advantage of the more sensitive light-detecting cells in your eye’s retina.

  This Nebula was formed when a red giant star shed its outer shell of ionized gas, leaving only a white dwarf star where the red giant once was.

  To find the Ring Nebula, pan the telescope between the two stars opposite Vega in the Diamond pattern in the constellation Lyra.

  34. The Whirlpool Galaxy (M51)

  The Whirlpool Galaxy, or M51, is easy to find in a small telescope, or even binoculars, but only on moonless nights and far from city lights. This Galaxy is accompanied by a smaller companion galaxy designated NCG 5191, or M51b. The gravitational interaction between these two structures is thought to give the Whirlpool its well defined spiral shape.

  Astronomers have discovered that most large galaxies have a supermassive black hole at their center, and observations of M51 by the Hubble telescope reveal a distinct X shaped pattern around this galaxy’s center. One bar of the X is most likely dust circling the black hole. The second bar of the X could be dust interacting with a cone of ionized particles. Further observation is required before astronomers reach a scientific consensus.

  Supernovae have also been observed in this galaxy in 1994
, 2005, and 2011.

  To find the Whirlpool Galaxy, make a right triangle under the handle of the Big Dipper, as shown below.

  35. The Trifid Nebula (M20)

  In the first section of this book, we introduced the Teapot in Sagittarius as a great place to explore deep-sky objects (deep-sky means objects outside of our Solar System). Even without using a star map, you’re bound to run into several interesting targets. The Teapot is regarded as one of the best places to scan the sky, using binoculars.