Look Up! Facts About Stargazing

1

Just how many stars can we see with the naked eye? The Yale Bright Star Catalog provides the answer: 9,095. Except we can’t see all of them at once because at least half would fall below the horizon. Daylight and haze also limit us. So in fact, the number of stars we can see at night at any given time is around 2,000.

2

The largest star visible with the naked eye is Mu Cephei, a strikingly red star in the constellation Cepheus (the King). If our sun was the size of a softball, Mu, in comparison, would be 437 feet across. The brightest star in the sky is Sirius, or the Dog Star, in the constellation Canis Major. Orbiting it is a white dwarf star known as Pup. Though about the size of Earth, Pup is far denser. On our planet, a teaspoon of its material would weigh 5 tons.

3

The farthest celestial object visible without a telescope is the Andromeda galaxy, 24 quintillion kms away. On a clear night, it appears as a faint elongated patch. When its light began travelling earthward, mastodons and saber-toothed tigers roamed North America. An estimated 1 trillion stars make up Andromeda, more than twice the number in our own Milky Way galaxy.

4

Contrary to popular belief, Galileo did not invent the telescope. The genius behind it was spectacle-maker Hans Lippershey, who applied for the patent in 1608. Telescopes were initially pointed not at the sky, but at the seas—to spy on ships. Galileo first turned a telescope toward the heavens in 1609.

5

The idea of constellations goes back tens of thousands of years, as people have always seen outlines of people and animals in the night sky and made up stories about them. But in the 17th century, Johannes Hevelius introduced seven that are still among the 88 we recognize in the sky today, including Lacerta (the Lizard) and Vulpecula (the Fox). Hevelius had no love for telescopes, however. His star atlas Firmamentum, published in 1690, features a cartoon of a cherub holding a card with ‘The naked eye is best’ written in Latin.

6

The light that emits from the star Spica in the constellation Virgo takes 250 years to reach Earth and become visible to us. Put in other terms, this means that in 2026 the light we see coming from Spica would have begun its earthward journey around the time British colonial rule began de jure in India.

7

Camera lenses have improved a lot since the first photograph of a star was taken at Harvard College Observatory in 1850. To shoot stars with your phone’s camera, use the night mode (available on newer Androids and iPhones), which lets you record exposures of several seconds or more. A tripod and a Bluetooth shutter trigger further improve your results.

8

Lots of locales across India have dark, starry skies ideal for stargazing. Spiti Valley in Himachal Pradesh, Sonmarg in Jammu and Kashmir, and Pangong Tso lake in Ladakh has some of the nation’s starriest skies. Coorg in Karnataka, Gujarat’s Rann of Kutch, Jaisalmer and Churu in Rajasthan and Shnongpdeng in Meghalaya are also some locations highly regarded as an oasis for starry skies, among many others.

9

Astronomy is the oldest of the sciences, making it the oldest scientific hobby. As a teenager in Ohio in the early 1900s, Leslie Peltier became fascinated with stars. Today, he is fondly remembered as the world’s greatest amateur astronomer. He died in 1980, having discovered a dozen comets and submitted more than 1,00,000 observations of stars to the American Association of Variable Star Observers during his lifetime.

10

Another American astronomer, Garrett Serviss, once wrote, “Stargazing is a great medicine of the soul.” But there’s a big problem affecting stargazers across the world: light pollution, caused by excessive or misdirected outdoor lighting. The spread of light pollution over the past half-century is a major reason why approximately 90 per cent of Americans have never seen the Milky Way, and 80 per cent struggle to see stars near their homes.

11

To help reduce extra nighttime lighting in your own neighborhood, consider joining Dark Sky International. The ­organization aims to ­protect communities—of people and wildlife—from unnatural and irresponsible outdoor lighting. Its website (darksky.org) provides information about local laws regarding what is known as “light trespass.” For example, if you have a neighbor whose bright lights shine onto your property, you can take legal steps to have those lights shut off or properly shielded.

12

We all know birds fly south for the winter. But how do they find their way? A 1967 study conducted at Cornell University under the artificial skies of a planetarium suggests that the indigo bunting, a songbird common throughout the eastern United States and Canada, obtains directional information from star patterns such as the Big Dipper to guide its annual migration.

13

Seeing a comet is a rare treat, but there’s a chance one may come our way this month. The comet, called Tsuchinshan-ATLAS, will pass 57 million kms from the sun in late September; two weeks later, it will come within 70 million km of Earth. Comets are notorious-ly unpredictable, but this one might be bright enough to see, so look low in the sky one to three hours after sunset during the third week of October.

—with Inputs by ishani nandi