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Phil Harrington's Cosmic Challenge
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If you're like me, you have probably seen Jupiter, Saturn, the Orion Nebula, and all of the sky's showpiece objects more times than you can count. And while they are truly spectacular and well worth revisiting, you may be looking for something new, something challenging to observe.
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Cosmic Challenge: Apollo Landing Sites
May 31 2019 11:46 AM |
PhilH
in Phil Harrington's Cosmic Challenge
Between July 1969 and December 1972, six teams of United States astronauts ventured across the gap between Earth and Moon to land and walk on that distant world. Have you ever visited their landing sites? If not, let's do so now.
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Cosmic Challenge: M51's spiral arms
Apr 30 2019 07:52 AM |
PhilH
in Phil Harrington's Cosmic Challenge
Of the thousands of spiral galaxies visible through backyard telescopes, one stands above the rest in terms of visual interest: M51, the famous Whirlpool Galaxy in Canes Venatici. Everything adds up in M51's favor. We are seeing it very nearly face-on, its spiral arm halo is bright and peppered with star clouds and vast regions of nebulosity, and it brings with it a friend in the form of a smaller companion galaxy that can even be seen through giant binoculars.
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Cosmic Challenge: Leo III
Mar 30 2019 09:54 AM |
PhilH
in Phil Harrington's Cosmic Challenge
A springtime rite of passage started here two years ago. It started in the April 2017 edition of this e-column, when I challenged readers to find the dwarf galaxy Leo I. Leo I is one of many dim dwarf galaxies gravitationally bound to the Milky Way. The fact that its surface brightness rates only 15th magnitude, coupled with its position just 20' north of Regulus makes Leo I a tough challenge to land.
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Cosmic Challenge: NGC 2363 and NGC 2366
Feb 28 2019 04:59 PM |
PhilH
in Phil Harrington's Cosmic Challenge
Will the real NGC 2363 please stand up? For years, there has been an ongoing debate over the true identity of the 2,363rd entry in the New General Catalog.
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Cosmic Challenge: Sharpless 2-301
Feb 01 2019 02:39 PM |
PhilH
in Phil Harrington's Cosmic Challenge
While a few of Sharpless's entries, such as Sh2-25 (better known as M8, the Lagoon Nebula) and Sh2-49 (M16, the Eagle Nebula), are well known to visual observers, most are among of the most challenging objects to see visually. If you have never made a concerted effort to see some of the lesser known Sharpless objects, then this challenge, Sh2-301 in Canis Major, is a good introduction to the sport.
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Cosmic Challenge: Jonckheere 320
Jan 01 2019 06:04 AM |
PhilH
in Phil Harrington's Cosmic Challenge
On January 22, 1916, while revisiting some of the stars in his Catalog and Measures of Double Stars discovered visually from 1905 to 1916 within 105° of the North Pole and under 5" Separation, French astronomer Robert Jonckheere returned to a vague double in Orion, which he had previously designated as entry number 320. Jonckheere was later to write of this encounter through the 28-inch refractor at the Royal Greenwich Observatory, "I noticed that the object I have catalogued as J 320 is not a double star, but, like J 475, it appears with the larger instrument to be an extremely small bright elongated nebula. As is the case with J 900, this object also appears to be new as a nebula."
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Cosmic Challenge: Globular clusters in M31
Dec 01 2018 06:00 AM |
PhilH
in Phil Harrington's Cosmic Challenge
The Andromeda Galaxy, M31, was probably one of the first galaxies you ever saw first-hand. It was mine. That was all way back in 1969. Since then, I have grown to appreciate it as far more than just the ill-defined oval blur I drew in my logbook. But in 1969, the thought of looking for individual objects within M31 never crossed my mind.
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Cosmic Challenge: NGC 147 and NGC 185
Nov 04 2018 08:46 AM |
PhilH
in Phil Harrington's Cosmic Challenge
M32 and M110 are nice challenges for handheld binoculars. Most amateurs are familiar with them, since they lie in the same field of view of the parent Andromeda Galaxy. But two others, designated as NGC 147 and NGC 185, are not as nearly well known. Both are several degrees to M31's north, across the border in Cassiopeia and feature smaller, fainter disks that are much more challenging to see.
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Cosmic Challenge: Einstein's Cross
Oct 01 2018 08:53 PM |
PhilH
in Phil Harrington's Cosmic Challenge
From an aesthetic perspective, the most perfect gravitational lens is Einstein's Cross, formed by the galaxy PGC 69457 (cross- cataloged as CGCG 378-15) and the quasar QSO 2237+0305 in Pegasus. PGC 69457 is also known informally as Huchra's Lens after its discoverer, John Huchra, professor of cosmology Harvard University. Current estimates place this small, otherwise unspectacular spiral galaxy at 400 million light years away. The quasar lurks far behind at an incredible distance of 8 billion light-years. Were it not for gravitational lensing, the quasar would remain hidden by the galaxy, as the two are nearly in-line as seen from Earth. But as it is, Huchra's lens fractures the ancient light from the quasar into four separate paths that slide around the galaxy just as water flows around a rock in a stream. The end result is not one, but four ghostly images of QSO 2237+0305 surrounding the nucleus of PGC 69457 in a practically perfect diamond pattern.
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Cosmic Challenge: North America Nebula (NGC 7000)
Sep 01 2018 05:07 PM |
PhilH
in Phil Harrington's Cosmic Challenge
The North America Nebula (NGC 7000) is a large expanse of glowing hydrogen gas mixed with opaque clouds of cosmic dust just 3° east of Deneb [Alpha (α) Cygni] and 1° to the west of 4th-magnitude Xi (ξ) Cygni. Famous as one of the most luminous blue supergiants visible in the night sky, Deneb marks the tail of Cygnus the Swan, or if you prefer, the top of the Northern Cross asterism.
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