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Cosmic Challenge: NGC 7354


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Cosmic Challenge:
NGC 7354

 

November 2023  

 

Phil Harrington

 

 

This month's suggested aperture range:

6 to 9.25 inch
(15-24cm) telescopes

 

 

 Target

 Type

 Constellation

 RA

 Dec

 Magnitude

 Size  

 NGC 7354

 Planetary nebula 

 Cepheus

 22h 40.3m 

 +61° 17.1 

 10.2

 36"

 

Of the constellations that line the autumn Milky Way, King Cepheus, the king of Aethiopia in Greek mythology, is trod upon by relatively few amateur astronomers.  While this is most likely because the constellation's brightest stars are faint compared to his wife, Queen Cassiopeia, the King has many royal deep-sky subjects is his own right that merit a look, including this month's challenge.

 

Discovered by William Herschel in 1787 and lying some 5,538 light years from the solar system, NGC 7354 is a splendid little planetary nebula, even if it does not receive much attention.  It lies among the faint stars of southeastern Cepheus, not far from the Cassiopeia border.

 

 

Above: Evening star map showing the location of this month's Cosmic Challenge.

Credit: Map adapted from Star Watch by Phil Harrington

 

 

To find it, place the famous variable star, Delta (δ) Cephei near the southern edge of your finder's field.  There, a 5th-magnitude star, 30 Cephei, should just pop into view along the field's northern edge.  Center your aim about two-thirds of the way from Delta to 30, and then shift about half a degree east.  NGC 7354 should be in your telescope's field, nestled between a pair of 11th-magnitude stars to its northwest and a lone 11th-magnitude sun to its southeast.

 


Above: Finder chart for this month's Cosmic Challenge

Credit: Chart adapted from Cosmic Challenge: The Ultimate Observing List for Amateurs by Phil Harrington.
Click on the chart to open a printable PDF version.

 

From my suburban backyard, my filterless 6-inch Schmidt-Cassegrain telescope shows NGC 7354 as a round, grayish disk at 127x.  The disk appears perfectly uniform and, with an apparent diameter of half an arcminute, is clearly identifiable as nonstellar.  Try the highest magnification that sky conditions and your telescope can bear for the best view.  Its central star may only shine at 16th magnitude, but it has a temperature close to 100,000 Kelvin (179,540°F, 99,727°C).

 

Above: Rendering of NGC 7354 through the author's 6-inch (15.2 cm) f/10 Schmidt-Cassegrain at 127x.

 

Photographs of NGC 7354 reveal a complex multi-shell structure, with a brighter, ellipsoidal inner shell encircled by a spheroidal, fainter outer shell.  Flame-like FLIERs are also evident in some images.  FLIERs, an acronym for "Fast, Low Ionization Emission Regions," are red in color and appear to shoot outward from planetary nebulae.  Their exact cause and creation remain a mystery, but some suggest that FLIERs result from subsequent bursts of matter flung outward from the central star after the planetary itself formed.  Given their high rates of speed, it seems certain that whatever their cause, FLIERs are created independently from, and are formed after, the more slowly expanding planetary nebula. Research suggests that these features could also be due to a companion central star. The presence of a second star in NGC 7354, however, is yet to be confirmed.

 

Above: Image of NGC 7354 taken by CN'er Steveincolo

Details: AT130EDT at 728 mm; AT 0.8x FF/FR; ZWO LRGBSHO filters in ZWO EFW; ASI533MM at 5C, gain 100. Stacked in Jocular.

 

Below: NGC 7354 captured by the Hubble Space Telescope. Credit: Judy Schmidt via Wikimedia Commons

 

Good luck with this month's challenge! Be sure to post your results in this column's discussion forum. And remember that half of the fun is the thrill of the chase.  Game on!



About the Author:

Phil Harrington writes the monthly Binocular Universe column in Astronomy magazine and is the author of 9 books on astronomy, including Cosmic Challenge: The Ultimate Observing List for Amateurs.  Visit www.philharrington.net to learn more.

Phil Harrington's Cosmic Challenge is copyright 2023 by Philip S. Harrington.  All rights reserved.  No reproduction, in whole or in part, beyond single copies for use by an individual, is permitted without written permission of the copyright holder.

 


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