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Spiral Galaxy (NGC 7606) & Spiral Galaxy(NGC 7479)
Katie Funk & Stephanie Haggis

NGC7606 Herschel H55-1
NGC 7606 - Katie Funk NGC 7479 - Stephanie Haggis

A galaxy is "a great island of stars in space, containing millions, billions, or even trillions of stars, all held together by gravity and orbiting a common center" (Bennet, et. al, pg. G-5). A spiral galaxy looks "like flat white disks with yellowish bulges at their centers. The disks are filled with cool gas and dust, interspersed with hotter ionized gas, and usually display beautiful spiral arms" (Bennet, et. al, pg. G-13). Spiral galaxies can be either barred or unbarred. The arms of an unbarred spiral project directly from the bulge, while the arms of a barred gallaxy protrude from an apparent "bar" that runs through the middle of the bulge.

NGC 7606 is a spiral galaxy found in the Aquarius constellation (NGC 7606). It is located at a distance of about 97 million light years away (Harrison). According to the Hubble classifications, it is an Sb type galaxy. "S" refers to it's spiral shape, while "b" tells us that its arms are not too loose or too tight (Hubble Classification). Its arms protrude directly from the bulge, meaning it is a non-barred spiral galaxy. It was discovered in 1785 by William Herschel (Harrison). Its yellow color tells us that it has an older population and is probably not forming many new stars anymore, especially nearer the central bulge.

Spiral Galaxy NGC 7479 is an interesting Galaxy. The arms of the galaxy point one way, but according to the radio wave technology, the radio waves point the other direction and spins the other way. It is even “sometimes nicknamed the Propeller Galaxy, spins the other way, with a jet of radiation that bends in the opposite direction to the stars and dust in the arms of the galaxy”. (Spiral Spins Both Ways). Like most Spiral Galaxies, NGC 7479 has lots of star activity due to the abundance of gas at the right temperature. According to Wikipedia, NGC 7479 was discovered by William Herschel in 1784. Another interesting fact is that “polarization studies of this galaxy indicate that it recently underwent a minor merger and that it is unique in the radio continuum, with arms opening in a direction opposite to the optical arms” (Laine, 2005). NGC 7479 lies in the Pegasus constellation. It has an apparent magnitude of 11.5 and is about 105 million light years away (Wikipedia).

Other than being spiral galaxies, NGC 7606 and NGC 7479 only have a few things in common. They were both discovered by William Herschel with NGC 7479 being discovered one year before NGC 7606. Both galaxies are about 100 million light years away from earth, and both are 11.5 magnititude galaxies (NGC 7606, Wikipedia). This, combined with the similar distances, tells us that NGC 7606 and NGC 7479 have similar luminosities.

There are a few differences between NGC 7606 and NGC 7479. The most obvious difference is the structure. The arms of NGC 7606 or much more tightly wound; it has a Hubble classification of Sb.The arms of NGC 7479 are much more open; it has a classification of SBc. NGC 7479 is also a barred galaxy, whereas NGC 7606 is not. NGC 7606 also does not have any unique features such as NGC 7479's jet of radiation that moves in the opposite direction of the arms.

References:

Bennett, Jeffrey O., Megan Donahue, Nicholas Schneider, and Mark Voit.The Cosmic Perspective Fundamentals. Second ed. San Francisco, CA: Pearson Addison-Wesley, 2010. Print.

Harrison, Tom. "NGC 7606." NGC 7606 (Tom Harrison) | AstroBin. AstroBin, 2015. Web. 10 Dec. 2015.

"Hubble Classification." COSMOS. Swinburne University of Technology, n.d. Web. 10 Dec. 2015.

"NGC 7606." Observing at Skyhound. N.p., n.d. Web. 10 Dec. 2015.

"Spiral spins both ways." Hubble Space Telescope. ESA, n.d. Web. 3 Dec. 2015 < https://www.spacetelescope.org/images/potw1125a/ >

Wikipedia. N.p., 29 July 2015. Web. 3 Dec. 2015. <https://en.wikipedia.org/wiki/NGC_7479>.

 

 

 

Object NGC 7606 NGC 7479
Right Ascension (J2000) 23:19:04 23:04:56
Declination (J2000) -08:29:11 12:19:20
Filters used B (Blue), C (Clear), R (Red), V (Green) B (Blue), R (Red), V (Green)
Exposure time per filter B, V, and R (300s); C (60s x 5) B (300 x 2), V, and R (150s)
Image dimension 280X280 pixels; 6X6 arcminutes 256X149 pixels; 5.5X3.2 arcminutes
Date/time observed October 1, 2015, 4:53 UT

October 1, 2015, 9:50 UT (B, R)

October 14, 2015, 1:40 UT (V)

 

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