OBSERVER’S CHALLENGE* –OCTOBER, 2019
by Glenn Chaple
NGC 7448 – Spiral Galaxy in Pegasus (Mag: 11.4 Size: 2.7’ X 1.2’)
As promised last month, we leave the relatively easy Messier stuff behind and return to the realm of the faint fuzzies – in this case the spiral galaxy NGC 7448 in Pegasus. When William Herschel discovered it on October 16, 1784, he assigned it the Herschel Catalog designation H2512 – his 251st Class II entry. The Class II category was reserved by Herschel for what he considered to be “Faint Nebulae”. As such, it is a visual challenge for owners of modest-sized telescopes.
Viewed with my 10-inch f/5 reflector under magnitude 5 skies, NGC 7448 was a ghostly presence – a rather faint averted vision sight. I sensed an oval shape with a NW/SE orientation – an impression verified by descriptive notes in Volume 1 of Kepple and Sanner’s Night Sky Observer’s Guide and images sent by Doug Paul and Mario Motta.
Motta’s image shows bright detached segments surrounding the inner disk. Because of these, Halton Arp included NGC 7448 in his Atlas of Peculiar Galaxies with the designation Arp 13.
The 2000.0 coordinates for NGC 7448 are 23h00m, +15°59’. Star-hoppers can work with the finder charts below, which show its location 1 ½ degrees WNW of Markab (alpha [α] Pegasi). NGC 7448 is approximately 80 million light years from Earth and is about 60,000 light years in diameter.
*The purpose of the Observer’s Challenge is to encourage the pursuit of visual observing and is open to everyone who is interested. Contributed notes, drawings, or photographs will be published in a monthly summary. Submit them to Roger Ivester (rogerivester@me.com). To access past reports, log on to rogerivester.com/category/observers-challenge-reports-complete.
Finder charts for NGC 7448
www.constellation-guide.com (from IAU and Sky & Telescope)
Chart created using AAVSO’s Variable Star Plotter (VSP). North is up on a 2-degree field; limiting magnitude 11. Numbers indicate magnitudes of field stars (decimals omitted). Bright star at lower left is Markab (alpha [α] Pegasi). The location of NGC 7448 is shown with a “+”.
NGC 7448 (Image by Mario Motta, MD)
Taken with 32 inch scope SBIG STL 1001E camera, 5 min subs, 60 min total.
NGC 7448 (Image by Doug Paul)
Cannon 80D, 600mm f4.0 lens (150mm aperture), iso 800,
71×30 sec = 35.5 minutes, plate scale 1.3 arc-sec/pixel, north up.