Challenge #2 – C62, Spiral Galaxy in Cetus
| Target | Type | R. A. | Dec. | Constellation | Magnitude | Size |
| C62 (NGC 247) | Spiral Galaxy | 00h 22m 08s | +20° 45′ 38″ | Cetus | +9.1 | 20×6 arcmin |
Overview
The legendary William Herschel discovered this galaxy as “a streak of light” in October 1784.
Today, we know that C62, also known as NGC 247, is a relatively bright, nearly edge-on galaxy over 11 million light-years away. It is gravitationally bound to NGC 253, the Sculptor Galaxy, which is the 65th entry in the Caldwell Catalog.
It’s a giant in its own right, at 70,000 light-years across. What makes it unusual is the large void that we can see in the image below as a fainter oval area on the galaxy’s right. This void is rich with older red stars but not so with the younger, bluer variety.
Finder Charts
The first sky chart, from SkySafari 6, shows the view at 10 pm in the middle of November, looking east. Stars are shown to magnitude 5.0 but the moon and planets are not shown.
The brightest, most obvious constellations visible are Orion and the Great Square of Pegasus. We’re looking for Cetus the whale, which is south of the Great Square. I’ve marked C62 as a green oval and it’s labelled as NGC 247.
Zooming in the the head of Cetus but keeping stars still limited to magnitude five, you can see that our galaxy is south of one of this constellation’s brightest stars, Deneb Kaitos, which shines at magnitude 2.0.
What we now need to identify is a triangle of magnitude-five stars about four degrees south of Deneb Kaitos. These are visible with the naked eye but much easier to see with binoculars. They are each labelled on the chart below as HR 197, 210, and 220. The chart itself shows stars as faint as magnitude seven.
HR 220 is in the same 1.5° field of view as the galaxy NGC 247.
We’re now ready to attempt observation of this nebula.
Individual Telescope Views
The following views will help you find C62 in different telescope types by presenting the images as your telescope will show them. The first image is with a black sky and white stars, the second picture is the same image but presented in inverse monochrome. Black stars on a white background is often easier to use at the telescope. Each image can be clicked on for a full-screen version. Stars are shown to magnitude 10.0 and the starHR220 is the bright one near the south marker of the 1.5° field of view circle shown in each image.
Upright View – This is what your eyes see unaided and through a reflex or red-dot finderscope
Upside-down view – This is what reflectors and magnifying finders show, and refractors / Cassegrains without a star diagonal
Mirrored View – Refractors and Cassegrain models with a star diagonal show this view
Observation
Observe with a dark sky as your backdrop and you’ll enjoy this bright galaxy even in a smaller telescope. At low magnification, you can see the core of this slender ‘needle of light’ is brighter than the periphery. Between the edge and core is a strong mottled texture of fuzzy light.
Higher magnitude brings more definite texture to the view. Reminiscent of a spindle, there is a tenth magnitude star at its southern tip. It’s the southern half of this galaxy that shines the brightest and invites us to linger over it using direct and averted vision to tease out structural elements.
PDFs for Printing
Each of the star maps above is reproduced as a pdf below. Each star map has a number in [square brackets] beneath it which corresponds to the file number below. If you want image [C62-1], for example, click the ‘download’ button next to it below and you’ll be able to open it as a printable pdf.