Targets for November 26–December 3, 2015
Small telescope: Open cluster NGC 1342
Large telescope: Spiral galaxy NGC 1313
Large telescope: Barred spiral galaxy NGC 1398
Swimming with stars
This week’s small-telescope target is open cluster NGC 1342 in Perseus. You’ll find it 5.7° west-southwest of magnitude 3.0 Epsilon (ε) Persei.
This stellar grouping shines brightly just out of the range of human vision from a dark site. It boasts a magnitude of 6.7 and a diameter of 17′. That means it covers 30 percent as much area as the Full Moon.
Through a 4-inch telescope at a magnification of 100x, you’ll spot three dozen stars evenly distributed across the face of this cluster. A 12-inch scope shows lines and arcs formed by the brighter members and brings 75 more stars into view.
Bright, but far to the south
This week’s first large-scope object is spiral galaxy NGC 1313. This target is one of the southern sky’s showpiece galaxies, but you’re forgiven if you haven’t heard of it. NGC 1313 sits in the southwest corner of Reticulum, 3.2° southwest of magnitude 3.8 Beta (β) Reticuli.
At magnitude 8.7, this spiral rates as “bright” on the galaxy scale. Its light spreads out, however, over an area of 11.0′ by 7.6′.
Through an 8-inch telescope, the first feature you’ll notice is the thick bar that orients north-south. The bar has a slight bulge at its center. A spiral arm extends eastward from the north end of the bar and westward from the south end.
The eastward bar has two distinct sections divided by a dark region. You’ll also notice many bright knots along the arms and the bar. Those are star-forming regions. Moreover, a spiral arm divided into two elongated sections extends at a right angle to the east from the north end of the bar. And all this is visible through an 8-inch scope!
If you use a 14-inch or larger instrument on this object, look 16′ southeast of NGC 1313 for the magnitude 13.8 edge-on spiral NGC 1313A.
Galaxy in the furnace
This week’s second large-telescope target is barred spiral galaxy NGC 1398 in Fornax. You’ll find this object 1.6° due north of magnitude 6.0 Tau (τ) Fornacis.
NGC 1398 shines at magnitude 9.7 and measures 7.2′ by 5.2′. This galaxy’s core is so bright that it masks its delicate spiral arms when viewed through small telescopes.
In fact, I’ve only caught glimpses of the arms when I’ve observed NGC 1398 through a 14-inch telescope at high power. Here’s an object that really will reward views through scopes with apertures 20 inches of larger.
This object’s bar runs roughly north-to-south and is only slightly fainter than the rest of the wide central region.
Expand your observing at Astronomy.com
Check out Astronomy.com’s interactive StarDome to see an accurate map of your sky. This tool will help you locate this week’s targets.
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