NGC 5474, et al

From: Bill Ferris (billferris_at_aol.comic)
Date: 06/21/04 

Date: 21 Jun 2004 00:16:32 GMT

     Here, are some notes from last Friday night. I was observing with the
10-inch, f/4.5 Starfinder from Anderson Mesa, the Lowell dark sky site
southeast of Flagstaff.

NGC 5474: http://members.aol.com/billferris/n5474.html
     This galaxy is among several in the neighborhood of M101. My sketch
presents a 129X view in my 10-inch equatorial Newtonian. NGC 5474 covers a
10'x5' area at the center of the drawing. the core and main disk appear roughly
5' in diameter. With averted vision a fairly large spiral arm is seen arcing
westward from the disk. A second, shorter arm reaches to the east-southeast.
Neither appears on DSS images, but this is a loose spiral galaxy and arms
should range far from the core. A 14th magnitude star dimly glows in the
foreground just north of the central disk region. A tight triangular grouping
of 11th and 12th magnitude stars is seen about 9' to the northwest. The 10.8
magnitude spiral galaxy is about 26' northwest of 7.1 magnitude HD 123518. M101
lies beyond the field boundary to the northwest.

     Regarding the spiral arms, has anybody else observed these in NGC 5474?

NGC 3718, NGC 3729: http://members.aol.com/billferris/n37183729.html
     This galaxy pair hangs from the bowl of the dipper like water drops from a
laddle. My drawing presents a 129X view in the 10-inch. NGC 3718 is west of
center. This 10.7 magnitude barred spiral has an interesting dark lane
structure. The galaxy is split in two triangular sections with a barely
discernable dark lane bisecting them along a northwest-to-southeast track. It
covers a 7'x3' area. A pair of 11th magnitude GSC stars are close-set at the
southern extent of this galaxy's soft glow. Another 11th magnitude star marks
the northern limit. NGC 3729 is visible just 11' to the east, very near yet
another 11th magnitude GSC star. This 11.4 magnitude peculiar galaxy covers a
3'x2' area. You'll find NGCs 3718 and 3729 about 3 degrees west-southwest of
2.4 magnitude Phad.

     Any other observations of the dark lane in NGC 3718?

NGC 6309 "Box Nebula": http://members.aol.com/billferris/n6309.html
     Tiny, can't begin to describe this one. At just 45"x20" in size, NGC 6309
is very difficult to detect at less than high power. I used 388X to make the
observation recorded in my sketch. A 12th magnitude foreground star is
centered. The planetary extends south-southeast over a distance of some 45".
This dainty ribbon of light is just 20" wide. The south end of the nebula
appears slightly tapered, making NGC 6309 look something like a parallelogram.
But the end closest to the star looks squared.
     NGC 6309 is sometimes called the Box nebula. I can see the resemblance in
some images but, considering the challenging nature and irregular form of this
miniscule planetary, it doesn't really to fit the mold of objects meriting a
popular name. You'll find this 10th magnitude object in eastern Ophiuchus,
almost 2 degrees west of 4.3 magnitude 53 (Nu) Serpentis.

     At what aperture, have folks seen this planetary as a "box?"

Regards,

Bill Ferris
"Cosmic Voyage: The Online Resource for Amateur Astronomers"
URL: http://www.cosmic-voyage.net
=============
Email: Remove "ic" from .comic above to respond

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