NGC 3675, NGC 3521, NGC 3640, NGC 3810 Lakeside Observing

To go along with the pictures, I've processed some of my sketches so here they are with their reports. Something new I think I'll start is an object of the month and it is included below.

NGC 3675 Spiral Galaxy in Ursa Major
10:25p.m. MDT/04:25 UT
Lakeside Utah, West Desert
Seeing: I Antoniadi Scale, clear, brisk temperature, slight wind.
LVM: 6.9
RA 11h 26m 1s
Dec. +43 35m
Mag. 10.2
Size: 6.2' x 3.2'
Orion XT10
13mm Stratus @ 92x

Faint core with direct vision, and with averted vision slightly off the core, the core shows a more stellar core. Halo is evident around the core with direct vision. Averted vision shows more of the halo's size. Halo is diffused on the edge. Very, very faint star just above and to the west, taking averted vision to see it. Very evident face on with more time observing it, the core sticks out and the core is slightly brighter than the surrounding halo. Shape is round.

NGC 3521 Mixed Spiral Galaxy in Leo
11:55p.m. MDT/05:55 UT
Lakeside, Utah, West Desert
Seeing: I Antoniadi Scale, clear, crisp, no wind.
RA 11h 05m 8s
Dec. -00 02m
Mag. 9.1
Size 11.7' x 6.5'
Orion XT10
13mm Stratus @92x, 5mm Hyperion @ 240x (sketches at 240x)

Beautiful galaxy, one that I bet is often overlooked by observers. Very bright core, clear and crisp with an oval halo surrounding it. At 92x an arm on the SE side is evident, hinted at. Mottling on the NW to NE side also. Arm is seen best with averted vision and the size is shown best with averted vision also. 240x brings out the shape of the halo and the core shines really bright, much brighter than the halo and a possible dark lane (?) is evident wrapping under the core to the SW. Please see this while Leo is positioned so well for this object. My object of the month!

NGC 3640 Elliptical Galaxy in Leo
12:25p.m. MDT/06:25 UT
Seeing: I Antoniadi Scale, clear and cold, humidity rising.
RA 11h 21m 1 s
Dec +03 14m
Mag. 10.4
Size: 4.6' x 4.1'
Orion XT10
13mm Stratus

Dark adaptation is a must along with excellent transparency and averted vision to make out this galaxy. Averted vision reveals a faint stellar core that disappears with direct vision. The galaxy is roundish in shape with a faint outer halo that surrounds the core. The edges of the halo are diffused. The core seems only viewable during times when the seeing improves, much like viewing a planet. Luckily it is great seeing and decent transparency tonight, well until that humidity builds.

NGC 3810 Spiral Galaxy in Leo
12:52a.m. MDT/06:52 UT
Lakeside Utah, West Desert
Seeing: I on Antoniadi Scale, clear, cold and humidity is really rising.
RA 11h 41m 00s
Dec. 11 28m
Mag. 10.8
Size 3.8' x 2.6'
Orion XT10
13mm Stratus @ 92x

The galaxy appears at first to be a round, diffused blob. With patience that changes as the core is viewable. The core is just slightly brighter than the surrounding halo around it. With even more patience the core grows and the galaxy takes on an irregular shape. It is a faint object best seen at a dark site.

I've debated lately whether to continue with the Herschel 400. In some ways I grow tired of viewing these faint objects with no real opportunity to sketch in detail. Then this last time out I realized how much more detail my eyes are picking up in this quest and I'm going to stick with it. I wonder if others reached that point with this list?


  1. Yes, a lot of faint fuzzies in the H400! I waited until I completed the 18" before pressing through the list. I would deliberately not read about the object until I had viewed it, to hit each object cold. There would be a number of The-Usual-12thMag-Fuzzies in a row, then... nice... a pleasant surprise object with more to see.

  2. Andrew,

    I agree with you about not reading about the object until after I observe it for myself. I also totally agree that there are a lot of 12th mag. and then a nice one comes along. With May's observing time closing fast for DSO's and weather not cooperating, I have to decide whether to bag the rest of April's list, go on to May's (what I'll probably do) or try to plug through the end of May's list. Then on to the next one. Thanks for posting Andrew and for letting me know the marathon is worth it.