Celestial hemisphere:  Northern  ·  Constellation: Canes Venatici (CVn)  ·  Contains:  IC 3668  ·  NGC 4618  ·  NGC 4625
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NGC 4618 - Arp 23 One-armed Spiral., 



    
        

            astroeyes
NGC 4618 - Arp 23 One-armed Spiral.
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NGC 4618 - Arp 23 One-armed Spiral.

Getting plate-solving status, please wait...
NGC 4618 - Arp 23 One-armed Spiral., 



    
        

            astroeyes
NGC 4618 - Arp 23 One-armed Spiral.
Powered byPixInsight

NGC 4618 - Arp 23 One-armed Spiral.

Equipment

Imaging Telescopes Or Lenses
Orion Optics UK DX 250
Imaging Cameras
Starlight Xpress H9C
Mounts
Vixen GPDX w/ SS2K
Software
PHD · Astroart 3 · NEAT · PixInsight
Guiding Cameras
KWIQ Guider

Acquisition details

Dates:
May 21, 2009
Frames:
72×60(1h 12′)
Integration:
1h 12′
Avg. Moon age:
26.22 days
Avg. Moon phase:
11.88%

Basic astrometry details

Astrometry.net job: 6575933

RA center: 12h41m32s.9

DEC center: +41°1402

Pixel scale: 1.125 arcsec/pixel

Orientation: 155.455 degrees

Field radius: 0.261 degrees

Resolution: 1335x1005

File size: 293.6 KB

Locations: Home, Weymouth, Dorset, UK, United Kingdom

Data source: Backyard

Description

Here's a nice Arp galaxy. This time Arp 23, very close to M94. Arp 23, or ngc 4618 is an example of a one-armed spiral. Interestingly, there is another one-armed spiral in the same field of view, ngc 4625.

ngc 4618 is mag. 11.2, size 4.2' x 3.4' and is classified as SB(rs)m.

ngc 4625 is mag. 12.9, size 2.2' x 1.9' and is classified SAB(rs)m pec,

where the (rs) indicates a 'ring shaped' spiral and the m refers to the galaxies irregularity.

There is a little anonymous spiral between the 2 big galaxies.

This night was good and I managed about 72 minutes exposure on this one through the 10", the same night I imaged M94, before the clouds rolled in.

Comments

Sky plot

Sky plot

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NGC 4618 - Arp 23 One-armed Spiral., 



    
        

            astroeyes