Cookie consent

AstroBin saves small pieces of text information (cookies) on your device in order to deliver better content and for statistical purposes. You can disable the usage of cookies by changing the settings of your browser. By browsing AstroBin without changing the browser settings, you grant us permission to store that information on your device.

I agree
Contains:  M 4, M4, NGC 6121
Getting plate-solving status, please wait...


            Gary Imm
Powered byPixInsight


Technical card

Imaging telescopes or lenses:Orion EON 130mm ED Triplet APO

Imaging cameras:ZWO ASI1600MM-Cool

Mounts:Astro-Physics Mach1GTO

Guiding telescopes or lenses:Orion 60mm Guidescope

Guiding cameras:Orion StarShoot AutoGuider Pro Mono

Focal reducers:Orion 3" Field Flattener

Software:Main Sequence Software Sequence Generator Pro PHD2PixInsight 1.8


Accessory:ZWO EFW

Dates:July 1, 2017

Blue: 20x30" (gain: 139.00) -15C bin 1x1
Green: 20x30" (gain: 139.00) -15C bin 1x1
Red: 20x30" (gain: 139.00) -15C bin 1x1

Integration: 0.5 hours

Avg. Moon age: 7.83 days

Avg. Moon phase: 54.72% job: 1641380

RA center: 16h 23' 36"

DEC center: -26° 31' 31"

Pixel scale: 0.851 arcsec/pixel

Orientation: -79.756 degrees

Field radius: 0.503 degrees

Resolution: 3712x2088

Locations: Backyard (Mag 20.8 - New Moon), Onalaska, Texas, United States

Data source: Backyard


This object is one of the most open, or loosely constructed, of all globular star clusters. At a distance of about 7,200 light-years from Earth, M4 is also one of the closest Messier Objects to Earth. Note the contrast of hot (bluish) and cool (reddish) stars surrounding the core. You can easily see a bar structure horizontally across its central core region, consisting of 11th magnitude stars. Messier 4 has roughly the same apparent size as our full moon and is visible to the naked eye, but only in exceptionally good conditions. This object is relatively small for a globular cluster and contains about 20,000 stars, which is far fewer than the largest globular clusters which can contain up to 500,000 stars.



Gary Imm
License: None (All rights reserved)

Sky plot

Sky plot




            Gary Imm

In these public groups

Cloudy Nights
The refractors!