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:  Little Gem, NGC 6445, NGC 6440
Getting plate-solving status, please wait...
NGC 6445 and NGC 6440, 





    
        

            Gary Imm
NGC 6445 and NGC 6440

NGC 6445 and NGC 6440

Technical card

Resolution: 3000x2303

Dates:April 19, 2019April 20, 2019April 21, 2019

Frames:
Astrodon Blue 31mm Gen2 I-Series: 30x60" (gain: 139.00) -20C bin 1x1
Astrodon Green 31mm Gen2 I-Series: 30x60" (gain: 139.00) -20C bin 1x1
Astrodon Ha 31mm 5nm: 24x300" (gain: 300.00) -20C bin 1x1
Astrodon OIII 31mm 3nm: 24x300" (gain: 300.00) -20C bin 1x1
Astrodon Red 31mm Gen2 I-Series: 30x60" (gain: 139.00) -20C bin 1x1

Integration: 5.5 hours

Avg. Moon age: 15.88 days

Avg. Moon phase: 97.76%

Astrometry.net job: 2694839

RA center: 267.290 degrees

DEC center: -20.166 degrees

Pixel scale: 0.718 arcsec/pixel

Orientation: 48.714 degrees

Field radius: 0.377 degrees

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

Data source: Backyard

Description

This field of view captures two objects, a planetary nebula (NGC 6445) and a globular cluster (NGC 6440), in the southern constellation of Sagittarius at a declination of -20 degrees. It is rare to be able to see a planetary nebula and a globular star cluster in the same field of view. This image combines narrowband and RGB to capture both nebula detail and star color.

The planetary nebula spans 3 arc-minutes in our apparent view. It is one of the largest PN (and therefore also one of the oldest) at a true diameter of 4 light years. It lies 4,500 light-years distant. It has two nicknames - Box Nebula and Little Gem Nebula - which both stem from its RGB projection as a rectangular box, seen in this image as the bright white outline. At least two other PN are also nicknamed the Box Nebula - NGC 6309 and NGC IC 4406.

The overall structure of this nebula is very similar to that of NGC 40. Like NGC 40, the white box is the cross-section of the torus of dense material which originally contained the bi-polar PN gas outflow. Our perspective is at 90 degrees, a side view. Also like NGC 40, the gas flow has burst through the ends and expanded into a butterfly shape. NGC 40 is a multi-polar PN and so is this one, as seen by the various axes of gas outflows. A recent scientific study has concluded that this is a quadrupolar PN, but it looks like a bit more than that to me.

The globular cluster NGC 6440 lies 6x further away, at 24,000 light-years distant. The orange tint is very interesting, presumably from a significant amount of dust in that distant direction. The outer extent of the cluster is very unsymmetric, with a void area seen on the left side of the cluster. Again, I assume that this is due to dust.

Comments

Author

GaryI
Gary Imm
License: None (All rights reserved)
1472
Like

Sky plot

Sky plot

Histogram

NGC 6445 and NGC 6440, 





    
        

            Gary Imm