NGC 7023 is a reflection nebula located in the west central section of the far northern constellation of Cepheus. The nebula contains at its centre an extremely young star named V380 Cep (mag. +7.1) which is believed to have burst into life just 5,500 years ago. Since still incredibly young there is plenty of local dust surrounding the star and when starlight hits the dust it's reflected to become the visible nebula.

NGC 7023 is located 6 degrees northwest of the brightest star in Cepheus, Alderamin (α Cep - mag. +2.5) with third magnitude Alfirk (β Cep) positioned about 3.5 degrees to the northeast. Only a degree east-northeast of NGC 7023 is Mira type variable star T Cep, which fluctuates between magnitudes +5.2 and +11.3 over a period of 388.14 days. A faint eleventh magnitude barred-spiral galaxy, NGC 6951, is positioned two degrees southwest of NGC 7023.

The nebula is also known as the Iris Nebula and is number 4 in the Caldwell catalogue. It was discovered by Sir William Herschel on October 18, 1794.

NGC 7023 - Reflection Nebula (credit - Hunter Wilson)

Finder Chart for NGC 7023 (credit - freestarcharts)

Finder Chart for NGC 7023 - pdf format (credit - freestarcharts)

NGC 7023 shines with an apparent magnitude of +6.8 and is theoretically bright enough to be visible with binoculars but its large apparent size (18 arc minutes) and diffuse nature makes this an almost impossible task. It's also difficult to spot with 80mm (3.1-inch) or 100mm (4-inch) refractors, at best appearing faint, misty and without detail. The best views of NGC 7023 are reserved for large scopes. With a 250mm (10-inch) or larger instrument the nebulosity is fairly easy to spot and under good conditions a wealth of intricate details such as knots and dark patches are revealed.

Of course, the true beauty of NGC 7023 is revealed in images and long exposure photographs. They show much fine detail embedded in a characteristic blue light caused by reflected starlight off dust grains.

NGC 7023 is 1,300 light-years distant and has a spatial diameter of 7 light-years. It's best seen from northern temperate locations where it appears high in the sky during October, November and December. From latitudes north of +22 degrees the nebula is circumpolar and therefore visible all year round. From southern latitudes it appears at best low down or never even rises at all.

NGC 7023 Data Table

NGC7023
Caldwell4
NameIris Nebula
Object TypeReflection Nebula
ConstellationCepheus
Distance (ly)1,300
Apparent Mag.+6.8
RA (J2000)21h 01m 36s
DEC (J2000)+68d 10m 10s
Apparent Size (arc mins)18 x 18
Radius (light-years)3.5
Age (years)5,500
Other NameLBN 487
Notable FeatureReflection nebula illuminated by mag. +7.4 star V380 Cep (SAO 19158)

Sky Highlights - March 2017

Comet
Comet 41P/Tuttle-Giacobini-Kresak now visible with binoculars as it heads towards perihelion

Mercury
Mercury heading towards greatest elongation east

Minor Planet
Vesta now visible with binoculars and small telescopes.

The Planets
This Month's Guide

Algol Minima
Algol eclipse dates and times for March 2017

Northern Hemisphere
Evening
West:- Venus (mag. -4.8 to -4.1 - first half of month), Mars (mag. +1.3 to +1.5), Uranus (mag. +5.9), Mercury (mag. -1.5 to -0.4 - second half of month)
Midnight
Southeast:- Jupiter (mag. -2.3 to -2.5)
Morning
Southwest:- Jupiter
Southeast:- Saturn (mag. +0.5)

Southern Hemisphere
Evening
West:- Venus (first half of month), Mars, Uranus
Midnight
North:- Jupiter
East:- Saturn
Morning
West:- Jupiter
Northeast:- Saturn
East:- Neptune (mag. +8.0 - second half of month)

Deep Sky
Naked eye / binoculars:-
Melotte 111 - Mel 111 - The Coma Star Cluster (Open Cluster)
Messier 44 - M44 - The Praesepe (Open Cluster)

Telescopes:-
Messier 67 - M67 - Open Cluster
Messier 51 - M51 - The Whirlpool Galaxy (Spiral Galaxy)
Messier 97 - M97 - The Owl Nebula (Planetary Nebula)
Messier 101 - M101 - The Pinwheel Galaxy (Spiral Galaxy)
Messier 65 – M65 – Spiral Galaxy
Messier 66 - M66 - Intermediate Spiral Galaxy
Messier 95 - M95 - Barred Spiral Galaxy
Messier 96 - M96 - Intermediate Spiral Galaxy
NGC 4244 - Spiral Galaxy
NGC 4565 - Needle Galaxy - Spiral Galaxy

Shop at Amazon US

Shop at Amazon US

Current Moon Phase

CURRENT MOON

Contributions

If you like the website and want to contribute to the running costs then please do so below. All contributions are most welcome.