DEEP- SKY TOUR

Take a swan dive into the neb­u­lae nestling to the north­west of Cygnus

Sky at Night Magazine - - THE SKY GUIDE JULY -

Tick the box when you’ve seen each one 1 NGC 7000

We start this month’s tour with the North Amer­ica Ne­bula, NGC 7000, so called be­cause its shape re­sem­bles that of the North Amer­i­can con­ti­nent. This is a large ob­ject mea­sur­ing 120x100 ar­cmin­utes and con­se­quently a dif­fi­cult tar­get for tele­scopes. Lo­cated 3° east of Deneb (Al­pha (_) Cygni), it’s just about vis­i­ble to the naked eye from a dark-sky site. NGC 7000 con­tains a mul­ti­tude of stars and star clus­ters all em­bed­ded within its glow­ing ne­bula. The bright­est re­gion around the ‘Gulf of Mex­ico’ is re­ferred to as the Cygnus Wall and it is the most likely part of the ne­bula to be vis­i­ble through a small tele­scope us­ing a low-power eyepiece. The ne­bula’s dis­tance isn’t pre­cisely known but is thought to be in ex­cess of 1,600 lightyears away. SEEN IT

2 IC 5067

IC 5067 is lo­cated im­me­di­ately west of NGC 7000. It is known as the Pel­i­can Ne­bula be­cause it re­sem­bles the ap­pear­ance of an east-fac­ing pel­i­can in pho­to­graphs. This is vis­ually trick­ier to see than its con­ti­nen­tal com­pan­ion, the eas­i­est part be­ing the area con­tain­ing the head and beak, which lies 15 ar­cmin­utes off the east ‘coast’ (ie, west) of NGC 7000. The Pel­i­can and North Amer­ica Neb­u­lae are part of the same glow­ing hy­dro­gen gas cloud, their dis­tinc­tive shapes cre­ated by a dark fore­ground molec­u­lar cloud. Binoc­u­lars or a small tele­scope at 15x-20x mag­ni­fi­ca­tion and fit­ted with a UHC fil­ter should pro­vide you with a de­cent view of NGC 7000 as well as the Pel­i­can’s head. SEEN IT

3 NGC 7027

Our next tar­get is plan­e­tary ne­bula NGC 7027, lo­cated 1.7° south and 0.4° east of mag. +3.7 yel­lowor­ange Xi ( ) Cygni, it­self lo­cated just east of NGC 7000. This mag. +10.4 plan­e­tary has an ap­par­ent di­am­e­ter of 14 arc­sec­onds. Through a 6-inch scope at 50x mag­ni­fi­ca­tion it re­sem­bles a dim 9th mag­ni­tude star. In­creased power shows an oval shape with larger aper­tures re­veal­ing a green-hued plan­e­tary that looks vaguely rec­tan­gu­lar. Thanks to the Hubble Space Tele­scope we now know this is a plan­e­tary ne­bula in the very early stages of de­vel­op­ment, around 600 years old. NGC 7027 is one of the small­est plan­e­tary neb­u­lae known, mea­sur­ing less than 0.2 lightyears across. The cen­tral star shines at mag. +16.3. SEEN IT

4 NGC 7039

you’ll find the 8th mag­ni­tude open clus­ter NGC 7039. You might think that finding a mag. +7.6 open clus­ter would be a rel­a­tively easy task but, sadly, that’s not the case in this in­stance. The is­sue here is not the bright­ness of the open clus­ter but rather the star-rich na­ture of the sur­round­ing sky – it’s like stel­lar cam­ou­flage. The 100 or so mem­bers of the clus­ter sim­ply blend into their sur­round­ings far too well! The clus­ter ap­pears to be about 25 ar­cmin­utes across and is mostly pop­u­lated by stars be­tween mag­ni­tudes +11 and +13. A few brighter mem­bers ap­pear to bor­der the cen­tral core. Use a low power to see NGC 7039 at its best. SEEN IT

5 NGC 7048

Next up is plan­e­tary ne­bula NGC 7048. This is the faintest of this month’s tour ob­jects shin­ing away with an in­te­grated mag­ni­tude of +12.1. Com­bined with a rea­son­able ap­par­ent di­am­e­ter of around 1ar­cminute, NGC 7048’s sur­face bright­ness is quite low and this makes it some­thing of a chal­lenge to ob­serve. Con­se­quently you’ll need a tele­scope with at least 10-inches of aper­ture. It sits 45 ar­cmin­utes north­east of NGC 7039 and there’s a mag. +10.5 star (TYC 35894652-1) just south­east of the ne­bula’s cen­tre. At higher pow­ers, the ne­bula ap­pears like a faintly glow­ing disc with the outer edge ap­pear­ing as bro­ken arcs. The in­ter­nal ‘sur­face’ of the disc ap­pears dis­tinctly mot­tled with averted vi­sion. SEEN IT

6 NGC 7026

Our fi­nal ob­ject for this month’s tour is NGC 7026, an­other plan­e­tary ne­bula. We’ve al­ready had a look at the rec­tan­gu­lar NGC 7027 and the cir­cu­lar NGC 7048 but NGC 7026 is more ir­reg­u­lar in ap­pear­ance. It’s a bipo­lar ne­bula with two roughly sym­met­ri­cal, elon­gated lobes, their long axes par­al­lel to one an­other. The ne­bula is known as the Cheese­burger Ne­bula be­cause the lobes are sep­a­rated by a dark lane that re­sem­bles the fill­ing of a burger. It shines at mag. +11 and ap­pears around 25 arc­sec­onds across. Larger aper­tures at high pow­ers re­veal that the ‘cheese­burger’ is sur­rounded by a glow­ing haze. The ‘buns’ also show brighter patches at high mag­ni­fi­ca­tion. NGC 7026 is lo­cated 2° north­west of NGC 7048. SEEN IT

Mag. +12.1 NGC 7048 may be faint, but this un­usual plan­e­tary ne­bula is worth the ef­fort you need to put in to ob­serve it

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