The Little Fox
25 July 2017
The Kalahari has been my finest site for observing the little fox, Vulpecula. Not only because of the Bortle Black skies, or because of the amazingly transparent and steady skies… but because my favourite little carnivore, the enchanting bat-eared fox, lives in the Kalahari and last night while I was exploring Vulpecula a pair of them (they are monogamous animals) were communicating out in the dark with their typically soft contact calls, whines and chirps; although now and then one of them gave a surprisingly loud bark.
The bat-eared fox is no ordinary fox! It doesn’t raid chicken coops at night because it is the only insectivorous member of the canid family. Its favourite insect is the harvester termite which it licks up by the thousands while feeding at night. (These beautiful little creatures play an important role in termite control. A single bat-eared fox can eat approximately 1.15 million termites each year.) Besides termites, bat-eared foxes eat all manner of other insects and beetles (along with any other opportunistic prey; it’s a harsh life living in the Kalahari, one eats what one can find.)
Their huge ears are designed to detect even the tiniest insects moving around, and using their bat-like ears as twin satellite dishes they can detect beetle larvae that are a foot underground. It is quite enchanting to see these beautiful little animals standing with their heads cocked, ears pointing to the ground, listening for the sound of grubs and termites below the ground – then suddenly pouncing forward and rapidly digging up a nice high-protein meal.
Vulpecula is just as enchanting as the little bat-eared fox. Despite its diminutive size, it is a delightful little constellation to explore. Besides containing the spectacular Dumbbell Nebula, truly one of the great showpieces of the sky, and the gorgeous gathering of bright stars, Al Sufi’s Cluster, it has a surprisingly large number of open clusters, a small collection of bright nebulae, some very nice double and triple stars, some faint galaxies at its far eastern end, a few little treasures tucked away here and there, and lovely star fields that are a delight to sweep through with binoculars.
Vulpecula is also famously home to the first pulsar ever discovered, PSR B1919+21, first observed by Jocelyn Bell Burnell and Antony Hewish in 1967 – half-jokingly nicknamed LGM-1 for “Little Green Men”, because the pulsing radio signal was so regular it seemed to be a sign of intelligent life. When one looks at the spot in the sky wherein lies the famous pulsar, ticking away like a cosmic metronome, it is unbelievable that Jocelyn Bell Burnell made one of the greatest astronomical discoveries of the 20th century – what she called her “scruffy signal” forever changed our image of the cosmos – yet the Nobel committee snubbed her when they awarded Antony Hewish, and another researcher, Martin Ryle, the Nobel Prize for Physics, in 1974, for the discovery.
As a charming aside, graphic designer Peter Saville used the image of the successive pulses from the pulsar for his iconic cover for the English post-punk band Joy Division’s 1979 debut studio album Unknown Pleasures. The image came from the 1977 edition of the Cambridge Encyclopedia of Astronomy, and in the context of this album, the pulsar is known by its original designation, CP 1919. (Cambridge Pulsar 1919, with the “1919” being the pulsar’s right ascension).
Observations
16″ f/5 Dobs at magnifications of 150x, 228x and 333x
10×50 binoculars
With the two little foxes keeping me company in the dark with their own little scruffy signals, I spent many enchanting hours exploring Vulpecula. It was magical to listen to the little foxes while exploring the little fox. How much better could a night under the stars get?
Al Sufi’s Cluster
RA 19 25 24 Dec +20 11 00
I began by sweeping through Vulpecula’s rich frosty Milky Way fields with my binoculars; they are simply breathtakingly wondrous. Of course, the binocular highlight is the glorious asterism, Al Sufi’s Cluster; here in the southern hemisphere floating not-upside down in a vast dark lane of interstellar dust, its ten bright stars appearing almost pure white in the binoculars. (Naked eye it is visible as a small frosty patch in this vacant area of the Milky Way.) It may not be an open cluster, but it sure looks convincing! And it has a couple of lovely doubles – 4 Vulpeculae, the southernmost star in the hook, is a lovely triple; and Σ2521, is a really nice quadruple. (It does look like its common nickname – the Coathanger – but I confess to me it will always be Al Sufi’s Cluster, named for the Persian astronomer who first described it in his Book of Fixed Stars in 964.}
Anser – Alpha Vulpecula
RA 19 28 42.3 Dec +24 39 53.6 Mag 4.4
Vulpecula’s brightest star, magnitude 4.4 Anser, is named for the goose in the fox’s mouth with which the constellation was originally constructed – Vulpecula cum Ansere, the Fox with Goose – although, having lost the rest of the goose, the beautiful ruddy red giant looks in the telescope like a juicy termite in the jaws of a bat-eared fox. It is an optical double, with a white 6th magnitude companion; the contrasting colours making it a gorgeous sight.
Then it was straight to the little fox’s showpiece…
NGC 6853, M27 Planetary Nebula
RA 19 59 36.3 Dec +22 43 16 Mag 7.6 Size 402″ Mag cent * 13.9
No matter how many times I look at this planetary nebula, I am awestruck by its indescribable beauty. It is truly one of the night sky’s great showpieces, gorgeous at every magnification. In my 10×50 binoculars it appears as a small scrap of palest grey silk adrift in the Milky Way.
At low magnification in the telescope, it is one of those rare objects that appears three-dimensional, hanging out in front of the stars that are scattered around it, like a glorious silver pendant hanging from a beautiful array of stars in the Milky Way.
At higher magnification its two bright dumbbell lobes, oriented NNE-SSE, are full of incredibly silky bright and less-bright patches, a glowing play of light that is breath-taking. Two prominent bright patches glow near the edge of the SSW lobe, which itself has a bright outer rim. I can count five stars superimposed on the planetary nebula.
The mag 13.8 central star is easy to see. I find it incredibly moving to be able to see a dead star wrapped in its shroud. (As did a sixteen year old girl, on holiday in the Kalahari from Johannesburg, who came to look at the stars the other night. When I showed her this nebula and explained what she was seeing, she stared and stared, then said it was getting very blurry. I told her to adjust the focus a bit… but she replied that it wasn’t getting blurry because it was out of focus, it was because she had tears in her eyes at the sight of it.)
With a long careful look, I can see two larger, very faint, gossamer side lobes that swoop out gracefully and fill the dumbbell shape. They appear as if they are transparent, their gossamer quality making it seem as if I am seeing straight through them and staring into the deepest voids of space behind them. Very unusual; very beautiful.
Most people report seeing this strikingly beautiful planetary as variations of green. To my eye it steadfastly remains a gorgeous silvery-grey with just a hint of blue mixed in.
John Herschel gave it its nickname when he described it thus: “…an unresolved nebula, shaped something like an hour-glass, filled into an oval outline with a much less dense nebulosity. The central mass may be compared to a vertebra or dumb-bell…” When Waldo, my dog, and I go for our walks in this vast scrubby desert we often come across bones bleached pure white by the relentless sun. And to be frank, JH’s description of the planetary nebula looking like a vertebra pretty much nails it.
Sticking with planetary nebulae, I hopped over to…
NGC 6842 Planetary Nebula
RA 19 55 02.2 Dec +29 17 21 Mag 13.1 Size 57″ Mag cent * 15.9
One would be forgiven thinking that looking at this little chap after the spectacular M27 might be a touch disappointing. But not. By comparison it’s but a smudge of a glow, but in its own right, it’s a little treasure – appearing as a fairly bright, moderately large diaphanous glow, not quite round and with lovely soft edges that simply melt away into the dark sky. Its very faint mag 15.9 central star flickered into view very briefly, but alas it was more of an impression than a certainty. It lies in a rich star field, and a pretty star chain runs past the PN’s eastern edge.
IC 4954/55 Bright Nebula
RA 20 04 48.0 Dec +29 15 00 Mag – Size 3′
This is another of Vulpecula’s little treasures. IC 4954/55 form an attractive compact pair of nebulae. IC 4954 is a very small, faint, round, soft silky-grey glow of nebulous light that appears to surround a mag 13 star.
IC 4955 is the larger and slightly brighter of two, a faint silky glow that appears to surround a mag 12 star.About a dozen stars are scattered over the nebulosity, gathered in two irregular but parallel rows; a very pretty little arrangement. There were no contrast gains with either an OIII or UHC filter. Roughly 4’ NE is a striking little asterism that looks somewhat like a little propeller. This whole package really is a lovely sight.
NGC 6823 Open Cluster
RA 19 43 09 Dec +23 18 00 Mag 7.1 Size 7′
NGC 6820 Emission Nebula
RA 19 42 28.0 Dec +23 05 17 Mag – Size 40′ x 30′
The open cluster, NGC 6823, is a lovely little sight – bright, moderately large, fairly rich, about forty odd stars, that form a distinctive oval ring, elongated roughly east-west. The centre contains a knot of four bright, roughly 9 and 10 mag stars, mixed in with a few faint stars. The cluster is immersed in the faint nebulous glow of NGC 6820. It is very difficult to see the nebulosity without an OIII filter – it appears as nothing more than a very slight brightening of the sky, not enough to call a haze. But with the filter, the nebulosity is a faint silky glow, most conspicuous southwest of the cluster’s centre.
NGC 6813 Emission Nebula
RA 19 40 22.4 Dec +27 18 34 Mag – Size 3′
This faint round glow, surrounding a very close roughly mag 13 pair of whitish and bluish stars, certainly needs an OIII filter, which brightens it up considerably. With averted vision I can see a faint shell-like glow around the brighter centre glow. It lies roughly 3′ southeast of a bright white mag 9 star which makes an attractive addition to the view in the eyepiece.
vdB 126 Reflection Nebula
RA 19 26 26.0 Dec +22 43 00 Mag – Size 7′ x 5′
This was my challenging observation of the evening! Not sure why I thought of giving it a try, but I am glad I did. The nebula is exceedingly faint and I could see nothing of it, but the bluey-white mag 8.3 star around which it is wrapped was very pretty.
NGC 6802 Open Cluster
RA 19 30 35 Dec +20 15 42 Mag 8.8 Size 5′
This pretty little open cluster lies at the east end of Al Sufi’s Cluster. About three dozen stars are visible over a widespread haze of unresolved starlight, in an elongated north-south almost oval shape. The cluster lies within a rough trapezoid of 9 – 11 mag stars; the two northern most of the stars both very pretty white stars with widely separated companions.
NGC 6921 Galaxy
RA 20 28 28.8 Dec +25 43 24 Mag 13.4 Size 0.9′x0.2′ SB 11.4
This galaxy lies within a lovely isosceles triangle of mag 11 stars. The galaxy is very faint, exceedingly small, elongated NW-SE, and averted vision reveals a very faintly brighter stellar nucleus. The galaxy MCG +4-48-2, lies 1.5′ to its northeast and despite a long search I think I may have picked it up with averted vision as the tiniest and faintest smudge of light but I couldn’t hold it and couldn’t confirm I wasn’t just seeing what I hoped to see. A very unusual pair of galaxies, being located as they are in the middle of a rich Milky Way field and its unresolved background glow.
NGC 6940 Open Cluster
RA 20 34 26 Dec +28 17 00 Mag 6.3 Size 25′
This is a beautiful, rich open cluster lying in an equally beautiful, rich star field. Even in my 10 x 50 binoculars it shows as a background glow sprinkled with stardust. The cluster is moderately condensed towards the centre, but the majority of its stars are gathered into haphazard knots, chains, and little groupings. Lovely reddish-orange variable star FG Vulpeculae lies near the centre of the cluster. The cluster’s lucida, double star ∑2698, lies off the southwest edge. The peripheries of the cluster stand out well against the starry background, except for its northern edge where its stars blend away into the Milky Way background.
NGC 7052 Galaxy
RA 21 18 33.0 Dec +26 26 49 Mag 12.4 Size 2.5′x1.4′ SB 13.8
This galaxy shows as a moderately bright, oval glow elongated WSW-ENE. Its core is pretty bright and contains a very tiny little glow of a nucleus. A very faint mag 15 star is visible off the north-eastern edge.
Copyright © Susan Young 2017