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At the Top of the Sky: Alpha (α) and Eta (η) Cassiopeiae; 59 Andromedae

A week ago at this time of night (about 11 PM), the temperature stood at a very warm and dry eighty-two degrees, but tonight it’s a comfortably cool fifty-three.  Fall is definitely hovering in the air, and the autumn constellations are now beginning to take over the eastern sky by midnight.  The cool, crisp temperatures almost have me convinced it’s September already.

Six inch f/10 refractor captured taking a break in the house. The scope on top is a 60mm f/15 using a Carton lens. Click on the image for a larger view!

Tonight, in addition to my usual four-legged companion keeping me company at my feet, there is a waxing slice of moon halfway on the way to being full looking over my right shoulder as I begin to explore the Cassiopeia area.  I can use the moonlight tonight because I’m wrestling with a long six inch f/10 refractor on a large non-computerized equatorial mount.  My navigation tools are two pairs of eyes (my dog has the other pair), a Telrad, and a 60mm f/15 refractor mounted on top of the six inch.

From my observing area, the northern sky is blocked by several large fir trees, which means Cassiopeia has to be close to it’s highest point in the sky before it comes into view.  So at midnight that means it’s distinctive “W” formation is standing almost on edge as I face toward the north.  As I look up at the constellation, Beta (β) stands highest in the sky, with Alpha (α)and Eta (η) arrayed underneath it.

Alpha (α) and Eta (η) Cassiopeiae are at the top left on this chart, 59 Andromedae is at the lower center. For a larger view, click on the chart. (Screen image from Stellarium with additional labels added)

Splitting Tools: Both Eta (η) Cass and 59 Andromedae are great 60mm doubles, and the secondary of Alpha (α) Cass is also visible in a 60mm provided you look closely.   Eta (η) especially is a beautiful sight in a 60mm scope, as can be seen in the sketch below, which was done with a 60mm refractor.

Alpha (α) Cassiopeiae  (Schedir)  (H V 18)  (h 1993)
HIP: 3179    SAO: 21609
RA: 0h 40.5m   Dec: +56° 32′
Magnitudes: 2.4, 9.0
Separation:   71.2″
Position Angle: 281°   (WDS 2010)
Distance: 228.5 Light Years
Spectral Classification: K0
Status:  Optical pair

    Look closely to see the 9.0 magnitude secondary! (East & west reversed to match the refractor view, click for a larger version)

Look closely to see the 9.0 magnitude secondary! (East & west reversed to match the refractor view, click for a larger version)

Alpha (α) Cass, or Schedir, is a beautiful sight in the six inch scope.  The primary is a deep yellow, and the much fainter secondary is just a pinpoint of light well separated from it at 76x.  In the 60mm scope at 54x, I don’t see the secondary at all until I glance off to one side of the primary, and then it pops into view over on the other side.  There is a difference of 6.6 magnitudes between the two stars, so the secondary tends to be lost in the glare of the primary, and tonight there is a bit of moisture in the air which is also being illuminated by the glare.  With some perseverance, I find I can pick out the secondary with direct vision in the 60mm.  But not for very long, though – it has a tendency to disappear within a few seconds.  The Haas book notes that other observers have described the secondary as “purple”, as well as “pale garnet.”  Haas describes it as almond brown.  BROWN???? Granted, star colors can be a very subjective thing, but I can’t say I’ve ever seen a star that comes anywhere close to brown!   In that glare, all I can say is the secondary is a bright pinpoint of pale white light.   I’ll keep an eye out for brown dwarfs, though.

Eta (η) Cassiopeiae  (Σ 60)  (H III 3 — AB only)    HIP: 3821    SAO: 21732
RA: 00h 49.1m   Dec: +57° 49′
Magnitudes    AB: 3.5, 7.4     AE: 3.5, 10.2    AH: 3.5, 8.4
Separation     AB: 13.3″         AE: 79.3″           AH: 684.7″
Position Angle   AB: 322° (WDS 2012)   AE: 125° (WDS 2011)   AH: 355° (WDS 2000)
Distance: 19.4 Light Years
Spectral Classification: G0, K7 (Kaler) or MO (WDS)
Status: AB is physical, orbital chart and data can be seen here

The luscious gold and orange of Eta (η) is one of the most stunning sights in the sky! (East & west reversed again, click to enlarge)

The luscious gold and orange of Eta (η) is one of the most stunning sights in the sky! (East & west reversed again, click to enlarge)

Eta (η) is another pretty sight in the six inch.  The primary is a deep yellow-gold, and the secondary is a small orange-white dot standing out near it at 76x.  In this case, I think I prefer the view in the 60mm scope because the two stars are closer together.  But I linger over the sight of this pair in both scopes for about twenty minutes before moving on.   After all, I’m not in a hurry — the cool air is invigorating, the moonlight is splendid, the rumble of the ocean in the background is soothing — and the view in both scopes of these two white stars silhouetted against the black sky is hard to give up!

59 Andromedae  (Σ 222)  (H IV 129)       HIP: 10176    SAO: 55331
RA: 2h 10.9m   Dec: +39° 02′
Magntiudes:  6.1, 6.7
Separation:   16.6″
Position Angle:  36°  (WDS 2011)
Distance: 263 LY
Spectral Classification: B9, A1

Before I quit for the night, I move the scope over to Andromeda to get a look at Almach, which Greg has written a very nice description of here.  After being awed by it’s deep gold and blue, I check the Haas book to see what else is in the vicinity and come up with 59 Andromedae, which lies about halfway between Almach and Beta (β) Trianguli.  I navigate to it via the old naked eye trick by picking out 58 Andromedae, as shown in the map, and then I’m barely able to detect the presence of 59 just to the north of it.  Even at it’s dimmest setting, though, the Telrad tends to blot it out, so I aim into the general vicinity, peer into the eyepiece, and find two closely spaced white stars of similar brightness staring back at me.  At 76x in the six inch, the twin white globes almost look as if they’ve been painted onto a black background sky.  But again, I find I prefer the view in the 60mm scope simply because the two stars are closer together.  And once more, Haas is poetic in her description of the colors: “pearly white and peach white.”

These observations were made just after midnight on the cool and crisp morning of August 20th, 2010, with a cup of tea for me and a Milk Bone for Astro Dog Klaus.

“Woof!”

(WDS data updated 4/14/2013)

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One Response

  1. Brown..? Nope, I’m with you John – never saw any brown stars.

    I enjoy reading your articles.

    Russ

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