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Gamma (γ) Ceti, Better Known as Kaffaljidhma

When you think about it, it’s really not too surprising that a star in the constellation Cetus should sport a whale of name.  🙄

But what, you ask, might that name mean?

How about “Part of a Hand”?   That refers to the circlet of stars that outlines the whale’s head, which at one time was considered to be a hand of outstretched fingers.   The name has also been used as a designation for Alpha (α ) Ceti, which now goes by the more easily pronounced moniker of Menkar — considerably less tongue-twisting than Kaffaljidhma at least.  And as Jim Kaler points out, there’s a longer version of the name, too:  Al Kaff al Jidmah, which gets translated as “the cut-short hand” in some internet sources (such as Wikipedia), or as “the maimed hand” by Admiral Smyth (p. 68 of The Bedford Catalog).    Beware — there may well be a lesson there with regard to breaking up a long word into a string of smaller words.

If it was up to me, however, I would be tempted to call it the Devil Star, because my experience has been it’s a devil of a star to split.  That’s primarily due to it being located far enough south in my ocean influenced skies to be bedeviled by poor seeing and murk-ifying oceanic vapors.  I’ve turned a telescope to Gamma (γ) on numerous occasions, and have always been met by a single shimmering star that refuses to surrender the first hint of duplicity.  More than once I’ve given up that tusk-infested tussle and taken my chances on the equally elusive spiral beauty of M77 and it’s illustrious companion, NGC 1055, and always with better luck.

Neil English recently wrote about his experience with Gamma (γ), and wasn’t having any more luck with it than I’ve had – until he decided to outsmart it by waiting for it to stride across the celestial meridian.  It worked for him, so I gave it a try in hopes it would prove to be the celestial secret to prying Kaffaljidhma’s fingers far enough apart to catch sight of the secondary.

 Looking for all the world like a whale with a small head and a big body -- which is generally the way whales look -- Cetus can be found in the fall swimming in Eridanus, south of Taurus and Pisces.   Kaffaljidhma, aka Gamma (γ) Ceti is at the base of the circlet that outlines the whale's head.   (Stellarium screen image with labels added, click for a larger view).

Looking for all the world like a whale with a small head and a big body — which is generally the way whales look (although that long neck is a bit odd) — Cetus can be found in the fall swimming near Eridanus’s celestial waters, and to the south of Taurus and Pisces. Kaffaljidhma, aka Gamma (γ) Ceti, is at the base of the circlet that outlines the whale’s head. (Stellarium screen image with labels added, click for a larger view).

Gamma (γ) Ceti   (Σ 299)   (Kaffaljidhma)
HIP: 12706  SAO: 110707
.                   Magnitudes        Separation           Position Angle          WDS
STF299     AB: 3.5,   6.2                2.30”                      298°                   2008
ADL 124   AC: 3.5, 10.2           843.10”                      306°                   2000
Distance: 82 Light Years
Spectral Classification:  “A” is A3, “B” is F3, and “C” is K5

It now seems like a whisper from the remote past, but it was a mere three months ago that I set sail for Gamma (γ) Ceti once more, back in that barely remembered era of sparkling clear nights which seem like such a nebulous dream now, and have me crying out many a rainy morning from my tortured 4-AM sleep:  “It’s a split!

Five days after sailing so innocently into those early October skies, the November rains arrived prematurely (October 15th at 11:28 AM to be exact) – and most of the following three months were drowned in a deluge of 49.75 inches of rain.   I’m looking at real estate now that is worry-free of runoff concerns and doesn’t require a boat dock beside the garage.

But prior to that, my only major worry was whether I could penetrate that whale of an obscuring cloud which seemed to surround Gamma (γ) Ceti.   I’ve since come to the conclusion that part of the reason – maybe the main reason – for the difficulty I’ve had with this star is the dim nature of the entire constellation it calls home.   Cetus is not the brightest arbitrary conglomeration of stars in the autumn skies, which means it’s easy to ignore, which I’ve done repeatedly.   I’ve almost conjured up enough interest a couple of times to begin a serious exploration of the Cetian confines, but more thrilling sights – like Lacerta – have always whisked me away.  So I suspect Cetus thinks I don’t care for it, and has decided to be difficult.

C before I found a finder for it.

C before I found a finder for it. (Click for a larger view).

Difficult it certainly was on that October 10th evening when I returned to it for another dubious attempt at detecting Gamma’s duplicity.   I was almost conditioned to expect failure, which is not the best state of mind in which to attempt a difficult feat of stellar legerdemain.   Even when I made my six inch f/8 Celestron refractor aware of what we were going to attempt, it looked at me as if to say: “Not THIS again – don’t you ever learn?”  I tried, but I just couldn’t look it straight in the lens.

And sure enough, on first approach, I found myself confronted with that same old single yellow-white stellar orb of sparkling starlight.   I knew it well.   As I attempt to recall that distant night now, it seems  the six inch refractor was armed with a 12mm Radian (100x) for that first view.   I remember thinking (always a dangerous thing to do in the dark) ——-  hmmmmm, what should I try next ——-  when I heard a metallic voice echoing and rumbling in the dark depths of C’s starlight saturated aluminum cylinder:

“Look, why don’t you give up the thinking stuff, go in the house and get that little 9mm UO Ortho you rarely let out of the box, bring it out here, and give it to me.  It’s about time we terminated this torture.”

Now I’ve never been one of those people who allows a talking telescope to tell them what to do, but I could see some merit in the idea.  So I obediently followed C’s instructions, dug the diminutive chrome devil out of its faded green box, removed it from the plastic wrapper, pulled off the end caps, tossed it up in the air and watched it do two somersaults in celebration of it’s out-of-the-box freedom, caught it, went back outside, and handed it to C.

“Merci,” it said.  “Now how ’bout standing back for a minute and give me some room to work.”

I watched as the focuser twitched a couple of times, then crept its way forward toward the front of the tube, twitched a couple of more times, slipped backwards a few infinitesimal millimeters, twitched again —– and then I heard a grunt, followed by that hollow rumbling metallic voice:

“Have a peek.”

I did.

And heavens to Hamal if that secondary wasn’t lookin’ right back at me.

The primary is a very bright white with just a tinge of yellow. There might have been just the slightest taste of blue in the secondary, but it was so firmly attached to its parent it was hard to distinguish a separate color. There’s a distant third component just over 14 arc minutes beyond the secondary (which puts it outside of this field of view), but I didn’t know about it at the time I made this sketch. At that distance, and with a magnitude of 10.2, it should be a whole lot easier to see than the secondary. (East & west reversed to match the refractor view, click for a larger version).

The primary is a very bright white with just a tinge of yellow. There might have been just the slightest taste of blue in the secondary, but it was so firmly attached to its parent it was hard to distinguish a separate color. There’s a distant third component just over 14 arc minutes beyond the secondary (which puts it outside of this field of view), but I didn’t know about it at the time I made this sketch. At that distance, and with a magnitude of 10.2, it should be a whole lot easier to see than the secondary. (East & west reversed to match the refractor view, click for a larger version).

It was welded to the primary so tightly I quickly developed doubts about prying it loose.  I had this fleeting vision of forcing the two stars apart and suddenly seeing the secondary dart off into interstellar space, never to be seen again.  That would have been hard to live with.

“Whadda ya think, C?”, I said.

Don’t.

So I left it where it was, content to stare at it for a full fifteen minutes.   After so many failures, it was quite a sight.  Even though the two stars were attached, the circular orb of the secondary was very distinct.  I allowed that insistent urge to pry it loose to whither and run off of me, much like the rain would do five days later.  But it sure was tempting.

This is another one of those stars that mystifies the observer with a variety of colors.   The spectral classifications of the primary and the secondary lead you to expect  blue and white light only, but a flash of yellow consistently creeps into the view.  Haas describes them as a “whitish banana yellow and a pale opal green” – although I sure didn’t see the green  —  and Admiral Smyth saw “pale yellow” in the primary and “lucid blue” in the secondary.  Maybe if I had pried the secondary loose, the blue would have been more obvious — but I just could never bring myself to do it.

After my fifteen minutes or so of Cetacean serenity, I uncoiled from my seated position, stretched my cramped frame back into its usual stretched-out state, walked around the deck a few times, chanted Kaffaljidhma very fast until my tongue tripped over the syllables – which was almost immediately – and then I remembered I hadn’t thanked that long black aluminum six inch refractor for its help.

I walked back over to it, reached down, and patted C on the rear of its tube, just above the focuser.   It trembled a bit, then relaxed, and sighed, “Ahhhh  ——  love it when you do that.

.

Clear Skies.     :mrgreen:

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8 Responses

  1. Hi John, tonight I had a chance to observe Kaffalijdhma
    in Cetus. Using a 150mm reflector at 165x I thought I could
    see the companion just off the west side of the primary when
    I moved to 275x the companion was clearly seen well seperated
    from the primary. To me the primary looked white and the
    companion had a trace of yellow which seemed to come and go.
    It is a beautiful double but trickey. tonight there was a slight mist
    but the seeing was not bad.

    cheers

    Pat.

  2. Hi Pat,

    Tricky is a good description!

    Kaffalijdhma strike me as being a lot harder to split than it should be. Not sure why that is, although I know the seeing at my location is a major part of the problem. With 150mm’s of aperture, regardless of whether it’s a refractor or a reflector, you would expect it to roll over and surrender without a fight — but it just doesn’t happen. I really wonder whether the separation is a bit tighter than the 2.30″ list for it in 2008.

    John

    • Hi John,
      I would have to agree with you as to the separation, after I posted
      the previous comment I went back out to have another look just as
      tricky as before, I then moved to the nearby star Alrescha STF202
      in Pisces. This is another beautiful double which I found to be easier
      than Kaffalijdhma, now the thing is this is a closer double sep. 1.9″
      although slightly less difference in magnitude between the components I would not have thought it would have made it so much
      easier to split. Maybe your right John and Kaffalijdhma is tighter
      than recorded.

      Pat.

      • Good observation, Pat — and as you mentioned, Alrescha is not at all far from Kaffalijdhma, so it’s easy to move back and forth between the two and compare them. Hmmm, if I get a cooperative night, that could be an interesting comparison at a couple of different apertures.

        The current figures in the WDS orbital catalog put the separation for Alrescha at 1.761″ for 2013, and the magnitude difference between the primary and secondary is 1.1; for Kaffalijdhma, the difference is 2.7 magnitudes with a supposed separation of 2.30″. You would think that wider separation — which is very significant in such confining distances — would be enough to offset the closer separation of Alrescha, resulting in a pair that is equal in difficulty.

        But it’s one of those aspects of double stars that makes them so intriguing, and also a good example of how elusive the effort it is to pin down a formula for determining in advance what can be split at a given aperture. On the other hand, if the WDS separation for Kaffalijdhma is incorrect, it’s an entirely different matter.

        Must be the mystery of it all that keeps us coming back again and again. 😉

        John

  3. John , last night cleared about 10.30 pm so I tried to observ
    Alrescha and Kaffalijdhma again but I was to late they had gone
    behind some trees so I moved to Orion and Dawes 5 which split
    well at 275x . To me the primary looked white and secondary off
    white. The mags. are3.56 4.81 seperation 1.8 difference is
    1.31 . to compare I moved to Propus in Gemini, this was a different
    story , I could not say I split it even at 400x I could not be sure
    I was seeing the companion. The mags. for Propus are 3.5 6.1
    seperation is 1.6 ” and the difference in magnitude is 2.63 so
    about twice the difference of Dawes 5, so maybe that extra 1.3
    magnitude difference makes all the difference or would the color
    of the stars make them easier or harder to see. Half the fun as you
    say is in the mystery.

    Pat.

    • Ah yes, Propus! I haven’t had a look at that demon double star since it thrashed me thoroughly last year. That one is TOUGH! I think I’ll ad that to my list. Alrescha, Kaffalijdhma, and Propus — to get a night where all three could be split would be a real treasure.

      Dawes 5 I’m not familiar with at all, so I’ll take a look at it first chance I get. It’s been a very poor winter for star gazing, but I see some hope finally for the first part of the coming week.

      John

  4. John , another double to add to your list 32 Orion, I tried this one
    last night with no luck but tonight it give up the fight at 275x split
    by a hair . This is one of those doubles that I am not sure of the
    colour primary looks white, then there seems to be a trace of blue
    the secondary looks white with a hint of yellow. The magnitudes
    are 4.44 5.75 separation Iam not sure one source says 1.3″
    another says 0.8″ . Looking at it I would the former is more likely.
    Back to that devil of a star Propus I was sure I would split it tonight
    but again I failed, there was a hint of something round about the
    4-5 oclock position but I could not be sure, have to keep trying.
    Just before the clouds rolled in had a quick look at Dawes 5 aka
    Eta Orion nicely split at 275x bright double.

    Pat.

    • I was just doing some research in the WDS and discovered that Dawes 5 is Eta Orionis, which I’ve split several times. That one is surprisingly easy, but that 1.8″ separation and 1.3 magnitude spread makes a big difference, as you mentioned.

      I’ve seen the discussion on CN about 32 ORI — I would love to be able to glimpse the secondary in that one, but at 1.3″ it will require a darn good night.

      I also found a couple of Dawes’ other gems to the southeast of Eta Orionis. Dawes 4 has a 1.1″ separation with a magnitude difference of 2.9, and Dawes 6 has a separation of 0.15″ — and that’s all you need to know about that one! I’m beginning to think he and S.W. Burnham intended to leave a legacy of torture for those who tried to follow in their footsteps!

      John

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