Where am I?

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Moonlady
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Re: Where am I?

Post by Moonlady » Wed May 15, 2013 11:09 pm

So I keep hanging and dangling around till she comes back...to the left...to the right...to the left...to the right...till I reach expert level :D

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Re: Where am I?

Post by Ann » Wed May 15, 2013 11:46 pm

I'd say that the answer is Vela, yes. Vela is a part of the original huge constellation Argo Navis, which was split up into Vela (the sails), Carina (the keel) and Puppis (the stern).

Argo Navis had only one Alpha star, Canopus. Canopus ended up in constellation Carina, so it is now Alpha Carinae. Canopus is the second brightest star in our skies, after Sirius. It can be seen at far right in this (computer-generated?) map of constellation Carina.

(It may be added that Canopus is a star of spectral class F0II. It is quite blue for its spectral class, which can also be seen here and here. It does look non-blue here, however.)

Neither Vela nor Puppis got an Alpha star after they became their own constellations. The brightest star in Vela is the remarkable double star Gamma Velorum, a binary made up of one O-type star and one Wolf-Rayet star. The Wolf-Rayet component is extremely hot, and it is losing a tremendous amount of mass through an incredibly fierce wind. Wolf-Rayet stars are believed to represent a late stage in the evolution of O-type stars, and a supernova may not be far away.

The brightest blue star in this fantastic Rob Gendler skyscape centered on Vela is Gamma Velorum.

The brightest star in Puppis is Zeta Puppis, a hot bright O-type supergiant. Does it look blue here? Yup, it does. It's not quite so blue here, where, on the other hand, it is described as "angry".

Ann
Last edited by Ann on Thu May 16, 2013 12:08 am, edited 1 time in total.
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Re: Where am I?

Post by Beyond » Wed May 15, 2013 11:59 pm

Ah, that's why she said it was 'simple'. But i still wouldn't have gotten it, even if she had used a broken up ship for a clue that said ARGO on the back of it. Oh well, it's a good thing I'm Beyond it all. :lol2:
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Re: Where am I?

Post by MargaritaMc » Thu May 16, 2013 8:18 am

Marvellous detective work - but WRONG!!

You are looking for another sail in the sky, which is actually the First Sail I showed you, but that - lesser known type of sail - is often mistaken for the SECOND sail that I showed you.

If you can recognise the sail in the second clue and look in Google for THAT, you will (I think!) find the name of this older and less common sail! If not - as this probably is difficult for non-sailors! - look up Gaff rig on Wikipedia. The name I'm looking for is listed there.

THEN you will either exclaim 'AH HA! Of course!' and recognise the name of the star/constellation/asterism. Or you can search for that name in an astronomy site.

A third clue: What did Margarita recently 'See In The Sky Last Night'?

Margarita
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Re: Where am I?

Post by Beyond » Thu May 16, 2013 9:56 am

Well... looking up Gaff rig did nothing for me, and you could have seen just about anything last night. so once again, the Whizzy Wheeler is leaving tracks all over me :!: :lol2:
OH, Recently...so you're looking for
one of the 11 stars of corvus?
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Re: Where am I?

Post by Beyond » Thu May 16, 2013 12:10 pm

How about this, open carefully so you don't get hurt :!: -->
Spica's Spanker
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Re: Where am I?

Post by MargaritaMc » Thu May 16, 2013 12:21 pm

Beyond wrote:How about this, open carefully so you don't get hurt :!: -->
Spica's Spanker
HURRAH! HE'S GOT IT - BY JOVE, HE'S GOT IT!

Image
The Stellar Neophyte says
Corvus the Crow and Spica's Spanker
Corvus the Crow, with pointer stars toward Spica. Part of the shape resembles a kind of sail called a spanker, which gives the 4-star asterism the name "Spica's Spanker."
When I saw Corvus for the first time a few days ago the resemblance to a gaff-rigged spanker sail was remarkable. Me? Sailing background? What ever gives you that idea?
http://en.wikipedia.org/wiki/Corvus_(constellation)
Four principal stars, δ, γ, ε, and β Crv, form an asterism known as "the "Spica's Spanker" or "the Sail". γ and δ serve as pointers toward Spica.
The four brightest stars in Corvus are mostly unremarkable. Alpha Corvi, also called Alchiba, is a white-hued star of magnitude 4.0, 40 light-years from Earth. Beta Corvi is a yellow-hued giant star of magnitude 2.7, 140 light-years from Earth. Gamma Corvi, also called Gienah, is the brightest star in Corvus at magnitude 2.6. 165 light-years from Earth, it is a blue-white hued giant star. Its traditional name means "wing". Delta Corvi, traditionally called Algorab, is a double star divisible in small amateur telescopes. The primary is a blue-white hued star of magnitude 2.9, 88 light-years from Earth. The secondary is a purple-tinged star of magnitude 9. Its common name means "the raven".
I was going to post and ask Ann about the ¿PURPLE? tinged star, but decided to make a puzzle of this delightfully named asterism - SO BRILLIANTLY DEDUCED BY BEYOND - before asking
- DO purple stars exist?? HOW??
Margarita
"In those rare moments of total quiet with a dark sky, I again feel the awe that struck me as a child. The feeling is utterly overwhelming as my mind races out across the stars. I feel peaceful and serene."
— Dr Debra M. Elmegreen, Fellow of the AAAS

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Re: Where am I?

Post by MargaritaMc » Thu May 16, 2013 12:33 pm

Image
Just to be able to compare this Spanker with the asterism.

Further info - the Spanker sail is sometimes confused with a Spinnaker - a picture of which was my second clue.
M
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Re: Where am I?

Post by Beyond » Thu May 16, 2013 12:41 pm

Purple star :?: :?: It's probably just a blue star shinning through some red stuff. :mrgreen:
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Re: Where am I?

Post by MargaritaMc » Thu May 16, 2013 12:47 pm

Beyond wrote:Purple star :?: :?: It's probably just a blue star shinning through some red stuff. :mrgreen:
Do you know - that didn't occur to me?! Duh! Thank you - here is your bouquet.
Image
"In those rare moments of total quiet with a dark sky, I again feel the awe that struck me as a child. The feeling is utterly overwhelming as my mind races out across the stars. I feel peaceful and serene."
— Dr Debra M. Elmegreen, Fellow of the AAAS

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Re: Where am I?

Post by Beyond » Thu May 16, 2013 1:21 pm

Well, i don't know if it's scientific, and it probably wouldn't happen too often, but red and blue do make purple, so it would seem that conditions are just right for the star to appear purple to us, here on earth.
Thanks for the flowers, and no bees. That way i don't get a 'buzz' when i sniff them. :mrgreen:
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Re: Where am I?

Post by Ann » Thu May 16, 2013 2:19 pm

MargaritaMc wrote: I was going to post and ask Ann about the ¿PURPLE? tinged star, but decided to make a puzzle of this delightfully named asterism - SO BRILLIANTLY DEDUCED BY BEYOND - before asking
- DO purple stars exist?? HOW??
Margarita
No, Margarita, purple stars do not exist.

The star that was described as purple is the fainter component of the binary star Delta Corvi. The brighter component of Delta Corvi is described by my software as being of spectral class B9.5V, and its Johnson B-V index is given as -0.012. The fact that Delta Corvi A has a negative B-V index is certain proof that it is blue, which is normal for B-type stars, even for late B-type stars like Delta Corvi.

But the fainter component is supposed to be purple. How is that possible? The answer is that it isn't.
Robert Burnham, Jr., wrote about Delta Corvi in Burnham's Celestial Handbook, volume two:

Name - ALGORAB. Mag. 2.95; spectrum A0 V or B9.5 V. Position 12273s1614. Delta Corvi is an easy double star for the small telescope, first observed by J. Herschel and J. South in 1823. There has been no change in either the separation or the PA of the pair in the last 140 years, although the physical association is proven by the common proper motion of 0.26" per year in PA 235 degrees. Most observing lists have called the colors "yellowish and pale lilac"; occasionally "white and orange". The small star, magnitude 8.4, has a spectral type of dK2 and an actual luminosity of about half that of the Sun.
The spectral class of the fainter star is described by Burnham as dK2, by which he means that this is a main sequence K-type star. Such stars are never purple. On the contrary, they are yellow, yellower than the Sun. So why would anyone think that this one might be purple?

I think it is obvious that the first influential observers of double stars had a great impact on the way these double stars were perceived, because they described the colors of the double stars they observed in a way that seemed convincing and inspiring to others. One such early observer was William Henry Smyth. You should read the entire wikipedia entry about him, because he seems like a fascinating man. Just consider the fate of his wives and daughters - they either died early and childless, or else they procreated as if they were trying to populate the Earth all by themselves!

But now we should discuss him as an observer of double stars.
http://en.wikipedia.org/wiki/William_He ... other_work wrote:
The first volume of this work was on general astronomy, but the second volume became known as the Bedford Catalogue[5] and contained Smyth's observations of 1,604 double stars and nebulae. It served as a standard reference work for many years afterward; no astronomer had previously made as extensive a catalogue of dim objects such as this. It was reprinted in 1986, and in the Foreword to that edition George Lovi (astronomer and writer)[6] writes, "What makes it so special is that it is the first true celestial Baedeker and not just another "cold" catalogue of mere numbers and data. Like the original Baedeker travel guidebooks of the last century, this work is full of colorful commentary on the highlights of the heavenly scene and heavily influenced several subsequent works of its type, even to the present day. ... It is in the descriptive material that Smyth is a delight. He not only describes what the user of a small telescope will see, but also includes much fascinating astronomical, mythological, and historical lore. Many of these descriptions are especially valuable for the novice and user of small telescopes of a size similar to Smyth's."
Burnham of Burnham's Celestial Handbook often quoted Admiral Smyth's description of the colors of various binaries. When I first read about these color descriptions in Burnham's Celestial Handbook, I often thought the colors described sounded totally improbable. I didn't believe in his colors at all. So where did he get them from?

Well, frankly, I think he imagined them! I think he imagined them in the same way as Percival Lowell imagined that he saw canals on Mars. I think Admiral Smyth imagined at least some of the colors he reported.

Very often, Admiral Smyth reported seeing the brighter component of a double star as yellowish and the fainter component as bluish. I think you will agree with me that purple is a bluish color rather than a yellowish one. It is quite possible that his eyes worked like that, so that he almost always saw the brighter component as yellower than the fainter one.

There are, of course, several double stars where the primary component is much yellower than the secondary one. Albireo is the archetypal example, but there is also Gamma Andromedae and several others, for example 30 and 31 Cygni.

I have written here at Starship Asterisk* on another occasion that for a long time, blue stars were considered impossible. Stars were regarded as either white, yellow, orange or red. With the invention of the telescope, blue stars were discovered, particularly the fainter component of Albireo, of course.

David Malin wrote in his book, A View of the Universe:
After centuries of sky-watching with the unaided eye, no-one had ever described the stars as other than white, yellow or reddish-orange. Some blue stars were known from telescope observations, but they were always members of strongly coloured pairs of visual double stars and were therefore a curiosity.
So according to David Malin, blue stars were long believed to exist only in visual double stars. If blue color in stars was believed to exist only in double stars, then this blue color could be considered "a miracle". And if it was the the binary nature of some stars that conferred this wondrous blue color onto one of the components in a binary, why shouldn't there be other amazing colors in double stars, too? Why not lilac? Why not green?

I think Admiral Smyth and a few other pioneers like him mostly noted color in pairs like Albireo, where the primary is yellow and the secondary is blue. I think that because of this, they always expected this pattern to hold. So when they observed a star like Delta Corvi, where the primary is blue-white and the secondary yellowish, their brains "adjusted" the colors of the stars so that the primary appeared to be yellower than it really is and the secondary bluer. Remember that the primary of Delta Corvi is a blue-white star of spectral class B9.5V, while the secondary is a yellowish K-type dwarf. Yet someone, likely Admiral Smyth, described the primary as yellowish and the secondary as pale lilac. But others, far more correctly, described the pair as white and orange!

So to summarize, Margarita, there are no purple stars. But some authorities are incredibly influential, and if they said that they saw purple stars, then so will many of their followers. Because sometimes colors are all in your mind.

Ann
Last edited by Ann on Fri May 17, 2013 12:45 am, edited 1 time in total.
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Re: Where am I?

Post by Beyond » Thu May 16, 2013 2:34 pm

MargaritaMc wrote:
Beyond wrote:Purple star :?: :?: It's probably just a blue star shinning through some red stuff. :mrgreen:
Do you know - that didn't occur to me?! Duh! Thank you - here is your bouquet.
Image
Commodore Ann, color commentator of the Asterisk*, has spoken about the purple star.
So now i have to return your bouquet. Please give it to Admiral Smyth. Make sure you include lotsa bees. :yes: :mrgreen: :lol2:
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Re: Where am I?

Post by MargaritaMc » Thu May 16, 2013 2:38 pm

ImageThank you, Colour Commentator! I KNEW that you would come to the rescue!

But, would Beyond's idea work, of seeing a blue star through some red emission, and this have given a starter to the idea that lilac stars exist?

I will read about the Admiral straight away!
What a fascinating/appalling person he sounds...
Margarita
"In those rare moments of total quiet with a dark sky, I again feel the awe that struck me as a child. The feeling is utterly overwhelming as my mind races out across the stars. I feel peaceful and serene."
— Dr Debra M. Elmegreen, Fellow of the AAAS

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Re: Where am I?

Post by MargaritaMc » Thu May 16, 2013 2:40 pm

Beyond - the flowers were for getting SPICA'S SPANKER!
I'm sure the Admiral would be impressed. And - as he is clearly colour blind - he wouldn't enjoy the flowers.
Margarita
"In those rare moments of total quiet with a dark sky, I again feel the awe that struck me as a child. The feeling is utterly overwhelming as my mind races out across the stars. I feel peaceful and serene."
— Dr Debra M. Elmegreen, Fellow of the AAAS

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Re: Where am I?

Post by Beyond » Thu May 16, 2013 2:54 pm

MargaritaMc wrote:Beyond - the flowers were for getting SPICA'S SPANKER!
I'm sure the Admiral would be impressed. And - as he is clearly colour blind - he wouldn't enjoy the flowers.
Margarita
Ok, i get to keep them then. Sniff, sniff, sn-a-a-a-a-choo! Things get dusty fast around my place. I don't have dust bunnies, i have dust-ephants. :lol2:
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Re: Where am I?

Post by MargaritaMc » Thu May 16, 2013 2:55 pm

As President of the Astronomical Club, he was always genial & courteous, ever keeping things in happy order, and by his ready wit and flow of humour compelling the maintenance of good fellowship. He used to fill his pockets with new half-pennies to distribute to any children he met in his daily walks. Whatever he did, he did it with his might. RASoc Obituary.
From the Wikipedia link about Admiral Smyth.

I am open-mouthed with admiration!
And delighted to discover that he was grandfather to Robert Baden-Powell, the founder of the Scouting movement. (My years in the Girl Guides - as Girl Scouts are called in Britain - were hugely enjoyable and, old-fashioned word - 'edifying'.)

Margarita
"In those rare moments of total quiet with a dark sky, I again feel the awe that struck me as a child. The feeling is utterly overwhelming as my mind races out across the stars. I feel peaceful and serene."
— Dr Debra M. Elmegreen, Fellow of the AAAS

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Re: Where am I?

Post by Ann » Thu May 16, 2013 4:31 pm

Margarita wrote:
But, would Beyond's idea work, of seeing a blue star through some red emission, and this have given a starter to the idea that lilac stars exist?
I'd say no, Margarita. First of all, human eyes really can't detect the red color of emission nebulae, because their wavelength is "too far into the red part of the visual spectrum", where the sensitivity of our eyes is low. If a blue star sits in a lot of nebulosity, it might be "reddened" so that it looks less blue than it really is. It may well look white, maybe even yellowish, as is the case of heavily reddened Rho Ophiuchi, whose blue light is spread out around it in a magnificent blue reflection nebula. The star - or stars, actually - look far yellower than they are, after having "lost" so much of their blue light to the reflection nebula. But they certainly don't look purple.

Another thing that we don't often think about is that most nebulae are really faint, whereas the stars are brilliant point sources. I remember when one of the first Hubble astronomers described his dismay after he had tried to photograph a red emission nebula in the Large Magellanic Cloud, using Huble. He had forgotten to "turn down the light of the stars" and "turn up the nebula". All he saw in that first photograph was a few small but bright blue point sources and a lot of black sky!

So, no, I don't think a nebula can make a blue star look purple, not to our human eyes, anyway.

Ann

P.S. Beyond, thanks so very much for those flowers! But Margarita is right, you must keep them. Spica's spanker - who would'a known? Not me, that's for sure! I may be a commodore, but I sure ain't no sailor! :shock:

Ann
Last edited by Ann on Thu May 16, 2013 11:44 pm, edited 1 time in total.
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Re: Where am I?

Post by Beyond » Thu May 16, 2013 4:56 pm

I didn't know about the spanker either. After discovering the Corvus sail, i think (if i remember correctly) Wikipedia gives info about what kind of sail it is, and that it is also called a 'spanker', and because Spica is the top of the mast, it's called Spica's Spanker. I didn't know before that Spica was the top of the mast. Sometimes ya just gotta have a little help from the 'salt' of the sea, no matter where it rolls in from. :yes: :lol2:
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Re: Where am I?

Post by MargaritaMc » Thu May 16, 2013 7:02 pm

Beyond said
Sometimes ya just gotta have a little help from the 'salt' of the sea, no matter where it rolls in from. :yes: :lol2:
I've just posted some salt of the sea
I hope you enjoy it!
Margarita
"In those rare moments of total quiet with a dark sky, I again feel the awe that struck me as a child. The feeling is utterly overwhelming as my mind races out across the stars. I feel peaceful and serene."
— Dr Debra M. Elmegreen, Fellow of the AAAS

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Re: Where am I?

Post by MargaritaMc » Sun May 19, 2013 8:26 pm

This just occurred to me
devil_chortling.jpg
And even I feel that it is a bit of a tricky puzzle!

It is simply to

find an astronomical connection with the Battle of Gataskogen...

But Ann might get it straight away!

Margarita
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— Dr Debra M. Elmegreen, Fellow of the AAAS

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Re: Where am I?

Post by Beyond » Sun May 19, 2013 10:56 pm

Seeing as how i know nothing of the battle of the street forest, I'm staying out of this one!! Norwegian doesn't translate so good.
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Re: Where am I?

Post by Ann » Sun May 19, 2013 11:42 pm

Honestly, Margarita, I had never heard of the battle of Gataskogen, where this man was captured. Must have slept during my history lessons.

But now that I've googled it, I can see that this battle took place in 1365, so.... NGC 1365?

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Re: Where am I?

Post by Beyond » Sun May 19, 2013 11:49 pm

Ann wrote:Honestly, Margarita, I had never heard of the battle of Gataskogen, where this man was captured. Must have slept during my history lessons.

But now that I've googled it, I can see that this battle took place in 1365, so.... NGC 1365?

Ann
That's a neat picture, Ann. The bar has a very full puffy look to it, that i don't recall seeing anywhere else before. Ya think it's pregnant :?: :?: :mrgreen:
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Re: Where am I?

Post by Ann » Sun May 19, 2013 11:56 pm

Who knows? They say it's got a black hole in its tummy - maybe it's ready to burst?

Ann
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