Where am I?

[Ann]

Sorry, no, TNT! Anyway, Thuban is a blue star, with a B-V index of -0.05. My T is very non-blue. Very!!!

Here's a clue. T is moderately famous, and it is intrinsically bright, likely more so than Thuban, which is quite bright in itself. Some 245 times as bright as the Sun ain't bad for Thuban, which is some 300 light-years away. But T is a lot farther away, and its absolute brightness is uncertain. Clearly it is quite bright, though, but it looks faint because it is so distant. T is an 8th magnitude object, so you need binoculars to see it, A telescope is better still.

When I tell you the correct answer, if no one else can come up with it, you are probably going to say "That's it???".

Ann

[Beyond]

ha-ha, I'm down to T-Rex, and a vague faint something about the Hubble very deep field.

[Ann]

T-Rex is half right, Beyond! It's the Rex part that is wrong!

Ann

[Beyond]

So it's the star Tyrannosaurus Red

[Ann]

Nope! No Tyrannosaurus!

Beyond, think of it like this. You started with T Tauri. Tauri starts with a T (too), which is quite far back in the alphabet. Then you came to T-Rex, and R as in Rex comes before T as in Tauri.

Now you need to to move farther still "up the alphabet" to find the first letter in the word that should come after T!

(Is it TQ, as in TQ Racing? No! Is it TP - Trivial Pursuit? No! Is it TO, as in "TO" do? No! Is it TN, as in Tennessee? No! But I'll stop my walk up the alphabet now, as I'm getting warmer...)

Ann

[Beyond]

Ann, it looks like you've outdone yourself on this one. You're really good at this. Even Margarita only chimed in once. I guess this makes you Queen of the puzzlers.
Going through the alphabet doesn't help me at all. Even if i hit upon the right letter, I'd still be in the cold empty vacuum of space doing this-->

[Ann]

Okay, Beyond. Try a few more letters! I'll tell you when you hit the right one!

Ann

[Beyond]

Ok, i don't go backwards very well, so I'll start with -H-, as in i don't know what the he double hockey sticks I'm doing.

[Ann]

Noooo!!!

What comes after N? I mean, what comes before N? It's M! Exactly!

Okay! What could "M" signify, astronomically speaking? Well, if we are looking for constellations, there's Mensa, Microscopium, Monoceros and Musca. Could T have anything to do with these constellations? Well, let's google!

T Mensae - Google says "What?".

T Microscopii: Google says "Light Curve of T Mic (T Microscopii) from the VSOLJ database (1960)" -uh, I don't think so. Note the year, 1960. (I was unable to open the page and look at the light curve, in any case.)

T Monocerotis: Google says, Yes! T Mon is a bright Cepheid variable, yada, yada. So yes, T Mon could've been the right answer, but it isn't. Anyway, Cepheids aren't red.

T Muscae: Google says, Do you mean T Muscle? Uh, no, I don't. Sorry for asking.

Okay, Beyond, the letter M it ain't! But let's take another step forward. We'll get to... L. Hmmmmmm. Yesssssssss. LLLLLLLLLLL. Maybe... we should take another look at the L?

Ann

[Ann]

Still no takers?

Well, there are many constellations beginning on L. There's Lacerta, Leo, Leo Minor, Lepus, Libra, Lupus, Lynx and Lyra.

Hey - I feel like Tom Lehrer when he's singing about the elements!

Click to play embedded YouTube video.

Well, there aren't quite as many constellations beginning on an L as there are elements beginning on any letter!

But c'm'on now, people! T is in one of the L-constellations I listed above!

Ann

[Moonlady]

T Lyrae, SAO 67087
GSC 2636:1142, HIP 90883, B+36 3168
Spectral: C8
**** Data from Hipparcos Catalog ****
Proper motion (mas/yr): RA = -6.17, Dec = -3.51
Magnitudes Bt: 13.655, Vt: 8.496
Parallax: 1.580 mas, 632.9114 pc
Distance: 2064.28 light-years, 130547576.63 astronomical units
Magnitude: 7.57
RA: 18h 32m 20.076s Dec: +36°59'55.644" (Epoch 2000)
**** Observation Log ****
A very red C* amidst a sea of stars in Lyre. A favorite of summer C* viewing.

[Beyond]

Moonlady, you're just as 'bad' as Ann is.

[Ann]

Click to view full size image

Moonlady wrote:
T Lyrae, SAO 67087

Yes, yes, yes!!!!

Ann

[Ann]

Click to view full size image

T Lyrae.
Photo: bill w, Cloudy Nights Telescope Review

I've never seen T Lyrae myself, but I once saw R Aquilae when it looked just as red as T Lyrae does here. It was pretty incredible.

Ann

[Beyond]

Ok... so what's the-->C*

[Ann]

Well, I guess the C* means "carbon star".

Carbon stars are typically red, although there are carbon stars that are yellow most of the time and then just sort of fade during their "sooty" phase.

Click to view full size image

Carbon stars dump a lot of carbonaceous gunk in their own atmospheres, thereby reddening their own light. It's as if these stars were permanently at a stage of sunset.

Ann

[Moonlady]

Ok... so what's the-->C*

C* means here Carbon star.
Edit: Ann was faster!

I'll post a new question tomorrow, I'm going to leave my laptop at home and meet friends.

[MargaritaMc]

My lack of knowledge was apparent in this question! I didn't know that star 'names' went into 'Latin'letters, so had only searched for 'Tau Lyrae' - not 'T Lyrae'... When nothing came up, I looked elsewhere - and then had to get busy with housework!

Interesting star to learn about - thank you, Ann!
And congratulations, Moonlady!
Margarita

[MargaritaMc]

I've done some homework!

T-Lyrae A Blood Red Carbon Star
http://www.seeintospace.com/charts/charts.html

The first time I saw this star it startled me. It really is red. It's small and you'll have to look carefully to find it but once you do, you'll know it when you see it.

Carbon Stars are a rare type of old, evolved stars that contain more carbon than oxygen. Most stars contain little carbon or oxygen, both of which are formed late in the life of a star after the hydrogen in the star’s core is exhausted and the star begins burning helium. Stars that burn helium grow much larger than their original size and hence are known as red giant or red supergiant stars. Most carbon stars are cool red giant stars.

In most giant stars, the dominant nuclear reaction that fuels the star is the fusion of three helium nuclei to create one carbon nucleus. The carbon atoms participate in other reactions that create oxygen and nitrogen. The normal sequence of reactions produces more oxygen than carbon. In carbon stars, however, some additional or alternative reaction sequence must exist, because these stars contain more carbon than oxygen. Carbon stars also contain unusual ratios of carbon isotopes (carbon atoms with different atomic weights), which is another indication that nuclear reactions other than those of normal stars occur within them.

Something to think about. ALL known life forms are carbon based. No carbon, no life. Yet, carbon is not abundant in the universe. Had a star not gone through its life-cycle and exploded distributing carbon and other elements into our little corner of the Milky Way Galaxy, we wouldn't be here. There would be no solid planets---perhaps only gas giants (like Jupiter) or a star with no attending planets.

What does this mean? It means just because there are billions and billions of stars does not mean they all have sufficient elements nearby to form planets which can support life. In fact, that could be a rather rare event.

It also means that you are literally made of star dust. Had a star not created your carbon, you wouldn't be here.

So let's find T-Lyrae and see a carbon star!  One note...the bigger the scope, the redder this star will look. Why? As you gather more light, you gather more color. But still, this rare beauty will stand out beautifully in the smallest telescopes.

[Ann]

Variable stars get a Latin letter in front of their names to show their variability.

Talking about variable carbon stars, here's another one, R Corona Borealis. This is the rare kind of carbon star that is yellow (make that white, really), but which suddenly "drops out of sight" as it dumps large amounts of soot in its atmosphere all of a sudden.

V Aquilae is variable too, obviously, which you can tell from its "V". It is one of the blood-red carbon stars.

One of my own favorites among the variables is S Monocerotis (S Mon). It's a variable blue O-type star!

One of the most important variable stars are the RR Lyrae stars. They are extremely metal-poor stars at a certain stage of their evolution, and they are used to measure the brightness of and the distance to Milky Way globular clusters.

Arguably the most important variable stars are the Cepheids, named after Delta Cephei. Cepheids have been used to measure the distances to other galaxies.

I don't know why Delta Cephei never got a Latin letter to signal its variability.

Ann

[MargaritaMc]

Thank you for that very helpful information, Ann! More useful reading for me to follow up.
And the picture of S Mon is bee-yootiful.

You wrote
I don't know why Delta Cephei never got a Latin letter to signal its variability.

Well! I was doing my homework JUST as the email notification of your post came to my computer. And what I was reading was this:

http://www.iau.org/public/naming/
THE INTERNATIONAL ASTRONOMICAL UNION
Unfortunately, the Greek alphabet has only 24 letters, and many constellations contain many more stars, even if the naming is restricted to those visible to the naked eye. Johann Bayer then employed low case letters from "a" to "z" and then upper case letters from "A" to "Z" for the stars number 25 to 50 and 51 to 76 in each constellation, respectively...

Variable stars

A notable nomenclature scheme has been developed for variable stars, by Friedrich Wilhelm Argelander in 1862. He proposed to reserve the letters "R" to "Z" for naming the variable stars in each constellation, as Bayer's naming scheme had left these over in each case (and some constellations had a star "Q" in this scheme, e.g. Centaurus, Puppis and Vela).

At that time, the 9 possible names per constellation seemed more than enough, as the number of known variables was small. However, it turned out that it was completely insufficient, and thus the scheme was first extended to two-letter designations, then even to numbers.

Eventually, variables are named as follows: the designation of variables consists of one or two letters and the constellation name (such as U Sagittarii or RR Lyrae) or a number preceded by "V" and the constellation name (e.g., V 1500 Cygni). In each constellation, the first variable discovered is assigned the letter "R" and the genitive of the constellation name, e.g., "R Andromedae" (a long period variable), the second one is "S" (e.g., "S Andromedae" is the supernova which occured in the Andromeda galaxy, M31), and so on up to "Z" for number 9; then the tenth variable is assigned "RR", followed by "RS" etc up to "RZ", "SS" (not "RS"), *etc. up to "SZ", and so on up to "YY", "YZ", "ZZ", and then "AA", "AB", etc to "AZ", "BB" to "BZ", up to "QQ" to "QZ" (where the letter "J" is not used to avoid confusion with the letter "I").

Counting, this scheme provides 334 designations for each constellation, and variables starting from number 335 are designated "V 335", "V 336" etc. Those already assigned a Bayer designation are not given a new name according to this scheme (such as Delta Cephei, Beta Lyrae, Beta Persei, or Omicron Ceti).

Variable stars are classified by types which are then named after one typical representative, e.g., "Mira stars", "RR Lyrae stars", or "Delta Cephei stars" (often called "Cepheids" in deviation from the usual scheme).

This puzzle thread is a fantastic learning tool, I find. And really good fun!

Margarita
* That seems a misprint, but it is what is written on the IAU page.

[bystander]

* That seems a misprint, but it is what is written on the IAU page.

They probably meant "SR" not "RS"

[Ann]

Thanks for that info, Margarita!

Here are a few interesting variable stars with Latin letter designations:

T Pyxidis, a recurring nova which just might go supernova one day.

AE Aurigae, the delightful Flaming Star! (Can't resist showing you this picture as well. You can see AE Aurigae and the nebula it creates, IC 405, on the right, and another emission nebula, IC 410, on the left. In between is a delightful little asterism, the Leaping Minnow, made up of five stars. Can you see that the middle star is bluer than the other blue stars here? The bluest star is IQ Aurigae, the bluest of all stars that are classified as A-type stars!)

V838 Monocerotis (V838 Mon), one of the most remarkable and most enigmatic erupting stars ever seen in the Milky Way. ("V838" means, if I have understood it correctly, the 838th variable star seen in the particular constellation.)

Ann

[Ann]

By the way, I said that T Lyrae is a northerly star, and that it used to be located close to a star that was the North Star before. I frankly can't be sure of that, but it is true that T Lyrae is close to Vega in the sky today. Vega has been the North Star (the Pole Star) before, and it will be so again.

http://en.wikipedia.org/wiki/Vega wrote:
Vega was the northern pole star around 12,000 BCE and will be so again around the year 13,727 when the declination will be +86°14'.

Ann

[MargaritaMc]

Oh, you are an excellent teacher, Ann! What interesting photos and information (I didn't know Vega had ever been the Pole Star!)

Thank you!


The two images of The Flaming Star nebula looked totally different from each other - and I then I realised that they probably were taken from different orientations. Is that correct? (I do wish that it were more common among astrophotographers to give coordinates and the orientation of an image!)

I was intrigued to learn about T Pyxidis, as I didn't know about recurrent novae beforehand, nor had I heard of the constellation Pyxis. So I received TWO valuable lessons in one star!

A video about the expansion of V838 Mon was posted on Asterisk a couple of years ago - before my time, but I found it via Google Advanced ( thanks to bystander showing me how )

The video is at this link:
http://asterisk.apod.com/viewtopic.php? ... 61#p163915

It is mind-blowing!

They probably meant "SR" not "RS"

Yes, that is what I assumed. An easy typo to make. I didn't alter it as it is engrained in me that one does not do that with quotations!

The weather is overcast and cloudy again, today, so I am making good use of enforced indoor-ness by searching the Apod archives...

But, for now, we wait for Moonlady and her promised puzzle.

Margarita