Nextar Identify star Issues
Posted 27 June 2013 - 09:54 PM
I have managed to Align the whole thing with the 2 star method which seem more acurate for me than when I was using the Skyalign.
Not very happy with the Identify though - I thought I would explore a constellation in this case Centaur using the Identify button, but in named stars it only gives a few stars (Centaur has many more than they gave me, think it was 5 only) and the names dont tally with my star charts. So I was forced to manually slew to each star and hope that was indeed the correct star in the constellation.
Am I doing something wrong here, or dont ppl usually explore constellations? (Bear with me Im a neewbie haha)
Posted 28 June 2013 - 11:25 AM
Posted 28 June 2013 - 12:52 PM
I've also had more luck with the auto 2-start alignment. Not sure why but I won't give up trying the SkyAlign feature. As the night goes on, I will re-align occasionally, replacing one of the two original alignment stars.
What magnification are you using to observe constellations? I assume you are using a pretty low power to get a good wide-angle view?
My 130SLT has about 4000 objects in its goto memory. You can add up to 50 user-defined objects, but I'm not sure why you would want to fill that up with dimmer stars from various constellations. Must admit, I haven't used the identify feature much, other than to verify that it works on some of the more obvious stars. Can you give some specific examples of those stars that "don't tally with your star chart?
Posted 28 June 2013 - 01:25 PM
Welcome heartedly to CN and to this Nexstar forum in particular. :bow:
Let me try to give your inquiry my best shot, bearing in mind that I'm not that familiar with Southern Hemisphere stars, constellations, etc.
Thus: as far as I've been able to research throughout today, there does, as you indicate, appear to be only a few stars within the constellation of Centaurus which the hand controller (Identify) feature actually names: these being; as far as I can ascertain:
1) Alpha Centauri.
Not even Rigil Kentaurus is "mentioned" as far as I've been able to ascertain !
I therefore assume this confirms that which you have found ?
Now, I have no idea what star charts you have in your possession but to concentrate on those, (I assumed), listed stars; if you have made a successful alignment, your subsequent GoTos should "pick them up" (according to your wish), in your 6SE's EP. Thus, as a consequence, the "Identity" feature should provide you with appropriate, (albeit), limited information about them.
Equally so, if you go into the "Get RA/Dec" feature of your hand controller, this should give you a stellar position for each star you have targeted, which should tally with your star chart. (This you'd have to confirm).
For those stars outside the hand controller's limited list within Centaurus, (i.e. those unnamed), you will only be able to make your GoTos to them using the GoTo RA./Dec. feature, preferably obtaining co-ordinates from a different source to that of your star charts so that you can cross-reference, on reaching your stellar target, whether it's hand controller co-ordinates match those of your star charts, (or as near to as makes no difference).
Does this perhaps help ?
Posted 28 June 2013 - 01:50 PM
Posted 28 June 2013 - 02:11 PM
Posted 28 June 2013 - 03:46 PM
Regarding alignment methods, I seriously think you'll find that if a "Two Star Align", (preferably an "Auto Two Star Align") works for you, there will be no necessity to attempt "Skyalign-ing" any longer. It is, in any event, merely a "Two Star, (Object), Align" which makes use of a third star (object) just to confirm the positions of the other two.
Rest assured that the "Auto Two Star Align" is indeed the most favoured method of alignment amongst Nexstar owners.
Posted 28 June 2013 - 07:18 PM
After careful alignment the object I am looking for is always in the eyepiece FOV.
I align with 12.5mm Orion Illuminated Plossl Telescope Eyepiece and anything higher like a 20mm will have the object near centered.
This works for video too.
Posted 28 June 2013 - 10:12 PM
Tonight I will try DEC/RA sky permitting!
After more browsing I have since noticed that some smaller constellations don't even have any star listed in the GOTO. I wonder what the 40,000 objects are in the hand device cos if they cant add the stars of the 88 constellations its a bit odd..... Musca and Pavo are two I tried.
The other thing - not really the nextar issue is that the names of the stars used in Nextar only tally for those famous stars. I cant find a whole bunch of star names which is a bit annoying. Im using mainly GoSkyWatch ipad app as my way to see what is in the sky as its got more detail that the skycharts and book I have (which refer to stars usually as zeta centauri or gamma Crux etc. But Tel, as you wrote above I am faced with names like Hadar / kekwan. Can anybody recommend a book/chart/ipad app that uses these hadar/kekwan type names. Cheers all.
Posted 29 June 2013 - 06:13 AM
Perhaps just to put things into perspective, as far as I've been able to research, there are about 150 named stars within the celestial sphere, 90% of which lie in the Northern Hemisphere.
The reason for this is easily understood, as they have either been classically named, (Roman or Greek), or are of Arabic name origin. Hence the dominance of names within a hemisphere known to the Ancients, while the Southern Hemisphere remained largely uncharted for years.
Sure, there is some overlap among those constellations and hence stars which sit on or around the celestial equator but in general, I'm sure you understand the lack of named stars in your hemisphere.
This is not to say, of course, that stars have no identity because for sure they have. They might, for example, be identified by progressive Greek lettering, or within this or that specific numerical catalogue, of which there are many. Each star or object is, in addition of course, identifiable by its position in the sky according to its RA/Dec. co-ordinates.
As to 40,000 objects contained in your Celestron hand controller, (not that you will be able by means to access them all !), these, as you can see, total those stars and objects contained under button 8 of your hand controller entitled "List" and which comprise the following:
SAO (Smithsonian Astrophysical Observatory catalogue). (Vast in number !)
CCD objects. (Astrophotography).
Thus it's not difficult to understand the potential size of the hand controller's data base !
Now, as you probably know, there are various pieces of freeware on the "'net" which will provide you with planetaria: Stellarium and Cartes du Ciel being two examples thereof.
BUT if you want a paper, (i.e. book), version, I'd suggest you look no further than "Norton's Star Atlas and Reference Handbook" edited by Ian Ridpath.
Assuming it's still in print, it will provide you with maps, and practically all the astro-information you require.
Even if it's no longer in print, (and I have a copy of the 19th edition published 1998), I'm sure copies are still on the market. (I bought mine in 2005 via eBay).
True the RA/Dec.co-ordinates would have shifted a little in the elapsed time between then and now due to the Earth's precession, but I still think of it as an invaluable tool.
Does this information help?
Posted 29 June 2013 - 06:40 AM
I recommend you buy it ! Cheap at twice the price for the vast amount of information contained within it !
You won't be disappointed !
Posted 29 June 2013 - 06:51 AM
That's good to know, Ben. Many thanks ! :bow:
I recommend you buy it ! Cheap at twice the price for the vast amount of information contained within it !
You won't be disappointed !
Oh.. I plan on it. I know this is strange, but I love books like these.
Posted 29 June 2013 - 10:19 AM
So does that mean that the more northern constellations feature all the stars that make up their constellation? I hope Celestron have not lets down the southern hemisphere!
To be honest I find all these various catalogues confusing at the moment. Caldwell is C number and Messier is M numbers on my Go skyWatch app. They also have many HIP (what ever that is) stars which a rather boring way to name a star.
Its very Hazy tonight so no DEC/RA till Sunday....
Posted 29 June 2013 - 10:57 AM
Things that we call "the big dipper" are more correctly called asterisms--patterns that are reminescent of something.
Charles Messier was an astronomer and comet hunter in 18th century France. He started cataloging objects which are not comets (because he kept on running into them, and after subsequent observations, said, and I misquote "dang, that's not a comet!"). He started publishing his catalog of "non-comet" objects to aid other comet-hunters. Messier lived in France, so his catalog is northern-hemisphere heavy. It lists approximately 100 of the brightest deep sky non-stellar objects.
The Caldwell catalog is intentionally aimed at amateur astronomers, and does not discriminate northern/southern hemisphere. It is a list of approximately 100 objects, collected by the late Sir Patrick Moore, of brighter/more interesting deep sky objects (nebulas, galaxies, clusters, asterisms, etc.) that Messier did not catalog--nonetheless beautiful objects. Being in Singapore, you (Zymon) should have a spectacular view of Omega Centauri, for example, which is in the Caldwell catalog, but not Messier. Omega Centauri is a huge globular cluster, worthy of your longest FL (lowest magnification) eyepiece. It will put your eye out :-)
HIP is the Hipparchos catalog; NGC is the "New General Catalog", etc.
As Tel states, "named" stars with formal names such as Betelgeuse or Deneb have been named since antiquity. In the west, many of the names come from the Arabic names (Betelgeuse is either shoulder or armpit, depending on your audience :-) because the middle-age and renaissance scholars used arabic documents. All brighter stars (including named stars) have an additional name, based on the constellations in which they reside--so, Vega is also "alpha Lyrae" (alpha==1, Lyrae, belonging to Lyra--brightest star in the Lyra constellation). That's the Bayer name, which is also in the hand control.
Omega Centauri may be found in the NGC catalog as NGC 5139 or Caldwell 80. I don't believe that it is in "named objects" as Omega Centauri.
Go for it, though!
Posted 29 June 2013 - 11:32 AM
If I understand your first question correctly: given any Northern Hemisphere constellation, the chances are that it will have at least one, two, three or maybe even four named stars within it.
For example, Orion, the hunter, lies roughly on the celestial equator and as you know, the four outer stars to its overall shape are named; notwithstanding also, those which constitute his belt.
Thus the outer four stars which make up the basic shape of the constellation are Betelgeuse, Bellatrix, Rigel and Saiph, while Orion's "Sword Belt" is represented by the named bright stars, Alnitak, Alnilam and Mintaka. There are however, and as you are aware, many more unnamed stars within this prominent constellation.
But for the reasons I explained, I don't think Celestron has "sold its Southern Hemisphere customers short" on named stars etc., it's merely that the Ancients were more prolific with their naming !
I must admit that I wasn't at all clear on what you meant by your "Go Skywatch" apparatus ?? Are you just saying that you also have a "Skywatcher" 'scope in addition to your Celestron ? (You don't incidentally mention anywhere which Celestron you have or indeed, which other 'scopes you may own).
If this so, each hand controller be it Celestron, Meade or Skywatcher have their own individual features.
As to HIP numbers; these represent stars logged in the Hipparcos catalogue which was a European Space Agency satellite mission, launched in 1989 to gather star data. As far as I'm aware, data was gathered on as many as 118,000+ stars which gives you an idea of the vastness of the undertaking and the number of unnamed stars "out there" !
Does this help answer your questions ?
Posted 29 June 2013 - 10:35 PM
TEL - I have been using an ipad app called GoSkyWatch. Its what got me started in observing stars quite a while back, I find it useful to point and get an idea of where the constellations are. But since I got the Nextar 8SE I have grown exasperated with the star naming between the nextar/ipad app/my DK stars and planet book.
I probably need a better app or better book/altas that gives multiple names so will not get stuck when I see Hadar on my GOTO and Beta centouri in my book and ohh nooo -Agena in my ipad app. Frustrating!
Posted 30 June 2013 - 05:22 AM
In many cases, but by no means all, you should find that if a star is named; that particular name will be displayed whatever the display media, possibly alongside its Greek lettered identity within its constellation. For example, the name Vega might well be accompanied by its alternative name of alpha Lyrae. It is however unlikely that any further catalogued nomenclature would be used over and above this. In other words, it would be, for example, unusual to see additional reference to, say, its HIP identification.
Unfortunately though, in referring to my copy of Norton's atlas, there does seem to be a singular lack, (as stated earlier), of named stars in the Southern Hemisphere, whereupon my atlas identifies them by their Greek letter nomenclature only.
Regarding Hadar specifically, it just so happens that you have chosen a star with two names. In addition to being known as beta Centauri, Hadar and Agena are apparently one and the same and represents one third of a close triple star system.
Posted 01 July 2013 - 09:57 AM
Its was the clearest night since I got the telescope tonight. Used the DEC/RA to follow the stars of different constellations. Pretty good, although it usually never locks onto the star when it GoesTo. Have to slew a little bit, but then the very bright star hoaves into view its great. Shame I don't have any form of magnification as let.