How to find max. elevation of Saturn nebula?

[pandoraefretum]

Hi Group,

I was wondering with Sky Safari 6 Pro, how can I find the best time to view the Saturn nebula ?
I need it to be as high as possible in the sky... so I need to know the culmination of Aquarius, which is October, I think.

I live 52 deg N, obviously I have my location entered into Sky Safari, but I need to know how to find the maximum elevation of the Saturn nebula.
I thought it would be simple, but I can't find a definite procedure... I am just able to fiddle things with the Time buttons, and get a rough idea.

Thx, bye for now, Roland

[johninderby]

According to Luminos it’s about three in the morning.

 

[pandoraefretum]

Thanks, but I am specifically trying to get this result in Sky Safari 6 Pro...

Thx anyway... 

[david_taurus83]

Not quite sure what info your looking for? Select the target and press centre on object. Then set the time to minutes and fast forward or reverse until it is due south. It will never rise higher than at due south at our latitude for the next few millennia at least.

Edited July 5, 2019 by david_taurus83

[Martin Meredith]

You can compute the approx max elevation of any object if you know your latitude and its declination, using the formula:

90 - your latitude + object's declination

For instance, the Saturn Nebula has a declination of about -11 degrees, and you are at 52N, so the max elevation is approximately 90 - 52 - 11 = 27

I live near 43N so for me it is around 36.

Of course, it is then a case of deciding when it is astronomical nighttime when the object reaches maximum elevation....

See: http://astrodictionary.org.uk/altitude/

cheers

Martin

 

[Stu]

6 hours ago, pandoraefretum said:

Hi Group,

I was wondering with Sky Safari 6 Pro, how can I find the best time to view the Saturn nebula ?
I need it to be as high as possible in the sky... so I need to know the culmination of Aquarius, which is October, I think.

I live 52 deg N, obviously I have my location entered into Sky Safari, but I need to know how to find the maximum elevation of the Saturn nebula.
I thought it would be simple, but I can't find a definite procedure... I am just able to fiddle things with the Time buttons, and get a rough idea.

Thx, bye for now, Roland

It's very easy Roland. Select the object, in your case the Saturn Nebula, then go to the information tab. In there it lists the time that it transits (aswell as when it rises and sets), for tonight it is 3.11am for me. Additionally, if you tap the little clock by the side of it, it will centre the object and take you to that exact time.

Simples

[pandoraefretum]

Thx Supernova, but my question is slightly different.
I know how to find the transit time, and centre it for any given moment....
but what I want to know is on what day will it be at its highest for the whole year... ie. culmination

Any help appreciated, Roland

 

[Martin Meredith]

It culminates at the same elevation every day. However, at times it is daylight when it culminates and at other times it is astronomically dark. 

[david_taurus83]

It will never get higher in our lifetime. Like I said, it will be a few thousand years. 2.5k until its above the celestial equator. Polaris wont even be the north star by then!

 

 

[Stu]

5 hours ago, pandoraefretum said:

Thx Supernova, but my question is slightly different.
I know how to find the transit time, and centre it for any given moment....
but what I want to know is on what day will it be at its highest for the whole year... ie. culmination

Any help appreciated, Roland

 

Just remembered there is a function called Graph Object which you find in the Selection tab. This might enable you to work it out, you can shrink or grow the timeline to see when it is best placed.

[lenscap]

As shown above the Saturn Nebula transits at about 3am at the moment. Not dark enough.

Say you want to observe it at transit at about midnight when it is as dark as possible, 3 hours earlier.

3 hours earth rotation is 45 degrees so you need the earth to move  45 degrees around its orbit to achieve this. Since the earth moves about 1 degree per day this will happen in 45 days which is 20th August.

To demonstrate plug this date & time into SS6.

[Stu]

There is an app called Mobile Observatiry which is excellent for this sort of thing too.

[pandoraefretum]

I really appreciate all these answers; they are all very good...
I will study each very carefully

Yes, my latitude and declination of Saturn nebula is all I need...
I also noticed the graph function can help me....
Still, IMO, there's room for a function which calculates the optimum / ideal time during the year to observe any given object 
Thx again, Roland

[Whirlwind]

The astronomical way of looking at this is to use your local sidereal time (LST), which to note is NOT your local time.  Your LST is the RA at any given moment that is crossing the meridian (south in the northern hemisphere; north in the southern hemisphere).  You can find your LST in sky safari pro under date & time settings tab under advanced.  Therefore any object is highest when the RA of the object equals the LST.  You can simply find out how long it will be until (or how long after) an object has passed this point by taking the LST and minus the RA of the object.  So at the time of this post my LST is about 3hrs 30.  The RA of the Saturn Nebula is 21hr 05.  21 - 3.5 = -17.5 hrs. In effect you are 17.5 hours from the point that the Saturn Nebula will again be highest in the sky.  Alternatively by considering a 24 hr timeframe you are 6.5 hrs since it last passed the meridian.  This is called the 'hour angle' which tells you how long until the object crosses the meridian or after; in this case your hour angle (HA) would be +6.5.  If you take another case when your LST is 19.5 hrs then it would be 19.5 - 21.0 = -1.5 hrs.  In this case your HA = -1.5hrs (i.e. you need to wait another 1.5 hrs until it is at its highest).  

To determine when an object would cross the meridian at your local midnight you need to consider when RA = 0 at local midnight.  This happens on the 21st September (RA=12 hrs on 21st March).  Now we know there are 24 hrs on the RA scale and roughly we have 12 equal months.  That means for every month this equates to about 2 hours.  Hence for every month after 21st September the RA that will be at the meridian at local midnight will have progressed 2 hours (so on 21st October the RA at midnight would be approximately 02:00:00*.  On 21st August your RA at local midnight would be 2 hours earlier (i.e. approximately RA=22:00:00).  Now we know the Saturn Nebula has an RA of 21hrs.  That equates to about 1.5 months before 21st September.  Therefore you should find that the highest point at local midnight is around 6th August.  This is different to lenscap's time because of BST, his statement assumes local midnight is at 12am, but its not, its actually about 1am in the UK because BST is Universal Time +1 hour.  I say 'about' because your local midnight will vary by a few minutes dependent on how far east or west of Greenwich your are. Generally you can use Greenwich in the UK as most places (barring perhaps Isles of Scilly) are close enough to Greenwich not to worry about this. You can see a much greater effect when you go to the Canary Islands.  Their Local time is Spanish time but they are good deal further west and hence mean local time is 18 degrees or so west of this meaning astronomical cycles can happen about an hour later than your expect them to (e.g. setting /rising of the sun).

Hence you can easily work out when *any* object will peak at midnight just by considering the RA of the object

0 Hrs RA - Late September
1 Hrs RA - Early October
2 Hrs RA - Late October
3 Hrs RA - Early November
4 Hrs RA - Late November
5 Hrs RA - Early December
6 Hrs RA - Late December
7 Hrs RA - Early January
8 Hrs RA - Late January
9 Hrs RA - Early February
10 Hrs RA - Late February
11 Hrs RA - Early March
12 Hrs RA - Late March
13 Hrs RA - Early April
14 Hrs RA - Late April
15 Hrs RA - Early May
16 Hrs RA - Late May
17 Hrs RA - Early June
18 Hrs RA - Late June
19 Hrs RA - Early July 
20 hrs RA - Late July
21 Hrs RA - Early August
22 Hrs RA - Late August
23 Hrs RA - Early September

*Note this isn't quite right because months aren't split equally across the year but is a close enough approximation

 

 

[Stu]

That's really helpful, thanks Whirlwind.

I wasnt too far off with my 16th August guess above but went back and reviewed based on your info and found that it transits the meridian at 1am on 8th August, pretty much where you said 👍👍👍

[Gfamily]

As has been said, objects will be at greatest height above the horizon when they are on the meridian (due south), and this varies at different times of night at different times of the year. 

If you get a 'proper' planisphere (plastic or card rather than electronic) it may help you get a better understanding of how objects appear in the sky, and show how if something is south at midnight on a date in August, a month later it'll be there at 10pm, and at 8pm in October.