Deep Sky Magnification

[fifeskies]

Aled

I would say M51 whirlpool is not one of the easier targets with a scope of 100mm aperture , especially when we are in (bright) summer skies.

Also the "seeing" has not been great of late due to a turbulent jet stream above the UK last few months making it more difficult.

 

You will also need to allow 20 to 30 mins for your eyes to dark adapt fully before chasing a dimmer DSO.

 

Is there any light pollution around you as a Bortle 4 sky can still be ruined by nearby bright floodlighting.

[Mr niall]

2 minutes ago, Aled B said:

may i give and example the  m51 whirlpool galaxy is south of the vega star and i can see the two stars where it is located but not been able to see it. as i have a x62.5 as best without the barlow is it a case of skies not clear enough or being in patient or any other factors?

M51 is actually next to Alkaid in Ursa Major....

Honestly ignore the barlow for now.

do a quick google for a star chart - something like this:

https://freestarcharts.com/messier-51

Study the chart - have a look at where M51 is relative to the other stars in the big dipper - for example if you have a look at M51 it is quite easy to find as it forms a nice right angled triangle with Alkaid and Mizar. Make a note of the degrees of separation. M51 is about 4 degrees away (give or take). It would be handy at this point to remember that the lower power eyepiece you use, the wider the field of view your telescope will give you.

But... M51 is a notoriously difficult target. I live in bortle 4/5 skies and I have never seen it in anything less than a 12 inch scope - and even then it was very very faint. Some people will tell you it is incredibly easy, it really depends on local conditions.

At the moment - I would concentrate on maybe M44, or perhaps M3 - or M81 / M82. They are easier to find and quite bright.

[Aled B]

11 minutes ago, Mr niall said:

M51 is actually next to Alkaid in Ursa Major....

Honestly ignore the barlow for now.

do a quick google for a star chart - something like this:

https://freestarcharts.com/messier-51

Study the chart - have a look at where M51 is relative to the other stars in the big dipper - for example if you have a look at M51 it is quite easy to find as it forms a nice right angled triangle with Alkaid and Mizar. Make a note of the degrees of separation. M51 is about 4 degrees away (give or take). It would be handy at this point to remember that the lower power eyepiece you use, the wider the field of view your telescope will give you.

But... M51 is a notoriously difficult target. I live in bortle 4/5 skies and I have never seen it in anything less than a 12 inch scope - and even then it was very very faint. Some people will tell you it is incredibly easy, it really depends on local conditions.

At the moment - I would concentrate on maybe M44, or perhaps M3 - or M81 / M82. They are easier to find and quite bright.

ideal thank you. i jst want to see one of them jst to get a feel of actually finding one. m44 it is

[fifeskies]

Like Nerf_Caching just said above as I said well back probably be a better idea to target M81 and M82

"  M51 the whirlpool is dimmer than the (relatively) nearby M81 which is easier to find and has a companion galaxy M82 which is smaller but can often be seen in the same view with low magnification eyepieces.   "

 

It is tempting to try to chase the objects we see in the glossy colour images from nice big telescopes but it is better to explore the capability of the scope you have .   There are always good things to enjoy with any size telescope.

 

"

[Aled B]

19 minutes ago, Mr niall said:

M51 is actually next to Alkaid in Ursa Major....

Honestly ignore the barlow for now.

do a quick google for a star chart - something like this:

https://freestarcharts.com/messier-51

Study the chart - have a look at where M51 is relative to the other stars in the big dipper - for example if you have a look at M51 it is quite easy to find as it forms a nice right angled triangle with Alkaid and Mizar. Make a note of the degrees of separation. M51 is about 4 degrees away (give or take). It would be handy at this point to remember that the lower power eyepiece you use, the wider the field of view your telescope will give you.

But... M51 is a notoriously difficult target. I live in bortle 4/5 skies and I have never seen it in anything less than a 12 inch scope - and even then it was very very faint. Some people will tell you it is incredibly easy, it really depends on local conditions.

At the moment - I would concentrate on maybe M44, or perhaps M3 - or M81 / M82. They are easier to find and quite bright.

to be honest i am quite lucky where im located. not much light pollution. this chart is perfect and just what i was looking. could you please expain the aparent mag to me?

Edited May 4, 2020 by Aled B

[fifeskies]

It wont be too long till M13 the Hercules cluster is back in the night sky

(at a reasonable hour , its there now for night owls)

This will be a good target for you to try.

 

M44 the beehive is good for the varied colours in the stars but it is an open cluster whereas M13 is a nice tight group.

[Pixies]

24 minutes ago, fifeskies said:

It wont be too long till M13 the Hercules cluster is back in the night sky

(at a reasonable hour , its there now for night owls)

This will be a good target for you to try.

 

M44 the beehive is good for the varied colours in the stars but it is an open cluster whereas M13 is a nice tight group.

I can find M13 in a pair of 10x50 binoculars in Bortle-6 skies. Not big and quite faint, but there.

It'll be a great target. My first telescope arrives tomorrow!

[fifeskies]

Aled asked about magnitudes

 

The apparent magnitude of an object only tells us how bright an object appears from Earth. 

It does not tell us how bright the object actually is as a big bright object far away will look dimmer than a less bright object much closer.

Its a logarithmic not a linear scale

 

 

Absolute magnitude is defined to be the apparent magnitude an object would have if it were located at a distance of 10 parsecs

ie all at the same distance which lets you compare how bright they are when beside each other

 

 

 

The lower the number the brighter the object is.

Mag 1 are bright stars , mag 6 cant be seen by most people unaided

 

Galaxies like          M81 are Mag 6.8 , too dim to be seen by naked eye

                               M51 is Mag 8.4 so is a LOT dimmer    

 

a difference of 1 Mag is about x 2.5 brightness     2 Mag is     (2.5 x) x ( 2.5 x)       or x 6.25

 

this means M51 is about 5 times dimmer than M81 which is why it is a lot harder to find in smaller telescopes.

 

Edited May 4, 2020 by fifeskies