Why can't i see M51

[rockystar]

Admittedly, my garden is pretty light polluted and I have no real expectations of being able to see it from there. However, looking at the Surface Brightness of M81 and M82 (which i can see pretty easily from my garden), M51 has an SB in between M82 & M81;  should that then mean that i should be able to see it, or am i missing some other factor(s).

M81: SB 13.3

M82: SB 12.35

M51: SB 12.56

(values taken from Stellarium)

[wookie1965]

I live not far from you I have never seen M51 from home only ever seen M1 once you definitely need dark skies see it.  M81 and M82 I can get in my 4" refractor but M51 even in the 8" eludes me. 

[Knighty2112]

M51 is tricky with LP in the way, however it can be seen on relatively good nights. Look for a faint pair of eyes staring back at you. Definitely should be doable with your 200p.

 

[vlaiv]

Surface brightness reported by Stellarium (and in general, quoted surface brightness of galaxies) is average surface brightness - expressed in magnitudes per arc minute. Emphasis here goes on average - take two galaxies with same surface brightness, one having very bright core (or cores - like M51) and other being relatively "smooth" with no particular high brightness spots (like M82). High core and low surface brightness spiral arms on average give off same amount of light as medium brightness all over the place (10 and 2 have the same average as 6 and 6). This is why you will struggle to see any nebulosity around M51 core, but core(s) (that of M51 and NGC 5195) should be visible in 8" even in LP if night is good.

I manage to see two "spots" of M51 in 8" almost regularly from my LP (Mag 18.5) polluted back yard. Only once or twice I was able to discern that there is some sort of nebulosity around those. On the other hand, same scope in mag 21.1 mag skies, on a particularly good spring night showed it all - spiral arms, bridge, cores - magnificent sight (wonder what it would look like from truly dark site - mag ~22, or using larger scope).

Just to add - try to observe it when it is highest in the sky - this time of the year is not really good for M51 - early spring should be your target "window".

[david_taurus83]

I live on the outskirts of Brum and have 3 streetlights looking into the back garden. With the 200p I can just, just make out M51 with averted vision and a 25mm eyepiece. It's very faint. M81 and M82 are much brighter imo. Sky quality on the night is important. I have even glimpsed M1. Very very very faint. Of course, all captured via Goto. I have neither the skill or experience to find these objects manually.

[ronl]

I can observe them from my garden, I do have LP, as long as the Moon is out of the way, and the

seeing is reasonably good. I can't  find it though a 27mm , I tend to use an 18mm and once I am on it

I use a 12mm which gives a reasonable view, you don't get those wonderful spiral arms that you see

in images, but you get both in the same field of view, I also use an observing hood, which helps alot.

[rockystar]

Thanks all. I don't have trouble finding the right area for it,  it's a pretty easy hop. And I have seen it at a dark site (it was wonderful - want to try bigger and darker though), it just seems like I should at least be able to make out the core from the garden,  but never had any luck.  Maybe just keep trying and I've not had very transparent nights when I've tried. 

[Charic]

4 hours ago, rockystar said:

i should be able to see it, or am i missing some other factor(s).

Must be that crappy scope you're using?

Hold on! ........wait a minute!......at least four of us are using a 200mm apertured scope, so it can't be that bad ?

To date, I have not seen M51 or M101 from my garden, but with the new street lighting, and a slightly darker garden, that may change this season.

[Stu]

I've always found it tricky, and basically not possible from my mag 18.5 skies but that's generally in a 4" refractor. Very easy from a dark site though. It is always smaller than I expect.

You've seen it before and know where you are looking so I guess it is just a matter of trying different nights to get some decent transparency.

[kirkster501]

M101 is the same, very faint and diffuse.  A very, very faint and ghostly smudge.

You need dark skies to have any hope of seeing any of these face-on spirals - even M33 is tricky.

[vlaiv]

3 minutes ago, kirkster501 said:

M101 is the same, very faint and diffuse.  A very, very faint and ghostly smudge.

You need dark skies to have any hope of seeing any of these face-on spirals - even M33 is tricky.

I barely observed M101 from a dark site - it has much lower surface brightness and not as nearly bright core as M51 - or so I thought at the time.

[cloudsweeper]

From a Merseyside suburb I have seen M51, M1 (although faint), M97 (Owl Nebula), and recently M33 with a 10" aperture.   Getting the target area dead right then using patience, AV, and varying magnification helps with elusive objects.  I hope that UMa galaxies M101, 108, and 109 will succumb to my probing in these dark nights very soon!

For a given SB, a galaxy with a concentrated core of light will be easier to see than a more uniform one.

Doug.

[SIDO]

I have somewhat dark skies and for me M51 is more a summer object and better viewed nearer the zenith, at that time of year it is a marker galaxy letting me gauge the seeing by its presence, if I can see It then the catseye can also be seen and so on. Some nights even though a milkyway is observed M51 is absent on other nights were the milkyway is very faint its easily seen so a good indicator of the seeing. I don't think it's a dependable target under light polluted skies as its currently placed, beautiful galaxy to observe though indeed...

[bish]

I could see M51 with my old SW 150 from Dudley. The LP in general is about as bad as it gets,  but my flat was on high ground and definitely had less of the murk I now see from my garden that sits in a dip.  I'll have to try with my 127mm mak. M81 and 82 can be spotted in bins from my garden, but not M51.

[noah4x4]

I never once saw M51 from my urban light polluted back yard despite having a decent 8" scope and expensive eyepieces.  However, I put my Atik camera on Hyperstar and in under 30 seconds at first light had a clear detailed near live image on screen embracing its very hard to see spiral arms.

I highly recommend Electronically Assisted Astronomy where light pollution is severe, and if you have a Fastar compatible OTA do consider Hyperstar. As it typically reduces a scope from f/10 to f/1.9 images that might normally take nine minute exposures can be produced in under 30 seconds, hence no need for polar alignment or autoguiding. I have been able to abandon my heavy wedge and with a IDA D2 LP filter it cuts through the mirk. Works superbly with Alt-Az or GEM. 

[Mr niall]

Tried every clear night for about 3 months in the and never saw it... it’s an absolute nightmare. Honestly if you haven’t found it by now you won’t!

[JohnSadlerAstro]

Hi,

I'm honestly really surprised about this--although its an awkward one to find I always thought that M51 was about the same brightness as 81 & 82 etc. I have pretty standard country town bortle 5-4.5ish (mag 20.5) and I could see it with my old Explorer 130/900. ?

It is a bit different looking to the others though--almost like a fuzzy double star. Perhaps the low elevation is making it difficult to see?  

John

[John]

M51 is not difficult to see with a small scope when it's high in the sky.

Currently it's pretty low though and low targets have their brightness extinguished more by the atmosphere. Stellarium approximates this as an option and right now (for example) it indicates that M51 has "lost" around a magnitude because of it's low elevation.

When Canes Venatici is riding high in the sky (say, by the end of February ) this target should be somewhat easier to pick up.

M51 and NGC 5194 remind me of a pair of ghostly "eyes" peering back at me when I've seen them with small scopes. With a 20" dobsonian at the SGL star party a few years back, they looked like this

 

[Mr niall]

5 minutes ago, John said:

M51 is not difficult to see with a small scope when it's high in the sky.

Currently it's pretty low though and low targets have their brightness extinguished more by the atmosphere. Stellarium approximates this as an option and right now (for example) it indicates that M51 has "lost" around a magnitude because of it's low elevation.

When Canes Venatici is riding high in the sky (say, by the end of February ) this target should be somewhat easier to pick up.

M51 and NGC 5194 remind me of a pair of ghostly "eyes" peering back at me when I've seen them with small scopes. With a 20" dobsonian at the SGL star party a few years back, they looked like this

 

I live in Bortle 5 and could see nothing when it was pretty much at it’s azimuth with 130mm (127 Mak and a 130mm reflector), if I hadn’t photographed it I’d still be of the opinion it doesn’t actually exist ?

[John]

I've seen it with 11x70 binoculars (usually challenging) and often with scopes from 100mm in aperture from my back garden. The best nights here are around NELM 5.5.

 

 

[Stu]

2 minutes ago, John said:

I've seen it with 11x70 binoculars (usually challenging) and often with scopes from 100mm in aperture from my back garden. The best nights here are around NELM 5.5.

 

 

That extra 0.5 mag makes quite a big difference John. I've seen it easily with 15x50 binoculars from a similar sky, but it is much more difficult with some more LP. Quite right about the altitude helping though.

[michael.h.f.wilkinson]

I have seen M51 as a little smudge in 10x50 bins, and it is fairly easy in my 16x80 bins from my (comparatively dark) suburban skies when it is high enough. When low in the sky it is near impossible to see. M81 and M82 are much easier.

[Ricochet]

I've found that M51 is one of those galaxies that can be improved by an (astronomik) CLS filter. How much light pollution it can help with I don't know and it's a fairly expensive test to try as you could buy several dark sky trip's worth of fuel instead. 

[John]

I recall one response on another forum to the question "what can I buy that will improve my view of galaxies ?". The response was "A tank full of fuel to get you and the scope under dark skies".

Probably a sound suggestion !

[rockystar]

3 hours ago, Ricochet said:

I've found that M51 is one of those galaxies that can be improved by an (astronomik) CLS filter. How much light pollution it can help with I don't know and it's a fairly expensive test to try as you could buy several dark sky trip's worth of fuel instead. 

 

2 hours ago, John said:

I recall one response on another forum to the question "what can I buy that will improve my view of galaxies ?". The response was "A tank full of fuel to get you and the scope under dark skies".

Probably a sound suggestion !

 

Yeah, i need a few trips out this season. And as much as i agree with the statement, i'm not always a fan of its use - it isn't always possible to get away from home (maybe you don't drive, or have children/other commitments), and when you can't, you want to be able to maximise what you can do from the back garden.