Anyone observed NGC 3003?

[Ships and Stars]

Hi all,

Last night I set up the 20" dob at home for a clear three hour weather window which was accurately predicted by MetOffice down to 15 minutes! I usually use the 300p flextube at home and save the 500p for dark sky trips, but these days, well, you know...

So anyway, I did a Synscan align on Capella and Pollux which turned out rather good, and as a result, started hoovering up a lot of the solitary outlying galaxies in Leo and UMa shown in the S&T Pocket Atlas. Skies were decent for my location - Unihedron SQM-L read 20.20 to 20.34 SQM and no high cloud was detectable. All neighbouring lights were off (love it).

I really enjoyed being able to fairly easily located these faint fuzzies with the GOTO, but one in particular stood out - or rather, barely stood out - NGC 3003 which is between Leo Minor and the 'head' of Leo (top of p.35, S&T Atlas).

Using the 9mm APM, I slewed across and quickly caught it with averted vision, then once settled in, was able to see it with direct vision but it was a seriously, seriously faint edge on galaxy, especially in comparison to the other NGCs in the S&T Atlas. In my scope around 11:20pm, it appeared as a nebulous extended narrow faint streak orientated vertically with no hint of structure or detail. Swapping to the 10mm BCO, I noticed, as with other galaxies last night, the background sky seemed a lot brighter and less contrasty. Using the 10mm BCO on NGC3003, it actually frequently went in and out of vision and was quite difficult to see over the 9mm APM which seemed more forgiving. I reckon the 10mm can be explained with higher light transmission combined with a bit of LP, perhaps a try at a really dark site will let it shine.

Anyway, my curiosity now going, I went in afterwards and checked Stellarium which says it is mag 18.34 with surface brightness of 19.41! No way I'd be able to see this in theory, right? And what's it doing in the S&T Pocket Atlas then? Hmm...

So for a second opinion, I went to Telescopius which gives a mag of 11.9 and 22.8 surface brightness. Wikipedia says 10-something mag?

Q: Has anyone observed NGC3003 before, and what do you reckon on these mag estimates? The numbers seem all over the place and beyond the reach of my dob which goes to about 16.4mag in theory (for single point light sources I presume). 

I've attached a screenshot from Telescopius for some idea, though of course through the eyepiece the surrounding stars were much brighter than this very faint but intriguing (to me) fuzzy...

 

Edited March 28, 2020 by Ships and Stars

[jetstream]

There are different fluxes with their own number, NGC 3003 is a bright 6x1.3 is arc min (large) galaxy right around mag 12. It is easy in my 10"..

Orthos can take getting used to on these objects- eyeplacement in particular IMHO.

http://simbad.u-strasbg.fr/simbad/sim-id?Ident=ngc3003&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id

[Ships and Stars]

Just now, jetstream said:

There are different fluxes with their own number, NGC 3003 is a bright 6x1.3 is arc min (large) galaxy right around mag 12. It is easy in my 10"..

Orthos can take getting used to on these objects- eyeplacement in particular IMHO.

http://simbad.u-strasbg.fr/simbad/sim-id?Ident=ngc3003&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id

Thanks Gerry! It was fairly large actually at c.200-222x. I think the LP here is much worse than what I am used to with the 20", which generally only sees dark skies.

I was teetering on the ladder last night, couldn't get a level placement, so it was quite wobbly looking through the EPs.

The 10mm BCO is very sharp! I'm definitely keeping it and am hoping to get more time with it. I am completely new to orthos as well.

Conditions combined with my overall inexperience I think were showing a bit last night, didn't see any of the small PGCs shown on Stellarium, but only had the S&T Atlas outside.

I wish the synscan controller had PGCs in the catalogue, but will start using SAO stars to get as close as possible.

[jetstream]

Just now, Ships and Stars said:

Conditions

This was the issue IMHO.

The magnitude scale is not linear "The scale is logarithmic and defined such that each step of one magnitude changes the brightness by a factor of the fifth root of 100, or approximately 2.512"

There is a massive difference between 20.3 and 21.3 mag skies IMHO and every bit past this is that much darker.

Of course with galaxies we also have size and therefore surface brightness considerations and the more I learn about galaxies the less I realize I know. Listed magnitudes are derived from flux magnitudes have a couple of formulas to convert to "V" mag. Some shapes seem harder at the same size and mag IMHO.

The best on this is @mdstuart IMHO.

Congrats for seeing this under challenging conditions Robert.

 

[Ships and Stars]

Thanks for the information, a lot of new info really. Log scale sounds right, I've seen (detected) the HH with the 300p under 21.6, but never got it with the 20" at home on the best nights. Flux mag is a totally new one for me, at least I have more time at the moment to read up on all of this. Might even have to blow the dust off my scientific calculator if the ancient battery hasn't eaten the inside yet!

[mdstuart]

I observed ngc3003 in Feb 2018 in my former 16 inch scope. My note says it was a lovely large oval low surface brightness object requiring averted vision.

Low surface brightness galaxies like these are more sensitive to the transparency of the sky. I also sometimes find larger objects are easier to see at lower magnifications so experiment.

I will have to go back with my 10mm bco eyepiece 😉

Thank you for sharing your observation Robert.

Mark

[Ships and Stars]

15 minutes ago, mdstuart said:

I observed ngc3003 in Feb 2018 in my former 16 inch scope. My note says it was a lovely large oval low surface brightness object requiring averted vision.

Low surface brightness galaxies like these are more sensitive to the transparency of the sky. I also sometimes find larger objects are easier to see at lower magnifications so experiment.

I will have to go back with my 10mm bco eyepiece 😉

Thank you for sharing your observation Robert.

Mark

Thanks Mark, that backs up Gerry's view on conditions, there certainly could have been some high wispy cloud sneaking past which would explain it disappearing a bit at times, plus there's more LP here than I'd hoped once I took a proper reading.  I'm actually hoping to get the 300p out tonight as the weather shows a bit of a window, should have kept the 500p out but started sleeting here this morning. If conditions cooperate, I'll go straight back to 3003 and get relaxed and see if I can flush it out and experiment with the 10mm BCO some more. I don't use the winged eyecup on my other Baaders, but the one on the BCO works great, don't need a hood at all, except for temperature, pretty low today!

[Ships and Stars]

PS I should have tried it with the 13mm and even perhaps the 20mm or 17.5 Baader, wondering what various exit pupils/mag will do on these sorts of objects. Was also thinking if I had just popped the BCO into the focuser, that meant I had my red LED on nipping over to the EP case, so there's a good chance I didn't settle with it enough to re-adapt fully. That's another question I was going to ask about sometime, regarding red LEDs/LP and 're'dark adaptation, but I'll give everyone a break for a bit, lol.

I have lots of reading to do on various aspects connected to this which I thought I already had a decent grip on, but then again, that's part of what I like about astronomy. I also think my definition of very faint might be someone else's 'decent', haha. 

I've still not had much luck with the smaller PGCs, but never really got into a groove this year, most of the clear nights here have been way too windy to really chase these sorts of objects. 

[mdstuart]

The one problem with the 10bco is it makes my nose cold. Is that the same for you?

Mark

[Ships and Stars]

Just now, mdstuart said:

The one problem with the 10bco is it makes my nose cold. Is that the same for you?

Mark

Haha it is a proper lump of steel for the size isn't it? One thing that jumps out is despite its size, it has a bit of heft to it which suggests they put some effort into it. It's going to be a cold one here tonight, I'll probably notice it now you mention it 🤣

Actually I didn't notice it much last night, but perhaps that's down to eye placement which needs some fine tuning?

[jetstream]

12 minutes ago, Ships and Stars said:

red LED on nipping over to the EP case, so there's a good chance I didn't settle with it enough to re-adapt fully.

On top of transparency and lowish darkness you might have wrecked the chemical part of dark adaptation...

From Vogel: "Dark adaptation

Let's summarize this:

	Opsin, which if formed after a light event from activated rhodopsin is weakly active and makes the photoreceptor cell "see" virtual light even in complete darkness and prevents thus complete dark adaptation.
	Only after about 30 minutes, opsin is completely regenerated to inactive rhodopsin, allowing complete dark adaptation of the cell.
	Dark adaptation relies mostly on the switching-off of the activity of opsin and only to a very minor degree on the increase of the total amount of rhodopsin by regneration."

[Ships and Stars]

3 minutes ago, jetstream said:

On top of transparency and lowish darkness you might have wrecked the chemical part of dark adaptation...

From Vogel: "Dark adaptation

Let's summarize this:

	Opsin, which if formed after a light event from activated rhodopsin is weakly active and makes the photoreceptor cell "see" virtual light even in complete darkness and prevents thus complete dark adaptation.
	Only after about 30 minutes, opsin is completely regenerated to inactive rhodopsin, allowing complete dark adaptation of the cell.
	Dark adaptation relies mostly on the switching-off of the activity of opsin and only to a very minor degree on the increase of the total amount of rhodopsin by regneration."

Solid gold! Thanks again. I was hopping around a lot last night, even nipped into the house to check Stellarium on my desktop but installed a red filter on my desktop thinking I'd re-adapt pretty much instantly.

I did finally settle a bit towards the end of the session, but still was using the red LED intermittently maybe once every 5-10 minutes to make sure my power cable didn't get pinched when the scope slewed.

When I'm out at a dark site, it's a different story and think I am getting dark adapted much better there than here on the edge of town.

I'd heard of rhodopsin but not opsin. I'd even ate more carrots once I'd read about rhodopsin, though the carrot aspect may have gained an element of myth from British WWII pilots who claimed it gave them increased night vision because they didn't want the Germans to know about the success of radar apparently!  

[jetstream]

If I am in the sun all day or watch the LED TV my dark adaptation can really suffer, even way later on. M42, Sirius, Jupiter etc wreck my adaptation too- the Sky Commander dim green screen is in question too. Lots to think about if trying to get the faintest ones dancing into view.

Many of the most serious DSO observers promote the use of the observing hood, which can help keep out stray, eye wrecking light.

Edited March 28, 2020 by jetstream

[Ships and Stars]

21 minutes ago, jetstream said:

If I am in the sun all day or watch the LED TV my dark adaptation can really suffer, even way later on. M42, Sirius, Jupiter etc wreck my adaptation too- the Sky Commander dim green screen is in question too. Lots to think about if trying to get the faintest ones dancing into view.

Many of the most serious DSO observers promote the use of the observing hood, which can help keep out stray, eye wrecking light.

Indeed! My LED headlamp requires me to cycle through blue, then green until I get red, so I close my eyes for two clicks, but often end up on green. The red LED is quite bright as well and on more than one occasion, have accidentally hit the main bright beam which really is a bit of a shock to the eyes at night. I've taped over the coloured red LEDs, but it can still pump out the light, especially if I'm holding the atlas up to my face checking objects. 

I bought an arctic snorkel hood mainly for my binoculars with filters, because the filters are external they will reflect any light whatsoever. I'll dig it out tonight, it's hilarious looking, but definitely like sitting in a tunnel!

I think in hindsight, it's a lot trickier here getting dark adapted in town than I've considered. 

Lots of good points here Gerry and Mark, thank you both! 

[jetstream]

18 hours ago, Ships and Stars said:

I think in hindsight, it's a lot trickier here getting dark adapted in town than I've considered. 

It can be very hard, for me too. One look at a light even 800 yds away can wreck things. Thing is I seem to chemically adapt faster now, going from dark blind to full seeing (can see in the dark) in about 15 mins. So I do believe that repeated true dark adaptation speeds things up, however this assumes we havnt wrecked our eyes during the day.

Another thing- totally agree with Mark about the lower mag thing- I always sweep the area with the 20mm Lunt and more recently the 17.3 Delos, which is superb for this. I like seeing the field stop on faint, small galaxies- that dark edge seems to enhance perceived contrast on these ones, assuming the EP is good in the first place.

Thing is all these little tricks are a personal thing and for general, relaxed fun viewing I like hyperwides, espc on nebula. I really don;t like seeing the FS on these objects, globs either.

Have you read Clarks take on things or Blackwells? More needed pieces to fill in the puzzle.

 

"Optimum Magnified Visual Angle

A low-contrast object is more easily detected if it is larger. For an extended object such as a galaxy viewed in a telescope, magnification does not change the contrast with the background, because both the sky's and the object's surface brightnesses are affected equally. Some visual observers have stated that a dim object's contrast with the sky background increases with higher magnification, but this is clearly wrong. The contrast merely looks greater because of the increased detection capabilities of the eye. Clark (1990) coined a name for the maximum magnification that will help detection: the "optimum magnified visual angle" (OMVA)"

https://clarkvision.com/visastro/omva1/index.html

[jetstream]

@Ships and Stars I must also emphasize the conclusion-try everything and then let experience be your guide.

 

"What Does All This Mean?

To see all the detail in an object, use many powers, from very low to very high, examining the entire object with each magnification. Because the OMVA appears to be a shallow minimum, one need not be precisely on the optimum. Within a factor of 2 or a little less in magnification is fine. A magnification sequence of: 35x, 50x, 80x, 120x, 180x, 270x, 400x ... (a sequence increasing magnification by a factor of about 1.5) is great."

[Ships and Stars]

11 minutes ago, jetstream said:

It can be very hard, for me too. One look at a light even 800 yds away can wreck things. Thing is I seem to chemically adapt faster now, going from dark blind to full seeing (can see in the dark) in about 15 mins. So I do believe that repeated true dark adaptation speeds things up, however this assumes we havnt wrecked our eyes during the day.

Another thing- totally agree with Mark about the lower mag thing- I always sweep the area with the 20mm Lunt and more recently the 17.3 Delos, which is superb for this. I like seeing the field stop on faint, small galaxies- that dark edge seems to enhance perceived contrast on these ones, assuming the EP is good in the first place.

Thing is all these little tricks are a personal thing and for general, relaxed fun viewing I like hyperwides, espc on nebula. I really don;t like seeing the FS on these objects, globs either.

Have you read Clarks take on things or Blackwells? More needed pieces to fill in the puzzle.

 

"Optimum Magnified Visual Angle

A low-contrast object is more easily detected if it is larger. For an extended object such as a galaxy viewed in a telescope, magnification does not change the contrast with the background, because both the sky's and the object's surface brightnesses are affected equally. Some visual observers have stated that a dim object's contrast with the sky background increases with higher magnification, but this is clearly wrong. The contrast merely looks greater because of the increased detection capabilities of the eye. Clark (1990) coined a name for the maximum magnification that will help detection: the "optimum magnified visual angle" (OMVA)"

https://clarkvision.com/visastro/omva1/index.html

Thanks Gerry! I should have dropped to the 13mm or the 20mm for a look at 3003, I bet the exit pupil and lower mag would have made a significant different in hindsight. Even when I had my Leica zoom, I'd rarely go above maybe 150x and that night I'd used almost the 10mm and 9mm exclusively, so 200x and 222x, a lot more than I normally go except lunar and planetary nebulae.

 I'd like to read up on how green led light affects dark adaptation, I tend to use this a bit more than red when setting up. I did see somewhere it has a similar effect as a red LED, but takes a bit longer to adapt. 

I think perhaps LEDs in general seem to have a harsher impact on adaptation, though I've no evidence at the mo to back this up. 

Thanks for the links to Clark & Blackwell. I love reading about the physiology as much as the gear and mag/exit pupil etc. Still pretty new to the galaxy hunting for sure.

Good stuff Gerry! Hoping for another bash, set up the 300p last night based on totally conflicting weather forecasts, and the cloudy one won!

[jetstream]

1 minute ago, Ships and Stars said:

Thanks for the links to Clark & Blackwell

Do you want a VG practice ground to illustrate Marks comment? his note supports Clarks idea. I have practised this concept quite a bit.

[Ships and Stars]

2 minutes ago, jetstream said:

Do you want a VG practice ground to illustrate Marks comment? his note supports Clarks idea. I have practised this concept quite a bit.

Sure! 👍 I haven't read the Clark site fully but see surface brightness decreases with mag which makes sense, but contrast remains steadfast though our eye sees it differently based upon size in the EP.

[Ships and Stars]

This image is pretty interesting too, a good illustration of perception and contrast. I was just thinking, even though I sold the Leica to help buy the APMs, I still have a Seben 8-24mm that is ok to use. It doesn't have clickstops so I might try to steadily zoom in on 3003 or any other relatively low surface brightness object and note how changing mag impacts the views and detection.

[jetstream]

28 minutes ago, Ships and Stars said:

the sky's and the object's surface brightnesses are affected equally.

they are dimmed equally... a "contrast" expert would bounce up and down with misconceptions- believe me I know lol!

Making a galaxy larger makes it easier to see up to the trade off point of illumination of the eye.

First off Mark has been a true help in my pursuit of viewing galaxies, he is an excellent galaxy man.

Second, viewing galaxy cores can be different (take much more mag) than the more diffuse galactic cirrus.

To illustrate Marks and Clarks point M51 is a great observing lab, and one which Clark uses. This object has been a mainstay of mine with many tens of hours spent on it. When you view M51 with lower mag the spirals will be buried in galactic glow. Its the same as seeing NGC 3003.... lower mag increases visibilty because of its nature.

Upping mag on M51 reveals much more defined spirals - my 15" will take 228x at f4.8 on it. Differing mags enhance differing features because there are visible features that can be enhanced.

Some galaxies have no more visible features so mag must be adjusted accordingly, lower in the case of the large NGC 3003. Take a small galaxy core and I've gone way over 400x.

I just ran across this in Markarians Chain on NGC 4402- low mag revealed a hint of structure, more revealed true mottling.

 

Edited March 29, 2020 by jetstream

[Ships and Stars]

This is fascinating, never thought I'd be this interested in low light vision and detection, etc.  

PS, I'm a bit embarrassed to say it, but two nights ago was the first time I observed M51, and thought you fool, why didn't you look at this before!

It was spectacular even under 20.20-30 SQM and I can only imagine what it looks like in proper darkness.

I can see how you could spend a lot of time studying it with different magnifications.

Wishing we have a few more clear nights before the moon is back in control, but there is still a very small window of time under next month's new moon from midnight to c. 2:30am.

[jetstream]

Just try a bunch of things Robert, doing this will allow you to predict what eyepiece you might need. These days I enjoy pulling out feature in objects like M33, M101, NGC 2403 and a whole host of others. Your big dob will do the same. Very happy to get structure in Markarians Chain.

There are a couple of observers that have really advanced their observing skills, yourself and @Littleguy80 kudos to you guys, it really takes work and determination.

[Ships and Stars]

16 minutes ago, jetstream said:

Just try a bunch of things Robert, doing this will allow you to predict what eyepiece you might need. These days I enjoy pulling out feature in objects like M33, M101, NGC 2403 and a whole host of others. Your big dob will do the same. Very happy to get structure in Markarians Chain.

There are a couple of observers that have really advanced their observing skills, yourself and @Littleguy80 kudos to you guys, it really takes work and determination.

Thanks Gerry, you and everyone on here have helped a ton. Great forum. Wish I'd bought mirror grinding supplies for this summer, but still plenty of other non-astro things to fix and with all the time I'll save not chasing holes in the clouds around NE Scotland, I'll be able to catch up on reading! Lunar will still be on, looking forward to that, and might even try to see what DSOs I can tease out in May just for laughs.

Edited March 29, 2020 by Ships and Stars

[Littleguy80]

16 minutes ago, jetstream said:

There are a couple of observers that have really advanced their observing skills, yourself and @Littleguy80 kudos to you guys, it really takes work and determination.

Thank you, Gerry. I have had some excellent mentors along the way, yourself and Iain @scarp15 included. Very much echo your point on experience. So much comes from just observing as much as you can and experimenting while you’re out there. We’re all individuals and what works for one person won’t necessarily work for another. 

I’d also give a big thumbs up to an observing hood. I believe mine makes a big difference to what I can detect.