6 replies to this topic

[Daveatvt01]

I came across this globular cluster while looking up some spring clusters for April, in case transparency was negatively affecting galaxies. It can be windy here in the springtime which kicks up a lot of dust.  

 

 

The core was mottled, but not quite resolved, even at 367x in the 17.5".

 

[itsjack]

Your sketch is awesome, it's very reminiscent of what I see when I look at the brighter globular clusters through my smallish telescope. I've never sketched a globular cluster before and I'd like to, is there a chance you could comment on your method as to help a newbie out?

It's also interesting that a globular cluster would be in Virgo, I wonder why that is.

[Daveatvt01]

Thanks! I used black Canson paper, white charcoal pencil, charcoal stick, and a paint brush. I draw the field stars first. Then I rub charcoal on 600 grit sandpaper to make a charcoal powder and apply the powder to the paper for the background glow of the cluster. Then I fill in more visible stars with the charcoal pencil. 

If you are using pencil and paper, you can lightly pencil in a circle and use a blending stump for the background glow instead of powder.

 

There are several other springtime GC's in the vicinity, like M3, M5, M53, NGC 5694 and NGC 5053. This is the only one that happens to be in Virgo. Wiki says it was "once a likely member of the Sagittarius Dwarf Spheroidal Galaxy." Pretty neat!

 

Give it a try!

[itsjack]

Thanks for your method, its very useful. I was practicing sketching M13 today, and used some of your tips. 

 

It's interesting that NGC 5053 came from one of the Milky Way's dwarf galaxies. That makes me wonder if there are any other GCs that may have originated from dwarf galaxies. I think Omega Centauri is speculated to actually be the remnant of a dwarf galaxy, but it would be interesting to see if there are any other globular clusters with interesting history. 

 

A very interesting target, wonderfully sketched!

Edited by itsjack, 18 May 2025 - 04:19 PM.

[bphaneuf]

That's the Mellish technique and very fun way of producing drawings of GCs.  A mop brush is great for the overall halo,and a stipple brush for really concentrated cores.  You can use the mop, a smaller mop or a mini fan brush to blend the two areas.  Keep those pencils sharp for the stars!.  For very resolved clusters with bright stars in the core and/or standouts in the halo, various sizes of white gel pen work well as it's hard to get stars to stand out against the heavy powder layer in the core.  Go light with the powder at first.  You can always build it up and too much makes a mess.   NGC 4147 is around 60 kly away, but still resolved in the 24 and so similar in appearance to 5634.  The Mellish technique and mop brush make the halo fairly efficiently as they'll naturally be more concentrated at the center and fade evenly to the edges.  You can vary the effect based on the amount of powder you use and the size of the brush.  Here's the effect on various GC core concentrations, conditions and magnifications.  Vary pencil hardness for bright to faint stars.  A very sharp hard pencil and very light pressure will render those barely resolved stars that come and go.

 

 

 

 

-b

Edited by bphaneuf, 18 May 2025 - 04:56 PM.

[itsjack]

Woah!! 

 

Those are some awesome sketches b. I have heard great things about the Mellish method, and it looks like it works very well with globular clusters. 

 

I hope one day to be able to sketch to the quality that I've seen in this thread, all the sketches here are mindblowing!

Edited by itsjack, 19 May 2025 - 12:25 PM.

[bphaneuf]

Thanks John!  Keep doing what you’re doing and you’ll be there in no time.  This is my M13 from 4 years ago:

 

 

-b

Edited by bphaneuf, 19 May 2025 - 01:41 PM.