September 2020 Challenges

[kt4hx]

I have observed the September northern challenge object , Messier 33, countless times over the years. Below are the notes from one of these observations from 2013 using my Z10 dob during a visit to our dark site area in the western part of the state.

Messier 33 / NGC 598 (Triangulum, spiral galaxy, mag=5.7, size=70.8’x41.7’, SBr=14.2):
This low surface brightness face-on galaxy in Triangulum was frequently just discernible naked eye, particularly with averted vision. In the 10x50 binoculars it was easily scooped up as a large and bright diaphanous oval glow. In the Z10 at 69x, it was quite bright and large angularly, presenting a bright core, with the arc of the spiral arms just discernible curling out from the core. Some small bright knots of H-II regions were also faintly seen in the arms, including the brightest of the lot NGC 604. An amazingly beautiful object that was made even more so by the dark richness of the skies at this location.

The southern object for this month, Messier 2, has likewise been observed numerous times. The below observation is also from 2013 with the Z10, but in this case from our typically lightly polluted backyard at home.

Messier 2 / NGC 7089 (Aquarius, globular cluster, mag=6.6, size=16.0’, class=2):
Moving southeast into Aquarius, to 2nd magnitude Sadalmelik (Alpha Aquarii), I then hopped just over 8 degrees to the west where the magnitude 6.6 globular Messier 2 slipped into the FOV of my 8x50 finder scope. At 69x in the Z10 it was somewhat small though very bright with a noticeably bright small core within a small symmetrical halo. The overall presentation was granular, hinting that at least some resolution might be possible. Moving through 89x, 114x and 142x it grew in visual size and core intensity, with the outer stars gradually becoming resolved. The core, however, remained intensely bright and tightly condensed.

[helicon]

Thanks for the report Alan. Nice catches.

[BABOafrica]

Always a joy to read your descriptions.

BABO

[KingNothing13]

Nice Alan! Sounds like I need to get to a good dark sky for a really good look at M33 - I've observed it from my yard twice - but each time, my notes say it was a "dim patch".

[kt4hx]

Thanks guys. I don't observe the Messier objects frequently any more because I've seen them so many times, but sometimes it is nice to re-visit them once in a while.

Brett, yes indeed, do get to a dark site. Dark skies are the great equalizer when it comes to diffuse extended objects. Less LP means less sky brightening that the feeble light from the object must overcome to be easily seen. I have always referred to the difference between our backyard at home (typically Bortle 5) to our dark site house (typically Bortle 3) as exponential. My 10 or 12 inch dobs used at the dark site compare favorably to the 17.5 inch used at home. That is why I call darker skies the great equalizer. Thus why I have the 17.5 inch at our dark site house full time now, so I get the combined advantage of larger aperture under darker skies.