Some Virgo Messier galaxies in short exposures

[Martin Meredith]

I finally got some clear skies over the last two nights and spent much of it in the fantastic galaxy ground that is Coma and Virgo. I'll post some of the deeper objects later, but here are three very different Messier galaxies in Virgo. All shots were taken with my alt-az mounted Quattro 8" f4 Newt, Lodestar X2 mono, no filters, no darks nor flats, with live processing in StarlightLive v3. Skies SQM 20.4 at zenith (the streetlamp in front of the house has been replaced by LEDs which has made quite a difference).

First, M61 in 4 x 15s. The last time I observed this was a couple of years back when the supernova appeared. On that occasion I recall setting my alarm for 4 am and desperately shooting through gathering mist in November; the detail was nowhere near as good but at least the SNR was clear. The inset shows the result of letting the stacking do its work. Not only is the background smoother, but the fainter outer spiral arms are beginning to show up. In practice, for an object with as much detail as thus I observe for at least 21x15s.

 

Here’s M87 with its famous jet (pointing NW in terrestrial terms). The main shot is a single 15s sub, with a 2-minute capture in the inset. The two tiny galaxies forming a dotted line to the NE are mag 16.1 UGC 7652 and mag 16.7 UGC 7652, and I was quite surprised to pick them up in this short an exposure. But what I find really remarkable is that the 15s sub has detected a little cluster of galaxies (encircled) which on further investigation via Aladin turn out to be members of a SDSS compact group collection (I only have mags 18.6 and 18.5 for two of the members). Although I've been using it for a while, the sensitivity of the Lodestar X2 continually amazes me.

 

Finally, M104, the Sombrero, which almost sits astride the Virgo/Corvus border. The main frame is a single 15s shot with the inset a total exposure of 2 minutes, again showing the main benefit in clearing up the background/allowing a bigger stretch.

I must say that I’m impressed by the defective pixel removal feature of StarlightLive 3. I didn’t take darks at all, and this enabled me to use a wide range of exposures during the session, from 1s to 30s. I don't see any hot pixel trailing in any of the shots from that night. Nice one, Paul!

Thanks for looking

Martin

[DoctorD]

Hi Martin

Some great images there - M101 in particular.

CS

Paul

[RobertI]

Some nice captures there, interesting to see the comparative effects of stacking, particularly on M61 which shows a lot of detail after 5 minutes.

[des anderson]

Amazing what you`ve captured,lots of detail.Des

[michael.h.f.wilkinson]

Very nice collection

[orion25]

Exquisite work, Martin. Great detail on M61 and M87, and the Sombrero looks ready to wear, haha!

Cheers,

Reggie

[johnfosteruk]

Cracking images, love the comparison, especially in 104.

[Astrith]

Great images....Alan.

[Martin Meredith]

Thanks to all of your for your comments and likes. Although I have no problems in spending many minutes with most objects, I think it is useful to see what is available one the first sub. As I use mean stacking in the main, the target object brightness doesn't change much with stacking, but the effect on the background is very obvious, and of course this allows fainter parts to emerge from the noise. 

It's also great to be back in the game after a lousy winter weather-wise. We now seem to have passed directly from winter to summer...

Martin