Astronomy Allsorts

[Size9Hex]

Another mixed bag of notes from the last couple of sessions. As always, I hope they're of interest or at least make for a nice read!

Tricky Doubles

I was experimenting with the 10 inch Doc on Saturday, with and without a homemade 3 inch off-axis mask. All observations at 180x. Overall, I'd say the mask was of benefit, with a less noisy view outweighing the loss in aperture. The standard 2 inch aperture that comes with the scope seemed worse than no mask. That said, from various attempts on Tegmen in the last month, I think the good seeing had more of an effect than any mask. If the seeing hadn't been good, I'd have packed up. The haze was robbing the sky of 1.5 naked eye magnitudes!

Capella showed three diffraction rings (with the mask) which were nearly but not entirely complete. This is the first time I've really looked at diffraction rings, so I can't offer a knowledgable assessment...

Tegmen (Cancer). Mag 5/6/6 triple at 5.3" and 1.1". Got all three, but might not have detected the 1.1" if I wasn't looking for it. Stoked to get this after 3 or 4 recent attempts. It was the seeing more than the mask that made the difference, but the mask did help.

STF 644 (Auriga). Mag 6/6 at 1.7". Attractive colour mismatch which I think helps the detection.

15 Lyncis. Mag 4/5 at 0.7". Interesting one. I didn't detect it, but I did initially detect that the star was elongated in a consistent direction. Eventually, I realised that the elongation was consistent only when the star was in the same area of the eyepiece. I wonder if I was detecting a visual defect on the mirror or eyepiece.

12 Lyncis. Neat little triple. Mag 4/6/7 at 8.7" and 1.9". Not as tricky as the others.

I'm really happy with this effort. I'm never sure that I've collimated the scope perfectly, but maybe detecting these doubles is an indication of a reasonable job. I wondered if 180x wasn't pushing the scope particularly hard either, so maybe there's further improvement to be had.

Hubble Deep Field

Clearer skies on Monday. I hopped via 76 Uma to star TYC 4162-0021-1 which I think is more or less on target for the Hubble Deep Field. Wasn't expecting to see much, but it's such a phenomenal moment in the history of astronomy that I just wanted to see where it was and contemplate it. Spotted a mag 13.7 star in the field which is as faint as I've knowingly seen.

While in the wider general area of Ursa Major and Draco, I spotted a few galaxies:

NGC 4521, mag 12.9. Tricky!
NGC 4605, mag 10.2

And inside the UMa saucepan:

NGC 3888, mag 12.1. Also tricky. 140M light years away which blew my sense of perspective. Perhaps the most distant thing I've seen.
NGC 3610, mag 10.8
NGC 3613, mag 10.8
NGC 3619, mag 12.5
NGC 3982, mag 11.8
NGC 3998, mag 10.5

Wrong Side of the Moon

Trying hard to avoid saturating the forum reports with Pink Floyd references! 10 inch Dob again. Spotted a dark patch and bright spot on the dark side of the moon (gaarrrr....!). I'm guessing Grimaldi and Aristarchus. Neat to see these features in reflected light from the Earth.

While there, I spotted the HD 30483 (mag 7) near the dark limb about to be occulted. Utterly, utterly stunning. It was there and then gone in an undetectably quick instant.

Mare Humboldtianum and the region beyond detected near the bright limb. I think these are visitors from the far side of the moon when it wobbles in the right direction towards us.

A few other bits and bobs from the Lunar 100 list, which I'm really enjoying as a means of exploring the moon. Craters Armstrong, Collins and Aldrin were tricky, with Collins the hardest of the three. The moon was just above my neighbours roof which may not have been helping.

Binocular DSOs

Stoked to get M81 (easier than expected now that it's high in the sky) and particularly M82 (tricky).

A nice quick foray into some familar and unfamiliar clusters too: M35, 36, 37, 38 (all revealing aspects of interest that are unavailable in the scope!), Double Cluster, Caldwell 10, Stock 2, Trumpler 2 and Melotte 111. The binos give great context to these targets.

Amalthea

Had an unsuccessful crack at a fifth moon on Jupiter in the 10 inch. You never know unless you try!

[StarSapling]

Excellent report.

 

[laudropb]

Very nice report. I really enjoyed the read.

[cotterless45]

Excellent report ! Closing down a bit of aperture certainly works, well spotted,

Nick.

[Paul73]

Enjoyable read. Thank you.

I've noted a couple of your targets for my planned multi star fest tomorrow. I've already got Nick's target list from SGLXI. So it should be an enjoyable evening.

Paul

[Size9Hex]

1 hour ago, Paul73 said:

Enjoyable read. Thank you.

I've noted a couple of your targets for my planned multi star fest tomorrow. I've already got Nick's target list from SGLXI. So it should be an enjoyable evening.

Paul

Thanks Paul. Hope it's a good enjoyable session for you tomorrow. Fingers crossed for good conditions!

[Piero]

Fantastic report, Paul!  

I never masked the aperture of my telescopes. Certainly not the 60! But not even the 114, and I didn't have a chance to try it on the 200mm. Your finding are interesting though, and I hope to give a try next time I fly back! (Already booked three flights!  )

Your sentence "Trying hard to avoid saturating the forum reports with Pink Floyd references!"  made me smile!  

 

[Size9Hex]

On 15/03/2016 at 23:25, Piero said:

Fantastic report, Paul!  

I never masked the aperture of my telescopes. Certainly not the 60! But not even the 114, and I didn't have a chance to try it on the 200mm. Your finding are interesting though, and I hope to give a try next time I fly back! (Already booked three flights!  )

Your sentence "Trying hard to avoid saturating the forum reports with Pink Floyd references!"  made me smile!  

 

Thanks Piero. Sorry couldn't resist following your own Pink Floyd reference! I've found the mask that comes with the 250px to be so small that it has made the view worse (but it's good for checking up on seeing conditions against a bright star). The larger homemade mask has been mainly worse than the full aperture, except on the tricky doubles where has helped a little by removing glare and particularly the diffraction of the struts on the secondary mirror. The length of time I've been experimenting with it is admitedly not long though. It'll be interesting to hear from you if you experiment with it too.

[Piero]

40 minutes ago, Size9Hex said:

Thanks Piero. Sorry couldn't resist following your own Pink Floyd reference! I've found the mask that comes with the 250px to be so small that it has made the view worse (but it's good for checking up on seeing conditions against a bright star). The larger homemade mask has been mainly worse than the full aperture, except on the tricky doubles where has helped a little by removing glare and particularly the diffraction of the struts on the secondary mirror. The length of time I've been experimenting with it is admitedly not long though. It'll be interesting to hear from you if you experiment with it too.

There was a time in the past when I listened to Pink Floyd every day..  

I will try to do my best at testing this, although I will have "counted days" in Italy. In the first two coming trips there will be full Moon too (I could not avoid those days unfortunately!). The positive thing is that I will go for Mars and Saturn with the delos + PM2.5x or Bresser SA 2x . Hopefully the sky will be clear!