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Binocular DSOs and a test of darkness

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OK... It cleared (sort of). We've had rain with high wind pretty much solid for the last 2 or 3 days and everything was deeply wet. As I popped my head out at 10 for a gander I could see the stars (sort of) - there was soup and lots of it as the obviously very humidity level was just killing it. I checked again at 11pm , 12pm... and 1am. It had gotten much better. I was pretty much done from the day's activities however I didn't want to completely waste a night... So binoculars it was taking them to the nearby part away from any local light sources and took my iPhone for taking the SQM measurement using the Dark Sky Meter with my iPhone

It looked nice and dark. Several measurements were taken around different areas and noting any brightening above the horizon:

West: Very dark indeed visually which is not surprising as there are no real populated places for quite a distance (approx 35 miles) with hills anyway and zero light pollution from the visible horizon. Pointed somewhere between 30 and 45 degrees with he iPhone and the measurement was 20.8 to 20.9 taken 3 times.

North: Very little brightening on the immediate visible horizon. Major city is approx 20 miles distance. Again nice and dark just a touch less than West. Very good! SQM taken multiple times around 40 degrees was always around 20.7 to 20.8.

East: Major city is approx 15 miles away however there's a big hill between me and that and so the first 10 degrees realistically is out of view. I can see some local brightening from Belper's lights but it's well controlled and not much LP going above the line of houses. SQM reading taken multiple times was around 20.5 taken at approx 40 - 45 degrees

South - This is the worst by far visually - at least the first 20 degrees going over the bulk of Belper and some clouds in the distance are quite lit up possibly by Derby which is only 9 miles away. Still, it quites quite rapidly dark and from 30 degrees is not bad at all. At least there's no horrible orange glow that I used to experience from Oxford. SQM readings taken multiple times around 35 to 45 degrees yielded in 20.2 to 20.4.

Taken at the zenith the reading was always around 20.6 to 20.7

OK, so visually what does this translate to? The transparency was so-so - certainly not completely clear although some areas were better than others. Looking at Ursa Minor the 7 stars to mag 5.0 were easy to spot at 60 degrees Alt. After some time and dark adaption and using a breathing technique I was able to distinguish the 5.7 mag star (HR 6034) and becoming more obvious with averted vision, 19 Umi was also seen.

To the North-West, The constellation Auriga was shining brilliantly even though it was now quite low down. As to was Lyra in the NE, also low down. Extinction from LP was no-where near as a problem unless it was directly to the South.

So, with the binoculars I had a bit of a tour around the sky: Double Cluster although low down looked amazing with the bins. I thought that I could just M13 was very bright and large. M57 I could just make out a faint small smudge.

Directly above me was Ursa Major - M51 was really bright the two cores were still obvious with the bins which surprised me rather than seeing one extended fuzz-patch. M101 was really easy - amazing how large this is!!! Although this was giving me (literally) a pain in the neck trying to view it with craning the neck so much with the bins so I didn't spend too much time on it.

The Milky Way realistically is too low to view at the moment naked eye but with the binoculars showed up nicely scanning around this area. Particularly the region around Auriga which is a riot. I didn't have any atlas with me though and forgot the positions of M35 to M38 so I didn't spot these. I'd like to see another night also if these are visible naked eye.

I wrapped up the session as it quite brutally cold and getting very late. It was nice to get out though albeit for a short session and mainly testing the sky out.

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Dave we must have had the same thoughts last night. At about 11pm it was crystal clear with all the 7 stars in Ursa Minor visible + a few more around the area. I took out the Apollo 15x70 binos and just toured the night sky - no star atlas - M81, M82, M101, M51, M63, M13, M92, M38, M36, M37,  M3, M53, M64,M65, M66, NGC2903, M44, M67,M35 + NGC2158, M46, M47, M93 and M1. I screwed in a Lumicon UHC + Astromomik O-III into the binos  and tried to view the Flaming Star Neb (not successful). However, the Rosette Neb was very clear.

Sometimes an hour or so with binos can be very rewarding.

I was interested that you were able to take a dark sky reading with your iPhone I wonder if this app is available on the Android system?


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Hi Mark.  I'm not sure that it's available for Android but worth checking....  Good to hear you got out as well for a decent session!   Hopefully I'll have another opportunity soon to see if I can catch the Rosette with the bins or the 120ST from the park as it's much better situated than my house for viewing.

Ursa Minor is a great judge for NELM it has several stars from mag 5 to 6.  19 Umi is mag 5.5 I forgot to mention...  I need to see if I can get 24 Umi (mag 5.8) although its proximity to the much brighter 4.3 mag Delta Umi (Yildan) may make it a tougher target.

I think the nebulae around Cassiopeia are perhaps too low at the moment.  While in the region of the Double Cluster I headed over to the Heart & Soul nebulae which I've seen clear the brighter portions of these before on a very transparent night without any filter using the 120ST.  However, it was unsuccessful this time.  I've only seen the Flaming Star nebula when positioned much higher up.

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I enjoyed your write up Dave, thanks.
After seeing a post earlier my Neil - @Littleguy80 - who mentioned the sky meter on the iphone I searched for similar for Android, I didn't find anything. If anyone has more success I'd be pleased to hear.

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