How dark are your summer nights?

[wimvb]

Yesterday I was enjoying the beautiful night after a very hot day. Just before midnight (daylight saving time), the only star I could see was Vega. Just past 1 am, the supposedly darkest time of night, I could only see the summer triangle, Vega, Altair, and Deneb. With binoculars (see my signature for details), I could see a few more stars in that area of the sky. To the north, I had the skyglow from the sun, just below the horizon. I live away from the light dome of Stockholm, and my winter sky darkness is about 20.7 mag/arcsecs2.

I'm curious, just how dark is the sky where you live, this time of year?

Edited June 25, 2020 by wimvb

[DaveS]

Only have nautical dark at the mo, but the last few nights by 12.30 or so (BST) the Milky Way was quite strong with the Cygnus Rift and other structure clearly visible pretty much to the southern horizon, even though it was barely 40 degrees high at the time. Light pollution mad suggests 21.66, but I have my doubts.

[Victor Boesen]

This is a timelapse I shot a couple years ago dated 03/06 - 2018 and the last shot from the timelapse is taken about 01:50AM. It's quite a good indication of how bright the sky is from Copenhagen at 55 deg north.

Victor

[Guest]

Only nautical dark here too but being right on the south coast get a reasonable amount of it. As a reference it is nautically dark here tonight from 23:25 - 3:08 and we are only just past the solstice.

Last night was particularly clear and I could probably see over 100 stars with the naked eye at 1am (and I don't have the naked eyes I used to!). That is from my Bortle 5 skies looking south into Bortle 4

Certainly dark enough for 3-4 hours of deep sky imaging.

 

Edited June 25, 2020 by Guest

[RobertI]

Reasonably dark here, last night at around midnight I could see the milky way and was observing some DSO's with my 6" Newt - managed to see the Veil with a UHCE filter. I'm at 52° N.

[F15Rules]

I live on the edge of the Lincolnshire Wolds, the skies are classed as Bortle 4, and the nearest large towns are Boston, due south, c17 miles away, and Skegness almost due east, about 15 miles.

Compared to West Leicestershire, 12m west of Leicester, where I moved here from over 3 years ago, and within 20 m of Coventry, Birmingham, Tamworth etc all around (Bortle 5/6),the skies here are much better, especially the lower in the sky you go, the darker it seems compared to the orange dome of the Midlands.

But at the moment, it really doesn't get nearly as dark, even here, as in the autumn/winter. I was out for an hour last night (until my RA drive batteries died!) from 11pm til midnight. After packing the scope away I just looked up for a few minutes, and although I could see many more stars than at 11pm, I couldn't see the Milky Way (normally this shows structure and lanes overhead), and couldn't see all the main Little Plough (Ursa Minor) asterism stars with the naked eye.

However, I don't think last night's poor visibility was just down to summer short nights: the transparency wasn't great - although the seeing was very good. This often happens, I find: the best observing of planets, moon, double stars etc is on nights of good seeing, while the best views of clusters, nebulae, globulars and other deep sky objects are often when the stars really twinkle, and the atmosphere feels really "clean" - such as after rain for example.

Dave

Edited June 25, 2020 by F15Rules
Typos

[Nigeyboy]

This is a good site for seeing when Astronimical / nautical night etc begins / ends for your location.

Not looking good in Derby until Mid-July!!

 

[Victor Boesen]

8 minutes ago, Nigeyboy said:

This is a good site for seeing when Astronimical / nautical night etc begins / ends for your location.

Not looking good in Derby until Mid-July!!

 

Very helpful website! Thanks for sharing;)

Doesn't look good here either...

Edited June 25, 2020 by Victor Boesen

[Nigeyboy]

Wow Victor! Your not even getting Astro Twilight this time of year!!

[Victor Boesen]

Just now, Nigeyboy said:

Wow Victor! Your not even getting Astro Twilight this time of year!!

Sadly no... My grandparents live a little further south but I don't visit them as often as I'd like to. Guess I'm stuck with low elevation (for now) planet observing and noctilucent clouds;)

[DaveS]

According to the tables I get Astro Dark back at 17th July, but only for 38 mins. Still 3 weeks away  

[Nigeyboy]

16 minutes ago, Victor Boesen said:

Sadly no... My grandparents live a little further south but I don't visit them as often as I'd like to. Guess I'm stuck with low elevation (for now) planet observing and noctilucent clouds;)

On the plus side, I guess your winter nights are longer than ours further South!!

[alacant]

19 hours ago, wimvb said:

how dark is the sky where you live

Alicante, 38º N

Hi Wim, everyone

I'd forgotten the thing about astro darkness being latitude dependent. Here we get around 5 hours, The main enemy at this time of year being the heat and the haze, the latter depending on wind direction. Luckily this year we're free of the other variable, the tourists. Apart from those who come, telescope in hand, for the clear nights of course!

Cheers.

Edited June 26, 2020 by alacant

[kev]

scarbro ( yorkshire uk).   it doesnt. always blue kn horizon at this time of year.  its a major difference from being in letchworth (herts,uk)

[Pixies]

Edinburgh:

Last night I reckon the lowest magnitude I could see was 2.8. the summer triangle was OK, the 2 head stars of Draco were just there, but I couldn't make out the keystone asterism at all. I had to use binoculars and my 10x60 finder to locate M13.

Going to take a break for a few weeks, I think.

[DaveS]

Bride Valley

 

[John]

It does get dark here but not for very long. 2-3 hours of observing and the light starts to infuse the eastern sky.

Over the last few nights I've been able to see the milky way faintly running through Cygnus somewhere between midnight and 1:00 am. Had some decent views of the Veil Nebula with 100mm - 130mm scopes, with the help of the O-III filter of course.

Still, its only going to get better now we are past the solstice and observing the deep sky in shorts is quite nice

[Tenor Viol]

I think I check and for here (53N) nautical twilight ends about midnight and resumes about 01.30 - so about 90 minutes of 'reasonable' darkness, but there's always a glow to the north

 

[wimvb]

I just took a picture that shows the sky, looking West, at abt 23.30 (11.30 pm) local time. South is to the left, North to the right.

It's bright enough to read, if it wasn't for all those ... mosquitoes. The foreground looks brighter irl, but the sky matches about what I see.

And this is how sky darkness is for me throughout the year. As I 've said before, no astronomy up here during the months that don't have an "r" in their name.

Edited June 25, 2020 by wimvb

[Captain Scarlet]

I took an SQM-L darkness reading last night, at 51.4 degrees North, of 19.01 at around 1245, very close to mid-summer. That is basically as dark as it ever gets here (near London,UK) even in deepest winter. I’ve just posted elsewhere in this section my data and reasoning why, but basically in areas of moderate-high light pollution, loss of Astro darkness is “not a thing”.

M

[tooth_dr]

Very interesting thread @wimvb you really have very little darkness for 3-4 months.

These are my figures at 54oN.  I still did take this 1200s (F2.8) image on the 21st June.  It would take a keen imager to stay up and gather just a few minutes per night at this time of year though! The north/west never gets really dark now here.

 

 

[wimvb]

2 minutes ago, tooth_dr said:

Very interesting thread @wimvb you really have very little darkness for 3-4 months.

We are compensated during winter with 12 hours of darkness.

4 minutes ago, tooth_dr said:

I still did take this 1200s (F2.8) image on the 21st June.

Very nice image. Is that a single exposure of 1200 s?

[tooth_dr]

29 minutes ago, wimvb said:

We are compensated during winter with 12 hours of darkness.

Very nice image. Is that a single exposure of 1200 s?

Yes it’s a single 20 minute exposure from my epsilon.  I love winter too, we get some darkness. Nothing better then pulling up into the drive way after work and opening the obsy and starting imaging before dinner 🤣

[psistarsigh]

Bort. 7 or 8 Denver suburban sky. Can make out major constellations and polar align lol.  A lot of NB. So jealous of some of your skies!  

[Louis D]

Bortle 5/6/7 skies depending on the direction any time of the year since I'm right on the edge of farm country.  However, summer skies are lighter than winter mostly due to swamp-like humidity levels at night.  We are often at 98% humidity most of the night which gives a slight mistiness to the air that helps to reflect light pollution further into the darker parts of the sky.  I'll see haze around stars or the moon and think I've got equipment dewing until I look up naked eye and see a glow around bright objects.  To add insult to injury, it can stay over 90°F until after midnight as well, so I have to run a box fan across me perpendicular to my observing direction to avoid dripping sweat on my equipment and to blow away mosquitoes.

Here's my yearly nighttime chart from that website mentioned above, with the radix on the summer solstice:

It gets fully dark year round for at least 6.5 hours, but it means staying up much later on work nights to access it in the summer than in the winter.  Between that and the oppressive heat, humidity, and mosquitoes, I tend to do much less observing in the summer than in winter.  Our winters tend to be mild, dry, and bug free.  However, the atmosphere is much less stable than in the summer, so planetary observing does suffer.