Triplet in Ursa Major

[wimvb]

Up here in the North, we've enjoyed almost a full week of clear nights, unfortunately coinciding with a nearly full moon. After collecting Ha data for M82, I pointed my scope at a patch of sky in the belly of the bear. The intention was to see if this area would be worthwhile to image when the moon is out of the way. While this triplet doesn't have the details of the Leo triplet, it's surrounded by quite a bunch of fuzzies. Furthermore it seems rarely imaged; a Google search didn't turn up much. This is only 17 minutes of Luminance data under moonlight (setting behind a neighbour's house).

(Click on the images to see larger versions)

Here are some details:

NGC 3613

• Magnitude: 12
• Size: 3.9 x 1.9 arcminutes
• Distance: 96 Mly

NGC 3619

• Magnitude: 13
• Size: 2.7 x 2.3 arcminutes
• Distance: 91 Mly

NGC 3625

• Magnitude: 13
• Size: 2 x 0.6 arcminutes
• Distance: 89 Mly

Imaging details:

• SW 150PDS on AZ-EQ6, guided with ST80 and PHD
• ASI 174MM-Cool at -30 C
• 50 x 20 s L-subs at unity gain, old master dark, flats, no bias
• Processed and platesolved in PixInsight.

If the weather allows, I'll do an Arnie on this one ("I'll be back"), and collect a few hours of lrgb-data.

[Demonperformer]

Definitely looks as if it might be worth some time. It's always nice to see something new being done.

[wimvb]

20 minutes ago, Demonperformer said:

Definitely looks as if it might be worth some time. It's always nice to see something new being done.

My thoughts also. It will be my last project this season. Fortunately the target is always reasonably high up in the sky, so I'm not limited to galaxy season. But it's at zenith now, ideal for good data.

[gorann]

Interesting project - look foreward to see what you make of it even it will be after the summer

[wimvb]

6 minutes ago, gorann said:

Interesting project - look foreward to see what you make of it even it will be after the summer

If it's after the summer, it will be from a darker site. We'll be moving late this summer.

 

[gorann]

Congratulations Wim to your new astro life! And congratulate you wife in agreeing to such a good decision! Obviously she can see that life will be so much better outside an orange area, for many reasons, not the least that her hubby will be so much more satisfied with his nocturnal life.

[MikeODay]

Very nice image Wim and best of luck with the new move.

[wimvb]

6 hours ago, MikeODay said:

Very nice image Wim and best of luck with the new move.

Thanks Mike.

[Rodd]

After I read "a weeks worth of clear, dark nights"  I had to go outside and scream for a while.  Looks like a nice collection of galaxies.  

Rodd

[wimvb]

2 hours ago, Rodd said:

After I read "a weeks worth of clear, dark nights"  I had to go outside and scream for a while.  Looks like a nice collection of galaxies.  

Rodd

Well, almost a week. But definitely not dark; the moon was nearly full. And just to put you at ease: from mid April until mid/end August, AP is a no go up here, because we'll lose astro darkness.

And the snow hasn't melted yet, but today it was raining. We're definitely not spoiled with dark and clear nights.

[Rodd]

2 hours ago, wimvb said:

Well, almost a week. But definitely not dark; the moon was nearly full. And just to put you at ease: from mid April until mid/end August, AP is a no go up here, because we'll lose astro darkness.

And the snow hasn't melted yet, but today it was raining. We're definitely not spoiled with dark and clear nights.

Must be nice in mid Winter though--20 hour nights.....not sure how far north you are.  20 hours is a LONG night!

[Demonperformer]

2 hours ago, Rodd said:

.not sure how far north you are

"Location: Sweden (59.47° North)" ... so 59.47°?

[wimvb]

7 hours ago, Rodd said:

Must be nice in mid Winter though--20 hour nights.....not sure how far north you are.  20 hours is a LONG night!

I wish. During winter, we've had very few clear nights, as has all of Northern  Europe. Thanks to global warming, it has become more cloudy in this part of the world.

And as for hours of darkness: on the date of the vernal equinox, day and night are exactly equal in length (12 hrs, sunrise and sunset), all over the globe. After that,  days get longer and nights shorter on the northern hemisphere. The farther north you go, the faster this happens. At the moment, astronomical darkness is less than 5 hours for me. Seven days from now, it will be 4 hours. And then it will take only two more weeks untill it's gone alltogether until August. To make up for it, during winter we get about 13 hours of astro darkness.

The very edges of the hourglass indicate sunset (left) and sunrise (right). The black zones indicate astro datkness.

Living this far north has both advantages and disadvantages. The cold makes it possible for people like Göran (@gorann) to get excellent results with an uncooled dslr. It also causes cables to become so stiff they might break. That's why I have started replacing plastic power cables with silicone cables. And nobody knows how lubricants and grease behave at temperatures below -15 C. The cold also keeps air moisture down, giving crisp, cold and very clear nights, especially just before spring.

If you live farther north than 65 degrees, not all mounts will allow you to align in latitude without a wedge. The notorious bending bolts syndrome of Skywatcher mounts is a real problem (and the main reason I bought the AZ-EQ6).

But still, I wouldn't want to move back to my native country (Netherlands), because "up here" it's still possible to get to a dark site without taking long trips. Light pollution is more localised than elsewhere in Europe. And life isn't just astrophotography.

Cheers,

[Rodd]

5 hours ago, wimvb said:

I wish. During winter, we've had very few clear nights, as has all of Northern  Europe. Thanks to global warming, it has become more cloudy in this part of the world.

And as for hours of darkness: on the date of the vernal equinox, day and night are exactly equal in length (12 hrs, sunrise and sunset), all over the globe. After that,  days get longer and nights shorter on the northern hemisphere. The farther north you go, the faster this happens. At the moment, astronomical darkness is less than 5 hours for me. Seven days from now, it will be 4 hours. And then it will take only two more weeks untill it's gone alltogether until August. To make up for it, during winter we get about 13 hours of astro darkness.

The very edges of the hourglass indicate sunset (left) and sunrise (right). The black zones indicate astro datkness.

Living this far north has both advantages and disadvantages. The cold makes it possible for people like Göran (@gorann) to get excellent results with an uncooled dslr. It also causes cables to become so stiff they might break. That's why I have started replacing plastic power cables with silicone cables. And nobody knows how lubricants and grease behave at temperatures below -15 C. The cold also keeps air moisture down, giving crisp, cold and very clear nights, especially just before spring.

If you live farther north than 65 degrees, not all mounts will allow you to align in latitude without a wedge. The notorious bending bolts syndrome of Skywatcher mounts is a real problem (and the main reason I bought the AZ-EQ6).

But still, I wouldn't want to move back to my native country (Netherlands), because "up here" it's still possible to get to a dark site without taking long trips. Light pollution is more localised than elsewhere in Europe. And life isn't just astrophotography.

Cheers,

According to the "chart". at 41 degree north (me), I get 15 hours of darkness on the  Winter Solstice.  The difference between Nautical Dark and Astro Dark is about 45 min or so?  So I get as much darkness as you?

Rodd

[wimvb]

According to this site:

https://www.timeanddate.com/worldclock/sunearth.html?iso=20181221T2222

the difference in astrodarkness for you and me is about one hour at the winter solstice. The calendar I included in my previous post is only valid for 60 degrees North.