From Winter towards the Summer along the Milky Way

[Dom543]

9 hours ago, PeterW said:

Dom, would be great to get a "full sky" halpha map. I observe these nebulae "visually" and it is hard to get any overview images to compare my observations with. Most imagers only take images of small bits, but never wider....  Where there are lots of unlabelled wispy bits... As you see. Maybe do it with a 50mm lens to get a bit bigger image scale.

 

thanks

peterw

Peter,

I had something similar, but infinitely less ambitious, in mind. To have a map of the feature rich areas of the Milky Way as a guide for myself on what to look at next. And to organize the many small popular favorites seen so often and put them into their real context.

Unfortunately, my time here in Hawaii is limited and I also have real assignments to accomplish during this time, not just to have astro fun. So the best I can try to do during this trip is to get a couple of more exploratory images.

But as you disclosed your interest in H-II regions, I have a questions to you. I believe that I see a faint hydrogen region between M8 and the heel of the Pipe nebula. I marked it below but you may want to check it on the original image, where the yellow markings are not interfering. Do you know of any H-II region at that location? It seems to be centered around a slightly brighter star of the Milky Way. I couldn't find any reference but I don't have many resources with me here. Not even a decent internet connection...

Thank you,  --Dom

 

[PeterW]

Hmm, nothing in interstellarum, which has a lot of sharpless plotted. If you're in that region then do a wide angle shot of zeta ophiuchus with an halpha filter on... Sharpless 27.

being able to grab some southerly shots is very helpful as I can't usually access this area of sky due to summer twilight!

you want to image the Milky Way and a reasonable amount beyond it as there are some nice HII regions in north Cepheus for instance,

 

great work

 

peter

[Martin Meredith]

Looks to be the right position/size for Sharpless 2-22 at 17h 55 4.7 -24° 50 28.3?

This is the info I have:

60'x40', brightness class 4 (1=brightest, 6=faintest), form irregular, structure neutral, star count 5, colour class 3 (= brighter on red plate); also known as LBN 14

Martin

[Dom543]

Thank you Martin and Peter!

When I get back to the area, I will take a closer look with the 300mm lens. This kind of exploration and discovery with optics of different magnification and FOV is, actually quite a bit of fun. When using  camera lenses, I usually have the 300mm and 180mm Nikkors mounted permanently but have to switch the 135mm and the 24mm, which are competing for the same adapter.

Clear Skies!  --Dom

 

[MrOD]

Dom one question.
How do You mount filters when You are using lens? In front of it or rather some slim drawer or filter wheel between lens and camera?

[Dom543]

MrOD,

I use standard Baader 2" filters and slide them into a Teleskop-Service filter drawer system. This is mounted between the lens and the camera. When using the multispectral feature of StarlightLive, it is nice to have a convenient way to change filters. Plus most of my fast lens have an entry aperture larger than 2". They say that filter mounted between the lens and the camera can cause reflections. This is the probable cause of the reflection halo around Antares. As I observed this only around magnitude 1 Antares, I can live with it.

If my skimpy bandwidth allows me to upload it, then I include a photo of the adapter that I have made. Its components are (1) Nikon female bayonet scavenged from a Nikon to canon adapter, (2) Spacer and support cut from aluminum L-profile bar from nearby hardware store, (3) TS filter drawer system (on the photo a filter slider is halfway drawn out), (4) TS camera rotator with male T-thread. The parts are bolted together with #4 bolts (~M2.3). I can directly screw on this my SX-825 and rotate it or I screw on a 1.25" eyepiece holder and slide in the Lodestar. All my lenses are Nikon and to reach infinity focus with the adaptor must be less then 28.5mm thick, which it is. (The Lodestar is about 5mm more tolerant, as it has less back focus)

Clear Skies!  --Dom

[Dom543]

Barnard's Loop

This is a little bit of add-on to the winter end of this thread before the winter and Orion are entirely gone.

Samyang 24mm lens at f2.0 and Lodestar x2 mono with LodestarLive 2.1 multispectral. The entire loop fits but barely in the field of the Lodestar with the 24mm lens. For comparison further below I include a capture from last year with a 35mm lens and Lodestar x2 color. The present image is made of 3x30sec exposures with a 7nm H-alpha filter assigned to the red channel plus 2x30secexposures assigned to the green and blue channels. Tha latter are needed to make the stars white and the nebulae of more realistic color. The challenge of this large and rather faint object is the presence of the overly bright M42 in the field. (As you can see, last year I carefully excluded M42 from the smaller field.) I tried to deal with this extreme variation by using the x^0.25 option in StarlightLive. This non-linear dynamic range mapping is proving itself useful to suppress the brightest areas and enhance the fainter areas of a capture.

The same with a few labels to help orientation.

This is the capture from last year with a 35mm lens and Lodestar x2 color camera. This is pure H-alpha, hence there are much fewer stars. The stars that are white correspond to blown out pixels. A year ago there wasn't x^0.25 option or multispectral in LodestarLive.

Clear Skies!  --Dom

[Dom543]

Orion the Snowman

To me our friend Orion looks more like a half-melted potbellied snowman than the handsome hunter for whom the Greek godesses were competing. He even has a wide grin, eyes and an ear on his round head made with fading charcoal...

Anyway, this is what I see with a Samyang 14mm camera lens, a Lodestar x2 mono camera, a 7nm H-alpha filter and StarlightLive v.3.0. 3x90sec exposeures with the Ha filter assigned to the red cannel plus 2x45sec exposures assigned to the green and blue channels. I used the non-linear x^0,25 HDR option in StarlightLive to reduce the brighness of M42 and enhance the fainter Hydrogen nebulosity. One challenge with these large fields is to find a 5 minute period, when no little cloud is floating through the field somewhere. It took me three nights...

The head is Sh2-264, also called the Angelfish or Meissa Nebula. The belly in Sh2-276 Barnard's Loop. 

For those, who don't believe that this is Orion, I include a reduced copy of the capture with the familiar outlines.

Say goodbye to our friend, spring is here and he will melt away soon for the year.

Clear Skies!  --Dom

[PeterW]

We believe you, some of us have spotted them with my our own eyes, some of the biggest nebulae up there. You need clear (and usually) cool nights to get the best view. Nice shots....

 

peter