From Winter towards the Summer along the Milky Way

[Dom543]

I was fortunate to spend the past new moon in Hawaii Island and devote several nights to watch stars from one of the best locations on Earth. In addition, to compensate for the deprivations of the past few months, I also bought myself a used Samyang 24mm f1.4 ED manual focus camera lens. This thread is to document my first uses of this lens to take wide field views of object-rich sections of the Milky Way. Starting near wintery Orion, by 5 am in the morning (not of the same day) I ended up on the doorsteps of the summer.

Traditionally, wide field Milky Way views seem to be the domain if DSLR users. So there is not much example to go by in near-real time with the small 8mm sensor of a Lodestar. (All captures have been taken with a monochrome Lodestar x2.) As you will see, I haven't succeeded yet to establish my own Milky Way style either. Coming from nebulas, I still try to concentrate on the fainter objects and to suppress the "disturbing" cornucopia of stars. But in the course of a week, I may have made some progress helped by the fact that the summer Milky Way is more of a feature itself, than its winter arm. Any critique, suggestions and comments in the direction of establishing a more consistent near-real time Milky Way style, that is both aesthetically pleasing and analytically helpful, would be appreciated.

The thread also has two more side objectives. One is to show the usefulness of camera lenses in near-real time electronic astronomy. The second one is to demonstrate that, if one has the time and the patience, then multi-spectral captures with monochrome cameras are not only fully feasible but also offer some substantial benefits over the use of their one-shoot-color siblings. When I am saying this, I also want to emphasize, that I fully agree that for public outreach and broadcasting, when the audience demands instant pop-pop-pop fireworks, there is no substitute for the simplicity of OSC captures. If you look at the time stamps of my captures, you will notice that they were all taken after 11pm, when the crows have already safely departed.

For full disclosure, I admit that I am also posting the same images on CN. But I am composing the posts independently and the difference between the audiences and the cultures of SGL and CN seems to justify, or at least excuse, the double posting.

I am looking forward to hear your critiques, suggestions and comments.

Clear Skies!

--Dom

P.s. My internet connection is very unreliable. It may take some time to post all images or I may have to temporarily suspend posting, when the connection is too weak to upload images. I have also developed the habit of posting first and checking spelling later. Perfect spelling is of little use, if it gets erased by a blank "You are not connected to the internet" screen.

[Dom543]

Monoceros Molecular Cloud

I am starting with the section of the Milky Way that is just West of Orion and includes old time narrow-field favorites like the Rosette and Cone Nebulas. To get as much of the possibly unknown to me nebulosity visible, I pushed all sliders to their limits for the first capture. To me it looks like a grinning dinosaur running with a football. Below is a second, more subtle image, on which I also marked the catalog numbers of nebulae that I could identify. As you can see, the Rosette Nebula, that is usually considered a large object is merely a small size ball in this game of the giants of 24mm focal length optics.

The two images are merely different displays of the same data. A live mean stack of 3x30sec exposures with an H-alpha filter and an additional 2x30sec frames assigned to the green and blue channels. The latter are needed to make the stars white. The fist image is with linear DR mapping and the second one with x^0.25. The non-linear function suppresses the brightest elements, including the stars and gives more relative weight to fainter areas. The equipment used was the Samyang 24mm f1.4 ED lens stopped down to f2.0, a Baader 7nm H-alpha filter, a Lodestar x2 monochrome camera and StarlightLive 2.1 software.

The Rosette Nebula, and possibly also some other objects in the area do contain a sizable O-III component. But my prior experience is that it is virtually impossible to prevent the O-III signal from being overwhelmed by the much stronger H-alpha. So in this case I didn't even try to include the O-III component. maybe another time.

Clear Skies!  --Dom

[Dom543]

Cone Nebula and Surrounds

I cannot recall of ever seeing an image of the large piece of nebulosity that includes and surrounds the Cone Nebula and forms the head of the dinosaur. I couldn't find a separate catalog designation for the object either. To take a closer look of it, I captured it with a 85mm focal length lens and this is what I got.

I find quite pleasing its softly winding and curling shapes. Not at all what I would have expected from the head of a dinosaur... According to star maps, the area should also contain "Hubble's Variable Nebula". I am not sure, if it is visible on my capture or if it is in its dim variable stage and hence not recognizable.

Any additional info about this large object or about the Hubble Variable Nebula would be appreciated.

Clear Skies!  --Dom

[Dom543]

Western Carina Area

As in Hawaii and at the right time of the year, I was eager to capture this jewel laden part of the Southern skies, which cannot be seen from many other places in North America or Europe. In fact, I turned to this area on the very first night out with my new lens. I am only making these posts in the order as the areas are lined up along the Milky Way. Before getting into details, I am also posting the same image with some of the objects marked and labeled.

The technique of the capture is the same as for the Monoceros one. 3x10sec exposures with an H-alpha filter assigned to the red channel and 3x10sec frames assigned to the green and blue channels. The image is displayed with the x^0.25 option to keep in check the overwhelmingly bright Eta Carinae and let fainter objects also be seen.

As this was the first night of my use of this lens, I foolishly left it fully open. Not remembering my past experiences that taught me that my fingers are not sufficiently fairy-light to focus optics faster than f2.0. Inaccurate focusing resulted in the rocket shaped stars. Annoying to see it afterwards and not being able to go back and retake the image, especially that for this luminous area there was no need for the fastest possible optics. I could have easily used 20 sec exposures at f2.0. Anyway, the resulting question is if it is of any use at all to spend money on optics faster than f2.0. I don't know the answer. Some say that any lens is better to be stopped down a notch from its nominal max. On the other hand, I am able and like to use my 135mm f2.0 lens fully open. A side benefit of using lenses fully open in astronomy is the absence of diffraction spikes around bright stars. 8 or 9 bladed apertures don't make particularly nice diffraction patterns in my opinion. Any opinion or input welcome.

Clear Skies!  --Dom

[Dom543]

Carina Nebula

As I have been using the phrase "jewel-laden area", it is apt to also display at least the crown jewel of the Southern Milky Way. One advantage of these wide field captures is that one can see the full extent of the various objects.  The map provided by the image of the previous post made me aware that all my previous attempts captured only the central part of the Carina Nebula. So this time I reached again for the 85mm Pentax SMC Takumar to provide a full capture with a nice framing of this object.

For a change, this is, actually a dual spectrum narrowband image. 3x15 sec exposures with the H-alpha filter assigned to the red channel plus 3x15 sec exposures with the O-III filter assigned to the green and blue channels. All live mean-stacked together in StarlightLive 2.1. The central part around Eta Carinae contains a strong O-III component. I would love to see that displayed in its turquoise green. But, unfortunately, the addition of the equally strong red H-alpha component turns it  into the greys white that you see on the images. The witish core is better than an all red purely H-alpha image but I am still thinking about possible ways to get the center of this flower green and would appreciate any suggestions. By the way, to keep the very bright Eta in check, this image has also been displayed with the x^0.25 option.

Parts of the image look dirty noisy. It's, actually, not noise but the stars of the Milky Way. The narrowband filters strongly underweight the stars and emphasize the nebulosity but we are still in the middle of the Milky Way.

Clear Skies!  --Dom

[Astrojedi]

Great shots. Wide field provides such a different perspective. The Carina Nebula is pretty low even in Hawaii. Good work. 

[Paul81]

Wow, a terrific set of observations! The camera lens is a great tool to have for EAA! 

Glad to see multispectrum is helping yield some great results, looking forward to seeing more!

[Dom543]

Southern Cross Rising out of Kilauea

This was a unique and very time limited opportunity. So I jumped to grab it as my very first use of this lens. My hurry and lack of experience caused leaving the aperture fully open and the resulting inaccurate focusing and bullet like stars. But still, its better than to miss out on the opportunity.

The red glow of the lava lake in the crater of Kilauea is illuminating the fumes emitted by the volcano. The fumes, in turn, are blown by the wind in the direction of the rising Cross. There is no current active eruption of lava from that crater. What looks like an eruption on the image is just intense light blowing out the corresponding pixels of the sensor.

The capture has been taken from the Mauna Kea Visitor Information Station. The VIS is about 35 miles from the crater and at 9200 feet elevation, it is usually above the inversion layer. Volcano, being one of the rainiest places of the U.S. and only at 4000 feet, is usually under not only of the inversion layer but also of its own vog. Hence it is a rare opportunity to see it directly and clearly from the VIS. This, and the rapid rise of the Cross, explains my hurry and resulting mistakes.

There was an additional challenge, namely that stars, and my mount were moving, while the volcano insisted on staying put. They call it a divergence. And I needed to change filters and check and uncheck checkboxes of software between exposures to get colors out of my monochrome Lodestar. This was the one and only case this far, when I thought that a one-shot-color camera might have been better to have. I unplugged the mount but didn't know what settings would have been needed to stop StarlightLive being glued to the moving stars. (Any hints would be appreciated for the future.) And the cross and the volcano were visibly diverging towards opposite corners of even the 24mm lens's wide field. The best I could come up with was to take dozens of shots and training my fingers to move faster and faster, at the pace of the 0.25 sec exposures.  To make the long story short(er), I have dozens of captures with green and red volcanoes being separated and a few, like the one posted, where things worked out o.k. But I could really use the trick that stops StarlightLive from following the stars. Bits of faint star trails would be much preferable to bi-color glowing volcano trails...

By the way, I remember of seeing an image of the same volcano and stars above it posted on the CN DSLR forum about a year ago. It was from a fairly experienced and respected frequent poster. It was a montage of a static ground image (including the volcano and foreground terrain) merged in Photoshop with an image of the Milky Way. On this forum we cannot do that...

Clear Skies!  --Dom

[Dom543]

1 hour ago, Astrojedi said:

Great shots. Wide field provides such a different perspective. The Carina Nebula is pretty low even in Hawaii. Good work. 

Thank you Hiten!

You are right in both issues. Wide field perspectives are different and there is no reason for us near-real (time) people from staying out of that fun. A decent wide field lens can be had for less than a camera. And as my almost 50 years old Takumar shows, they have much longer staying power than cameras.

There is just one significant challenge involved. Frames with tiny stars are MUCH more difficult to stack accurately. This is not just an incrementality issue. We have to be immensely be grateful to Paul for his continued efforts to keep improving on the live stacking capability of LodestarLive/StarlightLive.

You are also right that the Carina Nebula is staying low even from Hawaii. But one thing that helps in that case is elevation. I forgot to say that the Carina captures were also taken from the MK VIS at 92oo feet elevation. The thinner air makes a noticeable difference. Yes, stars do still twinkle near the horizon but they twinkle much less than from sea level.

Most of the images that I am posting on this thread were taken from a backyard setup in Waikoloa at 1500 feet elevation on the leeward slopes of the island. But for objects in Carina, Crux and Centaurus it is worth the drive up to the VIS.

Clear Skies!  --Dom

[Martin Meredith]

Some wonderful wide views of these objects which really help to set them in context; a lot to read and digest. As Paul says, the multispectral approach is really yielding dividends and lends itself to inventiveness. Love the T Rex and I can't help but see a pair of lipstick stains at the lower part of the Carina Nebula.

I got as far as your question about Hubble's Variable Nebula and I think it is visible horizontally aligned with the 'D' of the word "Date" on the caption, and just a touch right of centre. The star field looks right, as is the fan shape with the widest part pointing north east.

[edit] The largest bright nebula designation I could find in that area is LBN 929 (540x120 arcmin) but that seems to be the structure that contains everything in your first image. Then centred nearly on Hubble's VN there is LBN 922 (180x60). SkySafari appears to label the whole dinosaur's head as the Cone Nebula with the same NGC number as the open cluster itself.

Martin

[Dom543]

Northern Scorpius Area

Somewhere between tiny Crux and boring Lupus the Milky Way makes the transition  from a skimpy winter road to become the highway to sparkling summer fun. And my absolute favorite area of the sky is just after this turn right in Scorpius. I love colors and nowhere in the universe are colors as striking and abundant as in the neighborhood of aging Antares. Before I get carried away, here is a copy of the above capture with some of the highlights marked.

This is a plain and simple RGB capture. The first one of this breed on this tread. 3x30sec red + 3x30sec green + 3x30sec blue all live mean-stacked together in StarlighLive 2.1. The 30 secs are not really needed, 10 or 15 sec would be plenty sufficient for this bright and shiny area at f2.0.

I intentionally framed the field so that Saturn would be locked out.  But now I regret it. I could have just cropped it out, if it disturbed. Too late now but a little bit of an orangey light at the top of the field filters in and that's from Saturn.

Not much else to say. Except that spring is here in the sky, at least for those, who sty up until 4 am in the morning. And summer is just around the corner...

Clear Skies!  --Dom

[Dom543]

O.k., last call. I am getting kicked out of Banjy's Paradise and cut off the internet. I promised to take you to the doorstep of summer. So please check back, more is to follow... 

Dark Skies!  --Dom

[laudropb]

Very nice set of images and very well presented.

[Ain Soph Aur]

Awesome post Dom!

[HiloDon]

Excellent presentation, Dom.  Shows what can be done with simple wide FOV setups and inexpensive optics, and the benefit of Paul's software.  

Don

[RobertI]

Fantastic post Dom, some amazing widefield views. Still absorbing and enjoying the images. Enjoy Hawaii you lucky devil.  

[Dom543]

Thank you for the positive comments and likes.

I apologize for some of the rambling posts and winding, ill formulated sentences from yesterday. I was sitting in a bar, the only place , where I could find internet connection and was constantly distracted by other patrons, who wanted to be nice to me. They thought that I was on the computer in a bar because I was lonely or had some other problem and wanted to cheer me up. The were genuinely nice and I couldn't tell them to let me alone. Very different than in Seattle. Over there they might not even serve you a beer in some bars, unless you order it on a computer or at least on some electronic device. They think that there is something wrong with you, if you are not on a computer or some electronic device...

Anyway, let me try to post the remaining photos before the connection goes away.

--Dom

[Dom543]

Antares - Rho Ophiuchi Area

This is the central part of the Northern Scorpius area of the last photo and the most photogenic area of the sky in my opinion. Before I post the annotated version of this image, I include my capture of the same region from last year.

This was made with a Lodestar x2 color and was by personal favorite from last year. The base capture stack was enriched with frames taken a blue and then an H-alpha filter. So it had the elements of a multispectral approach. But things were much more difficult to implement before Paul separated the three color channels and made them directly accessible. It is also interesting to compare the size of the stars. I believe that that reflects the difference between the mono and color sensor. Both captures were made with the same 85mm Takumar lens. I was pleased to see how nicely M4 was resolved despite of the very wide field. I am not good at astrometry but believe that tis is about a 5x4 degree field.

Finally, here is the annotated version.

Clear Skies!  --Dom

[Dom543]

Pipe Nebula and Friends

This is also a straight RGB capture: 3x15sec red + 3x15sec green + 3x15sec blue. This is probably the most "Milky Wayish" image in this sequence and the type that for, some reason, is not often seen on the "video astronomy" forums. I badly wanted to get to this area last summer but something always prevented me. Once, I remember, it was the smoke from forest fires all around in Washington State.

I have not made an annotated version of this image as it is easy to give a simple description and almost impossible to give a more detailed description of the objects in this field.  The big black thing is the Pipe Nebula, the magnitude 3 star above it is Theta-Ophiuchi. The larger pink smear in the lower left corner is the Lagoon Nebula M8 (that is usually too big to fit in its entity in one's telescope field) and the smaller pink dot over it is M20, the Trifid Nebula. This is the easy part. Then there are dozens of individually cataloged dark nebulae in the area above the Pipe and Theta-Oph. That is an intriguing area and I would have loved to take a closer look at it with the 85mm lens. But as you can see it on the time stamp, it got to 5 am and the Japanese tour busses were already congregating to greet the sunrise. So the closer exploration of that cavernous area will have to wait for another new moon. Dark nebulas require dark skies...

As the Lagoon and the Trifid are in Sagittarius and Sagittarius equates to summer, I have fulfilled my promise and took you to the doorstep of the summer.

Thank you for bearing with me. Clear Skies!

--Dom

[MrOD]

I think i do not even know the word in english language that could describe what i feel after this wonderful journey. Thank You very much for sharing this.

[PeterW]

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

[Paul73]

Great work Dom!! an advert for Ellectronic Astonomy (& Hawaii).

I really enjoyed the detailed write up.

Paul

[Astrojedi]

51 minutes 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,

Have you seen this Sky Survey? http://media.skysurvey.org/openzoom.html

Hiten

[PeterW]

Yes and wikisky. But hard to get just the hydrogen emission to stand out on its own. Best to just image only that.

 

peter

[Dom543]

8 hours ago, Paul73 said:

Great work Dom!! an advert for Ellectronic Astonomy (& Hawaii).

I really enjoyed the detailed write up.

Paul

Thank you Paul!

I was more thinking this as a series of thank you cards to your close neighbor (on the membership list), Paul81 for all his work that gave us LodestarLive/StarlightLive. And also to our fellow forum member Nytecam, who discovered and demonstrated the potential of the Lodestar for electronic observational astronomy.

Cheers!   --Dom