The days are hot, the nights are short and rainy, in other words: summer is here.
I don’t have particular plans at the moment. I’m still doing spectroscopy on the semi-cloudy nights with mixed results and I hope to maybe image the Trifid Nebula if the opportunity is there. No target list, no time pressure, just enjoying the nice weather.
I do hope the Helix Nebula will work this year as last two years the weather didn’t allow any imaging during the short time it’s visible. Fingers crossed.
Here is my first summer object, the Cygnus Wall, about 3 hours with the Antlia ALP-T processed in HOO.
I remember watching the Iris Nebula for the first time with my 224MC camera in EAA mode. I still think this is one of the most fascinating objects in space. I tried imaging it twice before, last year. The first round I wasted a good 6 hours of data by using the wrong filter. The second time I forgot to check the weather reports and ignored a wind warning causing most of my subs to be ruined.
So here’s about 9 hours or so on this magnificent object. The combination of blue core, dark dust and gold speckled stars is just something else.
In other news, I upgraded my coma corrector to the TS GPU and while doing some tests yesterday I immediately noticed the difference in quality, so this is my last image with my baader mpcc.
I’ve been reading about brown dwarfs lately. So yes, it’s time for some deep, faint stuff again.
These are so called substellar objects, they have more mass than planetary gas giants but less mass than regular main sequence stars. These objects have not enough mass and density to generate hydrogen fusion and the end result is basically a “failed star”.
These stars come in various subclasses. There are the M dwarfs (also called red dwarfs) and then the cooler L, T and finally Y dwarfs. The Y class are so cool that they are probably the hardest objects to detect, JWST even detected Y stars with negative temperatures.
I decided to focus on the L stars and started to compile lists with potential candidates to photograph.Making that list was interesting in itself because the unique feature of brown dwarfs is that they emit most of their light in the near infrared. This means that determining the magnitude of the objects was a bit more difficult than usual.
This near infrared also has other consequences. It means we can’t use our traditional broadband UV/IR cut filters. So I decided in the end to do it as rough as possible: no filters, no guiding, no dithering and just see what happens.
The first one is 2MASS J18071593+5015316 in Hercules. This is an L1 class brown dwarf about 47 light years away. Visually it’s located not too far from the galaxy cluster abell.
The second is 2MASS J12043036+3212595 in Ursa Major. This is an L0 class brown dwarf about 65 light years away. The big galaxy in the corner of the image is NGC4062.
The last one is LSPM J1438+6408 in Draco. This is another L0 class brown dwarf about 55 light years away. This is probably the brightest one, I could see it after a few frames sitting close to the faint galaxy PGC52318.
Summer is upon us. I was up late and was amazed at seeing the summer triangle and even Cassiopeia in crisp clear conditions. Unfortunately there was a bit of a breeze but that couldn’t stop me from getting almost 3 hours integration time on this beautiful edge-on galaxy in Coma Berenices.
I’ll wait a few weeks now for Cygnus to be high enough to start some projects on that area. In the meantime I hope to have some clear skies to focus on star spectra.
I don’t really like postprocessing that much but it’s a necessary part of astrophotography. I usually try to keep it light. I don’t stretch the image too much, I keep the noise reduction at minimum and whenever possible I try to be as gentle as I can with saturation to keep natural colors alive.
Yesterday I had a try at the Pinwheel Galaxy. It’s not a difficult target, it’s fairly bright, only Andromeda, Triangulum and Bodes are brighter, I believe. But after my meridian flip I noticed some big streaks of light on the image. I think those are reflections of Alkaid, a bright hot star in Ursa Major, outside of the field of view but reflecting through my imaging train. So I had to really carefully process this away, which I don’t like, but anyway. Here’s the result.
And here are the streaks. I’ll need to have another look at my setup to limit those reflections in the future.
We are nearing that time of the year when galaxy season is ending and the milky way is not high enough to start imaging nebulae. I had another clear night and decided to shoot a galaxy regardless of the near full moon.
Here is M81 or Bode’s Galaxy, 12 million light-years away in Ursa Major.
April is always known for erratic weather patterns but this year is extra special. We went from 27 degrees to -1 in just a couple of days and now we seem to be getting back to warmer weather. This week I had one opportunity but things were difficult. I had a very obvious pinching effect going on with my scope which is caused by the cold and results in triangle looking stars. I don’t think I really solved it completely but managed to get about 2 hours on globular cluster M3.
I like these clusters a lot. They look like these dreamy unreal balls of stars and their age and origin are mysterious.
I have a lot of projects going on and have been updating my rig this year to invest more time in exoplanet transits and spectroscopy and have some widefield imaging gear on the way too. I hope to log some results soon.
With all those small, faint ARP galaxies and quasars, one would almost forget that the visually most spectacular ARP galaxy is right under our nose under the name of ARP85, better known as the Whirlpool Galaxy or Messier 51.
The string of nights with high cirrus clouds continue, but there are clear moments and I managed to get 3 hours of integration time on this target and pull out a lot of detail in post-processing.
Interesting also to compare with some of my older attempts to see how I’m evolving in this hobby. Below two images were my first attemps with a planetary camera and no guiding or complicated post-processing. I couldn’t believe I was imaging colliding galaxies from my backyard. I still can’t believe sometimes.
Let’s see if we can bag a few more galaxies before we’re back to planets, nebulae and other peculiarities.
It’s been mostly cloudy lately so I did some spring cleaning. Tuning the mount, cleaning the mirrors, fixing my focuser. While doing that I accidentaly chipped a part of my secondary mirror by gently dropping it on our kitchen island. Not good. Needless to say I was a bit anxious for my first imaging session.
The problem lately is that we have a lot of high cirrus clouds, so while it looks okay to image there is actually too much noise to get some proper data. I decided to try it anyway and went for TON618, an iconic quasar located near Canes Venatici and Coma Berenices. I got about 4 hours of data and happy to report no signs of weird reflections due to my mirror issue.
TON618 is huge. It’s one of the brightest objects in our universe, it hosts an ultramassive black hole which for a long time was considered the largest ever detected and it’s located over 18 billion light years away.
There is much more to see in this image, like the faint galaxy (UGC7604 right next to the quasar) and NGC4414, the beautiful spiral in the lower right corner. I checked my image in Aladin and discovered a bunch more distant galaxies and faint quasars.
We are supposed to get some proper clear skies later this week so hopefully I can capture some ARP galaxies before the end of galaxy season.
If you descent deeper into the rabbit hole of astronomy you will soon bump into the work of Fritz Zwicky. This absolute legend did a lot of pioneering work on supernovae, black holes, lensing, dark matter and lots of other topics. He’s also famous for this quote: “Astronomers are spherical bastards. No matter how you look at them they are just bastards.” He was a special one.
One important contribution to science was his proposal of the idea of dark matter (dunkle Materie). He came up with this theory while observing the Coma galaxy cluster and the discrepancy between the speed of movement of the galaxies and the total mass of the cluster. Something unseen, he concluded, was keeping the galaxies from flying apart. Now this was in the 1930s and it would be only years later when Vera Rubin confirmed the existence of this “dark mass”. Fascinating stuff.
Anyway – lots of reasons to try to image this cluster.
I don’t think I really managed to capture it as well as the Perseus galaxy cluster in the fall, but I still like the end result. There are over 1000 galaxies in this cluster at a distance of over 320 million light years. And for once I managed to shoot the whole night without a single mount issue.
