Comet C/2020 F3 NEOWISE
A Bright Comet in the Dawn
We have a bright comet in the dawn sky for a few days. Comet C/2020 F3 NEOWISE has brightened rapidly over the past few weeks, now about 1st magnitude it can just be seen against the glow of dawn.
I took along Hodepodge to serve as a tracking mount for the TV-76mm scope and a couple cameras to do some comet shooting. The Canon 6D would go with the small ‘scope, the EOS-M5 with a tripod for wide angle shots.
Driving up Waikoloa road I was troubled by a bank of clouds in the Waimea saddle, thus I elected to head for the Humuʻula saddle instead. I ended up in the lava fields along the Mauna Loa access road. The view was perfect, and I had just enough time to get the mount and camera setup as the comet rose.
Continue reading “A Bright Comet in the Dawn”Mango Season
Mango season is here! We have been eating ripe mangoes for a few weeks now. Mango on ceral, mango smoothies, and a whole dryer load packed up and sent to my mango loving mother in Oregon.
For some reason the fruit on our big tree seems to have come from two different sets, with the first fruit ripening almost a month ago and the majority of the fruit just coming on now after a lull.
Not a huge crop this year, but plenty for our needs. We will be eating mango for a while longer.
Happy 4th of July
The Veil in Hydrogen Alpha
To allow a wider field of view requires changing optics. In this case putting away the TV-76mm telescope and mounting a vintage Nikkor 180mm f/2.8 ED camera lens.
The Nikkor 180mm is a classic lens, once a favorite of professional film photographers for news and portrait work. Now the lens is out of date, not autofocus, or image stabilized, a bit of very good optics left behind by technology.
Of course, autofocus or image stabilization are useless for astrophotography. With a simple adapter the lens can be mounted to a modern system and used as a fully manual lens in an application where the excellent optical quality can still be appreciated.
The Hercules Cluster
The Hercules Cluster is one of the best known, and as you would expect, one of the most beautiful clusters to be seen in a small telescope. Also known as M13 this is a rich globular cluster with several hundred thousand stars it lies about 25,000 light years away in the constellation Hercules.
The cluster is always worth stopping by, whatever size telescope you are using. If I am using a larger ‘scope I might try to locate the small galaxy NGC6207 located about ½° to the northeast (upper left). If I am using an even larger ‘scope like my 18″ I can also try for the challenging IC4617 that lies halfway between NGC6207 and the cluster.
The image here is a luminance image only, taken through a filter that blocks IR and allows the remainder of the visible spectrum through to the detector. To get allow capture of the fainter stars while not overexposing the core a range of exposures from 10 seconds to five minutes were combined to create the image seen here…
Lava Fountain
Rho Ophiuchi Region in Monochrome
The Rho Ophiuchi region is a confused mass of gas and dust just above Antares and the head of Scorpio. This extensive nebula complex is far larger than the single frame shown here, extending far to the east into Sagittarius.
Rho Ophiuchi itself is the triple star seen here at the top center of the image, at the center of a bright reflection nebula. The double at lower center is Iota Scorpii and the star Al Niyat is on the right side. Also notable are the dark clouds of dust and gas that block the light of the stars and nebula behind creating black voids in the starfield.
This area is quite colorful, with both the blues of reflection nebulae and the reds of emission nebulae. I have gathered some color data but need more before assembling a proper color image of this region.
Leo Galaxies
Just killing some time while I wait for the Milky Way to rise and to shoot my primary targets for the night. Maybe some galaxies in Leo? There are a lot to choose from, but I am setup for wide field using the TV-76mm with only 389mm of focal length. Too wide to make individual galaxies interesting, maybe a galaxy group?
The group around M95/M96/M105 should be good, it fits in the field nicely. Just shoot for about an hour before moving on the the main targets of the night. With any luck those wisps of evening clouds hanging about will go away as well.
There are a number of nice groupings of galaxies in Leo… The Leo Trio (M65, M66, and NGC3628), and this group around M95 and M96, and a number of fainter galaxy pairs and clusters to chose from.
The Eagle in Hydrogen Alpha
I have been processing more images from this last week. This one is another classic nebula, the Eagle. The nebula, also known as M16 or NGC 6611 can be found in thick regions of of our galactic core towards the constellation of Serpens.
The eponymous eagle can be seen near the center of the brightest region, a structure of darker material likely held together by the gravity of objects inside it. In this case those objects would be forming stars, or protostars, the result of the dust and gas being drawn together under the influence of gravity.
I have a full set of color filters, once I have had fun re-doing many of these classic nebulae in hydrogen alpha I will probably begin doing full color versions. Color takes a lot more exposure time and much more processing. There are techniques to add H-alpha data to an RGB image to get more definition in the nebula structure, something I have not done and should probably figure out.
