Tag Archives: galaxies

It’s a great time for CT residents to view the night sky

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If you are interested in astronomy, there will be some excellent opportunities for viewing and photographing the night sky in the coming months. Spring (March – May) is known as “galaxy season” to amateur astronomers, with a greater number of galaxies visible in the night sky than any other time of year.

Many amateur astronomers take advantage of this time to observe and photograph these amazing objects.

Galaxies are huge swirling masses of stars, cosmic gas and dust held together by gravity. With the recent deployment of the James Webb telescope, we are learning much more about their age and origins. There are estimated to be billions of galaxies in the universe, each containing billions of stars. They are present in a variety of shapes and sizes, and typically span light years across. The galaxies we can observe are millions of light years away, and it is really amazing that we can see them at all at that distance, even with a telescope.

The Andromeda Galaxy is the closest galaxy to our Milky Way, at a distance of 2.5 million light years away.

Most of us have seen the amazing photographs of galaxies taken with the James Webb telescope, either in the news, on-line or in astronomy magazines. However, you may not know that a photograph taken from your own back yard with only amateur equipment can also reveal some excellent detail of deep sky objects, including the glowing stars present within the massive spiral arms of galaxies, and the regions of new star formation or “nebulosity” interwoven between them.

Unlike other forms of photography, astrophotography involves taking a series of long exposures or videos, and then processing them digitally afterward with a technique known as image “stacking.” This results in a much brighter composite final image with greater detail than would otherwise be possible. After capturing and saving the desired images on a laptop computer, image stacking can be done with a variety of different astronomy-specific software applications, and additional software can be used to give the photos their final touches.

When taking photos of galaxies or any other deep sky objects, selection of the right equipment is key. As far as the telescope itself is concerned, telescopes with shorter focal lengths and a wider field of view (such as a small refractor or reflector telescope) are best for beginners to learn on. As you gain expertise, telescopes with bigger apertures, longer focal lengths and a narrower field of view can also be used.

Cameras used for astrophotography have extremely sensitive optical sensors, specialized to gather dim light from distant objects, and are usually electronically cooled to reduce optical noise. A standard 35mm camera can also be used instead of an astronomy camera, but modifications may need to be made to achieve good results. The camera is typically connected to the back of a telescope and to a laptop computer, where images can be downloaded and viewed on the computer screen while capturing them. In addition, one of the most important pieces of equipment needed for astrophotography is a sturdy equatorial telescope mount, which automatically tracks the movement of the stars to allow in-focus images without star trails.

What is the best way to learn astrophotography? The most important thing you can do is to join a local amateur astronomy club, where you can go to observing events (aka “star parties”) and meet other like-minded amateur astronomers. Most clubs have members with a wide range of expertise and interests, and you can learn a lot in a very short time. I belong to the Thames Amateur Astronomical Society in southeast Connecticut, but there are also others in the state including the Astronomical Society of Greater Hartford and the Astronomical Society of New Haven. No matter where you are located, there is likely to be an amateur astronomy club in your area.

When learning this hobby there is also a lot of information available from various on-line forums such as the “Cloudy Nights” forum, where you can find others with the same equipment you have and post your questions. Other on-line resources that I have found useful for learning this hobby include web sites or you-tube channels for Heavenly Backyard Astronomy, Astroforum, Star Stuff, Martin’s Astrophotography, AstroBackyard and Late Night Astronomy. Last, I have found Astronomy Magazine to be a great source of information as it provides equipment reviews, good articles, and tips on what to look for in the night sky each month.

Whether you are an experienced or beginning amateur astronomer, I encourage you to try your hand at astrophotography, and galaxy season is a great time for that. Starting out in this hobby can be expensive, and can have a large learning curve, especially for those with little or no background in photography or astronomy. However, if you if you have the time and patience to learn, it can be a very rewarding and enjoyable hobby.

John Natale is an amateur astronomer and resident of East Haddam. For additional information on amateur astronomy or astrophotography, he can be contacted at [email protected].

 

 

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The Webb Telescope Fires Back Jaw-Dropping New Galaxy Images

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The James Webb Space Telescope—a $10 billion observatory that sees beyond human vision and into the infrared—has sent back more images of galaxies in unprecedented resolution.

The images are the subject of a special issue of journal The Astrophysical Journal Letters this week that features a whopping 21 research papers that together tease-out new details about the beginnings of star formation and how that affects the evolution of huge galaxies.

The images were all taken using JWST’s MIRI (Mid-Infrared Instrument), a camera and a spectrograph that sees light in the mid-infrared region of the electromagnetic spectrum and takes better-than-Hubble wide-field astrophotography images.

JWST’s ability to see in infrared means it can look through dust clouds that block visible light reaching telescopes like Hubble. However, as this image (above) of the “Phantom Galaxy” shows, JWST is also proving a huge step forward when compared to its predecessor, the infrared-capable Spitzer Space Telescope, which was live between 2003 and 2020. The galaxy is about 32 million light-years distant in the constellation of Pisces.

“Since Spitzer was retired, we haven’t had much access to the mid-infrared spectrum, but JWST is incredible,” said Karin Sandstrom, Associate Professor of Physics at University of California San Diego and co-author of one of the new papers, on the interstellar medium (the gas and dust between galaxies). Spitzer had a mirror that was 0.8 meters whereas JWST’s mirror is 6.5 meters. “It’s a huge telescope and it has amazing instruments,” said Sandstrom. “I’ve been waiting a very long time for this.”

The new details displayed in these images are spectacular and scientifically important.

NGC 1433, pictured above, is a barred spiral galaxy with a bright core surrounded by two rings that are each producing stars. JWST’s infrared images—translated into visible color using filters—include bubbles of gas where stars have released energy into their surrounding environment in their birth-throes.

NGC 1433 is about 46 million light-years distant in the southern hemisphere constellation of Horologium and known as a Seyfert galaxy because of its active nuclei.

It’s hoped that images like this can help researchers map the structure of molecular clouds that stars form from as well as the gas surrounding baby stars to get to the bottom of how a galaxy forms new stars.

“Areas which are completely dark in Hubble imaging light up in exquisite detail in these new infrared images, allowing us to study how the dust in the interstellar medium has absorbed the light from forming stars and emitted it back out in the infrared, illuminating an intricate network of gas and dust,” said Sandstrom.

Another image published this week—though actually the first spiral galaxy JWST looked at when its science phase began in mid-2022—is of NGC 7496. A spiral galaxy about 24 million light-years away in the constellation of Grus, it’s stuffed with star clusters and dust lanes.

In this image, above, its spiral arms are flecked with huge bubbles that are the result of baby stars releasing energy.

In this image (below) of NGC 1365, a double-barred spiral galaxy about 56 million light-years away in the constellation Fornax, clumps of dust and gas in the interstellar medium have absorbed the light from forming stars and emitted it back out in the infrared. For the first time astronomers can see what’s going on inside the galaxy.

All of these stunning images are part of one of the early “Webb Treasury” studies. The long-running Physics at High Angular resolution in Nearby GalaxieS (PHANGS) survey has been building a dataset that investigates the links between stars and cold molecular gas in spiral galaxies, most recently using Hubble, but also the ALMA radio observatory and the Very Large Telescope, both in Chile.

The international research team is now using JWST to survey the stars, star clusters, and dust that lie within 19 nearby galaxies. Five have now taken place—four of which feature here—with 14 more to come.

Wishing you clear skies and wide eyes.

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The New ‘Smart Telescope’ That Lets You Stay Indoors While It Shows You Spectacular Images

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It’s a telescope, but not as we know it. Meet the eVscope eQuinox 2, a new so-called “smart telescope” unveiled this week at CES in Las Vegas that adds planets to the roster of what it can image in the night sky.

The annual tech show is mostly known for huge TVs, drones and electric cars, so what is a diminutive telescope doing in the halls of the Sands Hotel?

The eVscope eQuinox 2 is not like most telescopes you will have seen before, probably gathering dust in a friend’s spare bedroom. The eVscope eQuinox 2 has no eyepiece. You cannot look at the night sky through this telescope. Instead of your own eyes collecting the light from distant galaxies, nebula and star clusters those photons go directly to a Sony IMX347 sensor.

The eVscope eQuinox 2 is all about astrophotography, not stargazing—and you can sit indoors while it does its thing and just wait for its images to be delivered to your smartphone.

It’s modelled by French company Unistellar on professional telescopes that are found the world over, usually on mountain tops, which collect light using the giant mirrors before focusing those photos on an image sensor. Hey presto, you get image date of galaxies and anything else astronomers care to point these behemoths at. This is also essentially how space telescopes like Hubble and Webb work.

The follow-up to 2021’s eVscope eQuinox, this second-generation version is not like those professional telescopes, but it is way more slick. A 4.5-inch/114mm reflector telescope with a focal length of 450mm, focal ratio of f/4 and 50x magnification, the eVscope eQuinox 2 weighs 9kg, has a motorized alt-azimuth mount, an 11-hour rechargeable battery and 64GB of storage. It produces 6.2 megapixel images in JPEG or RAW formats. They’re easy to share and easy to post-process, if that’s your thing, but the whole point of the eVscope eQuinox 2 is that it’s autonomous.

You literally just put this smart telescope in your backyard—or even on your balcony in a light-polluted environment—and it gets to work plate-solving, comparing the stars it can see in the sky with a database on its on-board computer. Within a few minutes it’s ready to use.

Using an smartphone app it’s possible to choose from a list of deep sky targets you want the eVscope eQuinox 2 to observe. Each object in its database comes with baked-in settings for exposure times and ISO, so all you really have to do is wait (though you can tinker with the settings if you want).

In fact, you can actually leave the telescope outside and go sit indoors because the live image it produces is shown on the app and continually refreshed. It depends on what you are looking at, but for faint objects such as nebulae, the longer you leave the telescope staring at it, the better the finished image will be. That’s because it’s taking an image every 30 seconds or so, and stacking it on top of the last one, thus producing a cleaner and brighter image as time passes. It’s these algorithms and machine learning that are the secret sauce inside the eVscope eQuinox 2.

I’ve used the original eVscope eQuinox extensively—adoring it mostly for its skill at completely bypassing light pollution—and this new version looks interesting. At $2,499 it’s the company’s most affordable model yet. It now has a new sensor and a slightly wider field of view (34×47 arc minutes). The latter means it can fit larger objects into its field of view, chiefly the Andromeda galaxy and the Moon (though until a firmware update arrives it won’t be primed to take images of our only natural satellite).

However, what’s really interesting about the eVscope eQuinox 2 is a much-anticipated new ability to study and image planets. In stark contrast to the long exposure images it uses to find objects, the incredibly bright orbs of Jupiter, Mars and Saturn are snapped using something called “lucky imaging”. Another technique used by huge ground-based telescopes, this is when astrophotographers continually snap away at an object in the night sky hoping that Earth’s turbulent atmosphere will, just for a split second, settle enough for them for the image to be perfectly exposed, sharp and without any distortion.

“The eQuinox 2 smart telescope puts incredible power in the hands of the general public and inspires a new generation of urban stargazers who can now enjoy an amazing voyage to the universe from their balcony and within minutes. Thanks to its unique technologies and its smart design choices, we are putting space within reach from anywhere, even from light-polluted cities,” said Laurent Marfisi, co-founder and CEO of Unistellar. “Now, novice stargazers and amateur astronomers can enjoy stunning clarity, color, and hard to see details like the striking colors of the Dumbbell Nebula.”

The Unistellar eVscope eQuinox 2 can be pre-ordered now, with shipping expected from mid-February 2023.

Wishing you clear skies and wide eyes

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