The Age of Origin - Star Clusters

After taking a look at galaxies and then nebulae, it is time now to see some of the star clusters that I have photographed in the last few months with my Celestron Origin telescope.

I'll start off with the closest of the bunch, the wonderful Pleiades (also known as The Seven Sisters and Messier 45):

At at distance of just over 400 light years, the Pleiades is the second closest star cluster to Earth. It is easily seen in the night sky and is a part of many sky myths from across the globe. The cluster looks good the the unaided eye, as well as through binoculars and telescopes. 

It is an open star cluster. Open clusters typically have a few hundred to a few thousand stars. 

In addition to the many stars seen here, there is also a prominent reflection nebula--essentially dust that is illuminated by the light of the stars in the cluster. When I was a kid it was widely thought that the dust was left over from the formation of the cluster, but now we know that it is unrelated to it.

The cluster's apparent diameter is too large for me to capture all of it in a single image, so I will return to build a mosaic hopefully later this year. 

The open star cluster known as Messier 46 is ten times farther away than the Pleiades:

This cluster also features an added treat. Just on the left edge of the cluster is a small planetary nebula. Like the dust in the Pleiades it is unrelated to the cluster itself, but makes for an added bonus when observing in this part of the sky.

Further out is the famous Double Cluster in Perseus:

The two clusters are NGC 866 (at top) and NGC 884 (lower middle) lie some 7,500 light years from Earth.

At a distance of just 6,000 light years, Messier 4 in Scorpius is clearly an all together different type of star cluster:

It is a globular star cluster. These clusters contain hundreds of thousands of stars. Many of these clusters are the remnant cores of small galaxies that have been/are being consumed by our Milky Way galaxy. 

Messier 4 can be easily seen with binoculars just west of the red supergiant star Antares, in the heart of Scorpius.

Further out lies Messier 13, the Great Globular Cluster in Hercules:

Messier 13 is about 22,000 light years from Earth. M13 is the finest globular star cluster in the northern sky. The Southern Hemisphere has some finer ones, but they are too far south for me to be able to photograph them.

Also in this image (near the lower left) is NGC 6207, a spiral galaxy located some 30 million light years from our Milky Way galaxy. 

Finally, here's another globular star cluster, though it is so far away it hardly even looks like one.

 NGC 2419 is sometimes called the Intergalactic Wanderer, though it does indeed orbit the center of the Milky Way galaxy. It is located 275,000 light years from Earth. That puts is 12.5 times farther away than M13!

It has been unusually cloudy of late, but I will be posting more astrophotos in the near future. 

The Age of Origin - Nebulae

Here's the second of my three initial posts looking at some of my astrophotograpy from the Celestron Origin smart telescope. Today, its nebulae. Star clusters will be next.

Let's start off with a popular target from the Northern Hemisphere's winter skies: the Horsehead Nebula. 

That's the Horsehead Nebula, also known as Barnard 33, at center. It's a dark cloud that's in front of a red cloud of hydrogen gas that lies some 1,300 light years from Earth. To the left of it is a blue-white reflection nebula known as NGC 2023. In the upper left is the Flame Nebula (NGC 2024) and immediately to the right of that is the star known as Alnitak. Alnitak is the left-most star of Orion's Belt.  

Almost three degrees to the east of the Horsehead is Messier 78, an amazing complex of both dark and reflection nebulae located at about the same distance from Earth as the Horsehead Nebula.

M78 is at center and NGC 2071 to the left, but clearly they are part of the same region of space. Both have stars embedded within clouds of gas and dust.

The Rosette Nebula in Monoceros is much larger than the Origin's field of view but I shot a series of overlapping images to create this mosaic. 

This is a region of star formation that has an open star cluster (NGC 2244) at center that's surrounded by a ring of glowing hydrogen gas that's leftover from its formation.

No visit to the winter skies would be complete without a look at Messier 42, the Great Nebula in Orion. 

M42 is almost too bright, but I think that this image captures it nicely. You can see clouds of dark nebulae, blue reflection nebulae and red hydrogen gas. 

Planetary nebulae are created when a Sun-like star that has evolved into a red giant sheds its outer layers into space. 

Messier 27, the Apple Core Nebula is one of the brighter planetary nebulae:

It's located about 1,200 light years from Earth in the direction of the constellation of Vulpecula, the Fox. 

Unlike any of the previous images in this post, this image was taken using the nebula filter that Celestron sells to go along with the Origin. The remaining images here also make use of the nebula filter, including the Helix Nebula below:

The Helix another planetary nebula and is about half as far away as M27, which is why it is larger in the sky. 

Great targets for summer evenings include Messier 16, the famous Eagle Nebula:

At the center of the Eagle nebula lies the famous "Pillars of Creation" that has been photographed by both the Hubble and Webb Space Telescopes. The pillar-shaped dark features at center within this nebula are a part of this nebula which is creating a new cluster of stars.

At the end of their lives massive stars explode as creating supernovae. A supernova is an expanding cloud of star guts. The Veil Nebula is a part of the Cygnus Loop supernova remnant. The western part of the Veil shown here is also sometimes called the Witch's Broom Nebula:

The supernova that created the Veil Nebula exploded between ten and twenty thousand years ago.

A star that has not yet exploded, but someday will, is Wolf-Rayet 136, a massive star that has shed some of its gas creating what is known as the Crescent Nebula (NGC 6888):

That's WR 136 at center. It lies some 5,000 light years from Earth and when it explodes it will be bright enough to be seen in the daytime. Alas, we don't expect this to happen anytime soon.

Finally, here's perhaps my favorite nebula, Messier 8, the Lagoon Nebula in Sagittarius:

Like M42 above, if you are observing in an area free from light pollution the Lagoon Nebula is just visible to the eye. Through a telescope its a grayish cloud associated with an open star cluster. 

There's a famous image of the Lagoon Nebula that was one of the first color images of space. It taken before I was born with the 200-inch Hale Telescope at Palomar Observatory. You can see it on my old Palomar Skies blog from when I worked at the observatory.
 

The Age of Origin - Galaxies

It's no secret that I am a big fan of smart telescopes, so I was quite interested when Celestron introduced their new Origin smart telescope last year. I was able to get one in November and I thought I would use this post to show off some of the images that I have taken with it. This post will focus just on images of galaxies.

Most of the images here are less than an hour of observing time and have minimal post processing by me, showing off how impressive the Origin is at capturing the cosmos. 

One of my first targets was Messier 31, the Andromeda Galaxy. 

Two of its satellite galaxies are visible. M32 on the right and M110 in the upper left. 

The Origin has a wider field of view than the Unistellar telescopes that I have been using, but its not big enough to catch all of M31. Later this year I'll try a mosaic to try to capture the full view.

Also located within the constellation of Andromeda is the edge-on spiral galaxy NGC 891. At a distance of 32 million light years its 14.5 times farther away than M31, so it looks somewhat lonely in space.

NGC 891 has a nice dust lane that cuts across it and may be somewhat similar to our own Milky Way galaxy.

NGC 253, the Sculptor Galaxy, is located 12 million light years away and is a nice target:

Located at about the same distance, but in different part of the sky is a great pair of galaxies Messier 82 and Messier 81 in Ursa Major.

That's M82 on the left. M82 is classified as a "starburst" galaxy due to a period of rapid star formation, which is likely the result gravitational interactions with M81 at right.

Two galaxies at once is nice, but how about three?

 Here are the three galaxies of the Leo Triplet.

That's NGC 3628 (the Hamburger Galaxy) at left, Messier 66 in the lower right and Messier 65 is above that. At a distance of 42 million light years M65 is the furthest of the three, while NGC 3628 is the closest with a distance of "only" 35 million light years.

Looking further out into space and you can take in many galaxies at once. Here's a portion of the Virgo Cluster of galaxies known as Markarian's Chain.

The view is dominated by two giant elliptical galaxies: Messier 84 near the top right and Messier 86 near the center. Respectively they are 66 and 57 million light years away. Numerous other galaxies of the Virgo Cluster can be seen as well.

I have yet to shoot even more distant galaxy clusters, so I'll end with two galaxies that just look good.

 

That's Messier 51, the Whirlpool Galaxy, at right. Its spiral arms spin out to the left to a smaller galaxy, NGC 5195. The two galaxies are interacting and located some 28 and 25 million light years away respectively. M51 was the first galaxy discovered to have a spiral shape is a beautiful target.

My next post will show off some of the nebulae I have photographed using the Celestron Origin. 

 

The Sun and the Moon in Motion and Jupiter too!

 This fall I have been on a sabbatical from my teaching and focusing on lots and lots of backyard astronomy. 

One of my early observing goals was to capture the Sun every day for an extended period to show its rotation. I was able to image it every day for 17 consecutive days - from August 20th through September 5th. I then aligned the images to produce this animation showing the Sun's rotation:

Another interesting way to look at this is to add the images together, which produces this:

This nicely shows that sunspots occur in parallel stripes on either side of the Sun's equator.

I have also been able to shoot the Moon on consecutive nights to show its changing phases and the effect of lunar libration (a kind of tilting and rocking). Here's how the Moon looked from October 7th through the 15th, as it went from a waxing crescent to nearly full:

You should be able to see that the Moon looks to be somewhat growing in size - not just the amount illuminated by the Sun, but larger. This is because the Moon's orbit is not a perfect circle and over the nights I shot these the Moon was moving towards Earth.

And then after a few nights of clouds I was able to capture the Moon again from October 18th through the 27th, showing it moving through its waning phases:

Again, I think you can also see here that the Moon appears to be getting smaller. That was because it was moving away from Earth in its orbit.

I don't usually have the opportunity to stay up late (or get up early) enough to shoot the waning phases, so this was a treat.

I had another stretch of clear nights again in November and I was able to capture the Moon from November 6th through the 14th as it moved from a waxing crescent to full.

Finally, here's Jupiter and its moon Europa as they looked the night of December 14th.

This is about an hour and 20 minutes of motion showing Jupiter's Great Red Spot rotating out of view to the right, along with other cloud features in Jupiter's atmosphere. Europa is the spot of light to the left of Jupiter.

Disco Sunspots!

 Back in October I posted about using a disco ball to observe a solar eclipse. It turns out that you can also use a disco ball to safely observe sunspots too. Here's how I did so earlier today.

Really all you need is a disco ball, a place to secure it in the sunlight and a shadowed area to project the image of the Sun. Here I have my disco ball sitting on a tripod for a Unistellar telescope. I aligned the disco ball so that it reflected an image of the Sun into my house and nearly 70 feet down a dark hallway on to a sheet of white paper. Here's the result:

It's not a great image, but you should notice a definite gray smudge-like area on the projected image of the Sun. That's a big sunspot that is visible on the Sun today. I also imaged the Sun with a Unistellar Odyssey Pro telescope and solar filter. I got this image which I rotated to match the orientation of the projected image above.

As you can see, that's the same sunspot group in both images. This is another confirmation that a disco ball is an excellent tool for safely observing the Sun.

Jupiter's Moons: Himalia, Elara and Pasiphae Too

It's no secret that I like to use my Unistellar telescopes to track down obscure things and to create animations of them moving in the sky. Back in August I managed to track down Saturn's faint moon Phoebe (on my blog here). 

Now that Jupiter is in opposition its time once again for me to take a look at it and some of its family of moons. The four Galilean moons are bright and easy to see with any optical magnification - even binoculars will work if you can hold them steady enough. 

Here's a shot of them taken in late October when Jupiter was also near enough to a background star that was almost as bright as one of the moons.

Jupiter has 96 (!) known natural satellites, but most people only ever see the four pictured above. Back in 2021 (when there were only 80 known moons of Jupiter) I first blogged about trying to extend my view to include Jupiter's moon Himalia. I found it, but wasn't very happy with my results, so I revisited finding that moon again last year (on my blog here) and now that I have just seen it again, I suppose that it has become an annual thing for me.

The animated gif below is from two images taken 58 minutes apart on 9 November 2023. Himalia can be seen moving pretty close to dead center and the glow of Jupiter is on the left. I circled it to make it easier to see.

That worked out pretty well. Well enough that I wondered if there were any other Jovian moons that I might be able to catch. 

Moons like Amalthea are bright enough, but far too close to the glare of Jupiter for me to ever be able to see. Some of them are just too small and faint, but Elara is just bright enough and far enough from Jupiter for me to be able to photograph it with my 4.5" telescope.

Elara and Himalia are in the same group (the Himalia group) of Jovian irregular satellites. With a diameter of 105.6 miles Himalia is larger than tiny Elara, which is just 53 miles across. As you can see from the graphic above (which I created using the SkySafari app), Elara is a bit farther away from Jupiter. It takes 260 days (8 1/2 months!) for it to complete an orbit around Jupiter. Himalia orbits just a bit faster, swinging around Jupiter ever 251 days (That's still a long time.).

I was a little worried because I had some cirrus clouds in the way and SkySafari (by far my favorite astronomy app) doesn't always have the best coordinates for these faint irregular moons. I pointed my telescope at the position listed and saw this:

There's a moving object in the lower right corner which at first I thought was Jupiter's satellite Elara. It was only later (after I put up an earlier version of this post) that I realized that I hadn't checked to see if there were any known asteroids in the area. Sure enough, that's the asteroid known as (933) Moultona.

Well, rats. What I needed was more accurate coordinates. Thankfully, JPL's Horizons System is an easy resource for getting accurate coordinates for small solar system objects.

I pointed my 4.5" telescope at the right place and gave it another shot. Was I able to spot a moon that's just 53 miles across from a distance of over 376 million miles?  Yes, though the glare from Jupiter was far worse than it was for Himalia (and strangely red too).

It's pretty tough to spot in the full frame, so I have posted a cropped animated gif version with Elara in a circle.

According to JPL's Horizons System Elara has an apparent magnitude of 16.625, just over half a magnitude fainter than what SkySafari listed. There's one other irregular satellite of Jupiter that is near to that magnitude: Pasiphae, with a magnitude of 16.877, it's only a bit fainter than Elara. With a diameter of 36 miles it is smaller but, thankfully, it is also farther away from the glare of Jupiter. In fact it is a lot farther from Jupiter. 

Here it is: 

Pasiphae has a retrograde orbit (meaning it orbits backward relative to the orbits of all of Jupiter's regular moons) that takes 764 days to complete. Yes, it takes just over two Earth years to circle Jupiter! Since Pasiphae and even Elara and Himalia take so very long to circle Jupiter, what we are seeing here isn't much of any of their orbital motions. Instead, most of their motion in the sky is because Earth itself is a moving object. During the hour or sow between images Earth moved much more in its orbit around the Sun than Jupiter and its family of moons did, allowing them to be seen against the much further background stars.

Saturn With Five Moons

The Unistellar telescopes are not exactly known for being great telescopes for imaging planets. But that's okay, as they deliver much better images of deep sky objects. But there are times when you want to look at the planets. Thankfully, last fall they implemented a software update that greatly improves planetary imaging for Venus, Mars, Jupiter & Saturn (see my post A Harvest of Planets for more). 

Last night I used my eVscope to look at Saturn:

The view isn't quite the same as what you get in a traditional telescope. When you look through a normal telescope you can see Saturn, its rings and its brightest moons too. But here the view is optimized to show just the planet, so the moons sort of drop out of view. 

If instead you point the telescope at Saturn's brightest moon, Titan, then the view is completely different. 

The optimization used for planets is no longer in place and you can use Enhanced Vision to see farinter objects. I intentionally didn't center things here, but the big bright thing is Saturn, which is completely over exposed. Also visible are many stars and some of Saturn's gazillion moons. How do you tell the moons from the stars? Consulting an app like SkySafari helps, but a surefire way to find them is to photograph them again to see what moves. 

The animated gif below is cropped a bit from the image above. It was made from two images taken 22 minutes apart that were then aligned on the stars. Everything that is moving is part of the Saturn system.

I've got an annotated version below, but can you spot all five of them? Two of them are close to the glare of Saturn itself. Titan is just to the upper right of Saturn and Rhea is in the seven o'clock position, looking here like it is touching Saturn. Along that same line (Titan-Saturn-Rhea), but much fainter and further out is Hyperion. It is basically in the middle of the image. Extend that line further and you come to the much brighter Iapetus. The left of Iapetus is a star of similar brightness and a much brighter star below that. In between those two stars is faint Phoebe. SkySafari plots Phoebe in the wrong location but lists its magnitude at 16.8. 

Finding Phoebe was my main goal here. The best time to catch it is when Saturn is closest to Earth, which it will be later this month. Phoebe is a small (132 miles across) irregular moon in that it isn't completely round. It is far enough from Saturn (8 million miles!) that it takes 550 days (one and a half years!) to make a full orbit around Saturn. 

Here's the annotated version of Saturn and its moons. It's full sized so that you can actually spot Phoebe:

I am happy to have tracked down another faint moon of the outer Solar System.

Observing High Proper Motion Stars

Everything in the universe is in constant motion, even the stars themselves. Yet the stars are so far away that the constellations of the night sky seem to be essentially unchanging. But, everything is moving. 

The various motions of the stars and our own Sun through space can make the nearby stars appear to change their positions relative to more distant background stars. Alas, none of these are the stars that shine brightly in our sky. 

61 Cygni is a binary star that is 11.4 light years distant and can faintly be seen under dark skies. The two stars of the 61 Cygni system are a little smaller and cooler than the Sun. They take over 600 years to orbit about each other. 

I used my Unistellar eVscope to take an image of this system in September 2021 and again earlier this week. As you can see in the image below, this system of two stars is indeed moving relative to the more distant background stars:

This is motion known as 'proper motion' and, I confess, wasn't something that I thought I would be able to see, because I hadn't actually given it much thought and I am happy to know that for the right stars this is pretty easy to observe. The main thing needed (other than the telescope & camera) is time.

61 Cygni isn't alone in having a high proper motion. Other stars have it too. One of them is known as Lalande 21185. It is a red dwarf star located just 8.3 light years from Earth, but it is too faint to be seen without a telescope. Here's an image from June 2021 blinked with one from earlier this week:

Finally, here's the star with the highest proper motion: Barnard's Star:

Like Lalande 21185, Barnard's Star is a cool red dwarf star that is too faint to be see without a telescope. It is located just six light years from Earth.

There are other stars that are near to us that have high proper motions and I'll be spending some of my evenings looking to see if I can catch them as they move through the skies.

It's Not Easy Being Green

The internet has been all a buzz about the "green comet" and falsely raising expectations of how it will appear in the sky.

So why are they calling it a "green comet"? That is a bit odd as all comets have a green glow about them as they get close to the Sun. I suspect that the real reason they are calling it the "green comet" is that its real name, C/2022 E3 (ZTF), is just too much of a mouthful to use and explain.

The comet has risen in brightness to the point where it can barely be seen without optical aid from a very dark sky. This is about as bright as it was expected to be, so all the hoopla about it being "bright" doesn't make much sense. Still, it looks pretty nice when photographed with a telescope.

The comet was discovered at Palomar Observatory in March of 2022. I first saw the comet August 30, 2022 when it was still more than two astronomical units from both Earth and the Sun. Here's how it looked then:

Comet C/2022 E3 (ZTF) 30 August 2022, taken with a Unistellar eVscope

 The comet and its tail are visible at the center of the image. 

I didn't observe it again until earlier this month when the comet was much closer to both Earth and the Sun. Here's a photo from early in the morning on January 12, 2023:

Comet C/2022 E3 (ZTF) 12 January 2023, taken with a Unistellar eVscope

That green color, which comes from ionized diatomic Carbon molecules, is now visible along with the whitish dust tail and a faint narrow ion tail. It is maybe easier to see the details in this animation which shows the comet's motion against the background stars:

 It has been a rainy and cloudy January and I didn't get a chance to observe the comet again until January 21st. 

Comet C/2022 E3 (ZTF) 21 January 2023, taken with a Unistellar eVscope

Again, the green glow of the comet's coma, the dust tail and ion tail are all visible, but with everything looking better than it did on the 12th. Here's an animated gif from images taken the morning of the 21st:

By January 26th the comet had moved far enough north that it was a circumpolar object, which meant that I didn't have to get up before sunrise to see it. Also, because the comet's position is changing relative to Earth, our view of the comet and its tails had changed. Below is a two-frame mosaic of the comet:

Mosaic image of comet C/2022 E3 (ZTF) 26 January 2023, taken with a Unistellar eVscope

I shot this mosaic to capture more of the comet's thin ion tail which was too long to fit in a single frame.

The comet will be closest to Earth in just a few days and when the weather clears I will try to catch it again.