The Scruffy Astronomer

With the winter solstice coming up, it's time to send around my regular viewing list. Those of you who have small telescopes or (like me) are stuck in the city, start by searching for clusters, either open clusters (which are pretty groups of stars) or globular clusters (which are tight spectacular swarms). Once you've done that, start looking for double stars, which are pretty in a different way. One day I'll get around to photographing some... For planets, Saturn and Jupiter are currently your best bet. Here's a photo I took of Saturn. I used budget equipment (about $1000), which I was testing for work. Open cluster: Mel 111 - Coma Berenices Star Cluster (06:55 PM) Galaxy: M 87 - Virgo A (01:55 AM) Galaxy: M 104 - Sombrero Galaxy (02:09 AM) Dark nebula: C 99 - Coalsack Nebula (02:24 AM) Open cluster: NGC 4755 - Jewel Box Cluster (02:24 AM) Galaxy: NGC 5128 - Centaurus A (02:52 AM) Globular cluster: NGC 5139 - Omega Centauri (02:52 AM) Galaxy:...

I came across this photo a week or two back on the ASV's astrophotography Facebook page. Sam (the photographer) had posted it because of the nice placement of the meteor, and was very modest about the rest of the shot. I was less focused on the meteor and more on the rest. After all, it's the South Celestial Pole, which isn't really photographed much. Why is it that the polar area isn't commonly photographed? To be honest, I'm really not sure, but two reasons come to mind. First, lots of people think it's a bit of a dead zone. And they've got a bit of a point. You can see straight away that the big area between The Emu (that's the Milky Way through the Cross and Carina) and the two Magellanic Clouds is pretty empty. The second reason is a bit technical. "Plate solvers", those clever computer programs that read stars and compare them to a database to determine where the telescope is pointing, have a bit more trouble in the polar area. T...

The other day I mentioned that I'd swapped out my guide camera. It turns out it wasn't necessary, and so now I've got an old ASI120MM in reasonable condition. I decided to try setting it up as an all-sky camera. The camera comes with a fish-eye lens, and all you have to do is connect the computer via USB and use some time-lapse software to make a video. I put the camera on a bit of angle iron and attached it to a mini-tripod (see the photo). I was entertaining vague thoughts of putting it onto my mount for an extra view, but I don't think I can run three cameras simultaneously using ASCOM. For image capture I normally use SharpCap 2.9. It's a free download, although more recent versions have become paid software. As always, setting this sort of thing up takes a few goes. There are options that have to be tested out and tweaked, calibrations like dark frame subtraction to be worked out, exposure times to be lengthened or shorted, output formats that work better...

A random walk through the sky When I first started in astronomy ( back at school ), our astro club's observation nights were unplanned affairs. We'd turn up, maybe have a quick squiz at Norton's Star Atlas to see what's up, and then grab a scope. We'd wander randomly from one target to another, exploring the sky on our own. With a plan, you don't miss a target Inevitably though, the day afterwards, someone would start talking about the Lagoon Nebula or some other cool target. When we'd find out where it was so we could see it, we'd find it was just setting in the evening and we'd have to wait six months to see it. (Geek bullying - find some really cool object in the sky, then wait to tell your victim about it until it's too close to the Sun to observe. How very Niles Crane .) Observation nights always go better when you can plan your targets. And it's not just visual observers, either. Astrophotographers want to expose the target for as...

Today's summer solstice post is overshadowed a little by the Grand Conjunction between Jupiter and Saturn. I know you'll all be out watching that - weather permitting, of course, I wrote this post a week or so beforehand. After that, Saturn and Jupiter will go hiding behind the sun, but there are still plenty of things to watch in the sky, including Mars, which is still high, although it's beginning to get small as it moves away from the Earth. I've added a couple of clusters to my list this time. I got both of them from my light-polluted back yard a week or two back. This is my photo of M41, which I took from my back yard using a saxon 1021 doublet refractor of the type that many of you have bought for Christmas. It's very similar to our most popular refractor, the saxon 909AZ3, just a tiny bit bigger. I had it on a tracking mount though, my own NEQ6. This photo gives you an idea what you're likely to see with a small telescope. The photo also shows a fair a...

It's planet season! Jupiter is blazing away in the evening, pretty much unmissable high in the East just after dinner, and Saturn isn't far behind it. If you're up much later you'll see Mars approaching opposition. I had a good look the other night using a saxon 909AZ3 and Mars is about the same apparent size as Saturn without its rings. My mate Paul just got this shot of Neptune, which is difficult, but a beautiful blue. There are plenty of bright clusters like 47 Tuc, and dimmer objects like the Helix Nebula. or the Sculptor Galaxy. Far into the North, the Ring Nebula will challenge you. Here’s the  list of springtime objects. It spans 12 to 20 hours in RA, and is biased to the southern objects. Because we're locked down in Melbourne, it won't be easy for you to see the dimmer objects. The list is ordered by the time targets pass the meridian – that is, their highest point of the night. The Omega Nebula is past the zenith before 7pm, so go for that one first. ...

Over the last few weeks I've posted about a few star clusters. These are groups of stars you can see using an inexpensive telescope from the suburbs while you're under lockdown. Here's another one. This cluster was named after its (supposed) discoverer, the ancient Greek astronomer Ptolemy. It's in all sorts of catalogues, including Messier's catalogue as M7 and the New General Catalogue as NGC 6475. You don't actually need a telescope to see this one. A pair of binoculars will do, because not only is it made up of nice bright stars, it's also quite large. In fact, if you're in a dark sky area, you might see it with your naked eye. The cluster itself is just outside Scorpio. This is a very recognisable constellation that's rising in the East in the evening at this time of year (July). I always think that it looks like a gigantic backwards question mark. I've attached a screenshot from Stellarium, but of course you can use your own: there are lots...

This is what you can do with a small star tracking device. Steve from Tassie recently got himself a Sky-Watcher Star Adventurer, which is like a small equatorial mount designed to carry a camera and normal lens. Steve used his Lumix G9, a micro four-thirds camera with a 200mm f/2.8 lens. This gave him the equivalent of 400mm focal length for a full frame. Using ISO 1250, he took 12 30 second exposures, which he stacked using Affinity. Final touches he did in Apple photos. As to the photo, it’s one of my favourite areas in the sky, the end of the Rho Ophiuchi dust trail. There’s so much there. Just for fun, I've put an annotated version of the photo at the bottom. The bright yellow star is Antares, the eye of the Scorpion. Above and to the left is the globular cluster M4, but between them is the smaller cluster NGC 6144. Continuing anti-clockwise, Alniyat is next, and then the smaller star HIP 80079 to the left of the shot. Below this is (for me, at least) the star of the show, Rho ...

The Winter Solstice is on Monday, the 21st. In many countries, the Solstice is the official start to Winter. After this, while the Southern Hemisphere gets more sunlight, the cooling by radiation into space is still greater, meaning the coldest weather is just starting. This date coincides with the new Moon - so it's a great weekend for astronomy - weather permitting. I've prepared a list of things for you to find. If you’ve got a small scope, look for the Moon, larger planets and star clusters. If you've got a Dobsonian, you can see dimmer objects. My target this season is the Lagoon Nebula. I've never got that before. This one is Josh Carnovale's. I've sorted the list by the time each object passes the meridian, so start at the top of the list. Clear skies! ⦁    Mel 111 - Coma Berenices Star Cluster (06:55 PM) ⦁    M87 - Virgo A Galaxy (06:55 PM) ⦁    M104 - Sombrero Galaxy (07:09 PM) ⦁    NGC4755 - Jewel Box Cluster (07:24 P...

The Autumn Equinox is tomorrow, the 21st of March. I've prepared a list of things for you to find. Remember, the the new Moon is on Tuesday (the 24th). If you’ve got a small scope, such as a refractor, star clusters work best for you. If you've got a larger aperture, you can see dimmer objects, such as my Running Chicken. I've ordered it by the time each object passes the meridian, so start at the top of the list. As to planets, Venus is low in the west in the evening, still bright enough to be seen in the sun’s glow, and a pleasing crescent. Mars, Jupiter and Saturn are clustered before sunrise. Clear skies! Galaxy: Large Magellanic Cloud (06:43 PM) Globular cluster: M 79 - (06:43 PM) Bright nebula: M 1 - Crab Nebula (06:57 PM) Bright nebula: M 43 - De Mairan's (06:57 PM) Diffuse nebula: M 42 - Orion Nebula (06:57 PM) Bright nebula: NGC 1977 - Running Man (06:57 PM) Bright nebula: NGC 2070 - Tarantula Nebula (06:57 PM) Dark nebula: B 33 - Horsehead Nebula (07:12 PM) D...

Dimming update? Back at the end of December, I posted that the red supergiant Betelgeuse, in the constellation of Orion, was dimming visibly . It used to be one of the brightest stars in the sky, and now it’s not even in the top 20. Yes, it’s less than half as bright as it was just over a year ago. Red supergiant stars such as Betelgeuse normally end their lives in supernovas, which would be seriously cool to see. We’d be quite safe here, at a good enough distance, but we’d be able to see the explosion as it happened during the day, and it’d be months before it dimmed. There are other possible explanations for what we’re seeing. One theory that might be quite feasible is that a large and dense gas cloud has passed in front of the star. This sort of thing does happen, and would explain the phenomenon quite well. Since the star’s dimming has been in the news, more and more people have been watching it. Most recent reports suggest that the rate at which it’s dimming...

You’ve probably heard in the mainstream media that there’s a star in Orion that’s gone dim over the last couple of months and might "go supernova". Maybe, but don’t hold your breath. Betelgeuse is a red giant star in the constellation of Orion, one of the shoulders of the Hunter. Of course, in the Southern Hemisphere, we see it "upside down", so Betelgeuse is the lowest bright star in the constellation. Just now, from Southern Australia, Orion is rising in the East after sunset. A red giant is a huge star. If it were transferred to where our sun is, the Earth would be inside the star itself. So would Mars and – nearly – Jupiter. Only large stars can result in supernovas, but this one is plenty big enough. It’s also true that it’s gone suddenly and significantly dimmer over the past few months. Betelgeuse was until recently one of the top 10 brightest stars in the sky. Now it’d struggle to make the top 20 list. However, it's also variable, changing brig...

20 December 2019 In my post on the Spring equinox I mentioned it was a pretty sparse time for astronomers. Well, that's over, and the Summer glut of things to catch is here! Start with 47 Tuc, the Pleiades, try the Sculptor Galaxy, then a bit later move to M42, the Great Nebula in Orion, and just go from there. The one I'm waiting for this year is the Rosette Nebula. The Rosette itself might be too dark to see with anything but a large telescope, but it also has a pleasant star cluster in the middle. It's also huge, 1.3 degrees, so you'll need the longest eyepiece you've got. This is suited to a Dobsonian telescope which has a low focal length and wide aperture. Here's the list - as usual I'm giving you the name as well as its rough transit time - the time on the 21st when it's highest in the sky. Some of them don't set. My poor photo is the Horsehead and Flame nebulas in narrowband. Globular cluster: NGC 104 - 47 Tucanae (07:55 PM) G...

Note that this blog post was rewritten to reflect that the planet has been named and the competition website has now been discontinued. A southern-only star, with a planet discovered by an Australian astronomer at an Australian observatory – well of course it has to have an Australian name! In August 2019, the Melbourne Age had an article about how the International Astronomical Union has asked Australia to name a planet, along with the star it’s orbiting. But Planet McPlanetface? Oh, change the record.  The competition The star itself is pretty unassuming. It’s not visible with a naked eye, and currently only has a catalogue name - HD38283. But if you know where to look, and have a pair of low-power and large objective binoculars (say, a 7x50), you can actually see it. Being out of the city would help a lot, too, as it’d take a lot of finding.  This is a screenshot from the free planetarium program Stellarium that shows HD38283 in relation to the Southern Cross and Carin...

  The Winter Solstice is here, and the nights are long and cold. For “normal” people, this is a bad thing, but for astronomers it means hours of viewing with cold crisp air making for good seeing conditions. If the clouds stay away, of course. I've prepared a list of things to look at in winter. Of course, new Moon is the best time for seeing the dimmer ones such as the nebulas. Remember also that the size of the target will determine how well you’ll see it in any particular scope. Sometimes magnification isn’t your friend! I've ordered it by the time each object reaches its highest point, so it'd be best to start at the top of the list, as these will be starting to set (some don't set at all). The picture is my unguided attempt at Rho Ophiuchus, the neighbour of the Dark Wolf nebula. This is highest at 10:10pm on the 21st of June - you’ll need a good dark site though. Dark nebula: C 99 - Coalsack Nebula (07:15 PM) Open cluster: NGC 4755 - Jewel Box Cluster (0...

24 April 2019 Occultation of Propus ( η Geminorum), 11 April 2019, 21:32 (ACST)   This was a totally unexpected happening. Dean and I had made camp at Acraman Bore (with the permission of the station manager, of course). We were relaxing after dinner, and watching The Emu come out to our south. I was using my binoculars to wander around the sky when I noticed the Moon was especially close to a reasonably bright star. Were we were going to see an occultation? An occultation is when the Moon moves in front of a star. It actually happens all the time, but it's hard to see unless it's a bright star, as the Moon blots out everything around it. But usefully, when the Moon is a crescent, it has dimly lit side. This dim light is reflected off the Earth, and you can see stars right up to this side. Interestingly, this means that occultations normally only happen in the week or more prior to the full moon, as during this time the Moon appears to move towards its dim side. After t...

22 March 2019 Welcome to the Autumn Equinox! For the stargazers among us, I've prepared a list of things to look at at this time of year - better when the Moon goes away, of course. Some are suited to larger scopes, but clusters work well in small ones. I've ordered it by the time each object reaches its highest point, so it'd be best to start at the top of the list, as these will be starting to set (some don't set at all, remember). For example, the picture is my dodgy effort at M83, which rises at 20:18 and sets at 09:45 tomorrow, reaching the meridian at about 3am. Good hunting! Galaxy: Large Magellanic Cloud (06:49 PM) Globular cluster: M 79 - (06:50 PM) Bright nebula: M 1 - Crab Nebula (07:00 PM) Bright nebula: M 43 - De Mairan's Nebula (07:01 PM) Diffuse Nebula: M 42 - Orion Nebula (07:01 PM) Bright nebula: NGC 1977 - Running Man Nebula (07:01 PM) Bright nebula: NGC 2070 - Tarantula Nebula (07:04 PM) Dark nebula: B 33 - Horsehead Nebula (07:06 PM) Diffuse nebu...

27 February 2019 We're always being asked how to get a good polar alignment on an equatorial mount. There are several ways, and how you do it is going to be determined by what hardware and software you have, so I won't bore you with details (although you can ask us). But the most important thing that helps is being able to locate the pole in binoculars. It's difficult, especially in the inner city, but with a bit of practice and perseverance (and insect repellent) you can find it, and then come back to it again. Then, once you've got it in your sights, you'll know immediately where "roughly polar aligned" is, so you can get your mount set up quickly. Even some experienced photographers think this is too hard for them. It's not! The first big tip is don't start with your polar scope or telescope - those magnify too much. Start with low power binoculars. My first photo shows you (best on a screen) how to get into the area from the South...

31 December 2018 How well do you know your neighbours? Alpha Centauri (Rigil Kentaurus, or just Rigel Kent) is not just a single star. It’s not even a double, it’s probably a triple. Alpha Centauri A and B appear as two stars very close to each other in a telescope. You have to have a scope with a long focal length to be able to split the two. When I was a kid, we used to judge how good people’s scopes were by looking at Alpha Centauri to see if the scope could split the binary pair. To do it, the scope needed a lot of light gathering ability, good optics, and a long focal length. That probably also suggests a lot about what I was like as a kid. The distance between these two stars is only about 11 times the distance between the Earth and the Sun. The pair dance with each other, taking about 80 years to complete a do-si-do. Any planets nearby would be well cooked. Their poor neighbour, Alpha Centauri C, is dull red, nearly invisible and also about 0.2 light ye...