VicSouth Desert Spring Star Party

Pretty much exactly what the name says, the VicSouth star party happens every year at the Little Desert Nature Lodge just outside of Nhill. It’s usually held over the Melbourne Cup not-actually-a-long-weekend, and this year I was fortunate enough to be able to go for most of the weekend. I was very excited.

The event itself

… was very well organised. The location itself is excellent for astronomy – James checked the sky each night and got readings to indicate it’s the darkest skies we’ve ever observed under. There’s a big field that’s perfect for setting up many telescopes; there were lots of cables running to power but that’s always going to be the case. The field’s flat, it’s grassed, and it’s near the dining room which meant that the urn wasn’t too far away when it got to midnight and we were cold but still keen.

The location also works well during the day. We splurged and got a cabin – nice to collapse into a good bed – and we also went with the food package, which meant lunch and dinner. The dining room comes with big round tables that seat 8-10, which meant that we were forced to talk to people (the horror!) at each meal – we had some great conversations about astronomy and even other things. And the food was pretty good too. The organisers planned things for during the day, and I even got to some of it despite needing to nap each afternoon to prepare for the night’s viewing. A number of people volunteered to give talks, on everything from the geology of the local area, to ways the universe is trying to kill you; from astrophotography to organising your observing lists. It was a pretty good mix. And apparently each night there was a movie on the screen (including On the Beach), but I didn’t get to those.

The observing

I went without any preparation, except for the vague desire to get up and see Comet ISON. Since that’s the only thing that could be called a goal, as of the Friday afternoon, you could say that I failed, since 5am did not see me awake on any morning. Given that a small group of people did get up and then reported that it was a fizzer, I’m not too fussed.

We only got in a couple of hours on my first night before the clouds rolled in. Had a great view of Venus… because for a while it was pretty much the only thing to look at, given its insane magnitude and height in the sky. Also 47 Tuc, which rather started a theme for the weekend… I do love me a globular cluster.

The next night more than made up for the first, though, and we stayed up until about 2.30. I had made a List, and got through a number of doubles before I got distracted. I looked at some globular clusters, including some in the Large Magellanic, which I didn’t realise you could do. I also looked at Uranus and Neptune – to my everlasting delight we bagged Triton, Neptune’s main moon, too. James contributed to my distraction by convincing me that Andromeda through my ‘scope was the best idea, given its wider view; and we managed to see the two other galaxies around it, too, which did indeed look spectacular. He was concentrating on some faint fuzzies, and called me over to test my eyesight on some mag 13-14 galaxies… most of which I managed to see, or at least could convince myself that I did. And of course I greedily admired the Orion Nebula; I will never ever get bored by it. I was sad by how late Jupiter was rising – I saw it through the trees, and the Galilean moons were all in a row, but the view was utter mush.

The last night of viewing was also spectacular, but we sensibly didn’t stay up as late since we had to drive home the next day; so we pulled out at about 1.15. Again, I bagged a number of double stars – to my delight I discovered that I could split down to a 4″ separation! I didn’t think that was possible through the 120mm. I looked a few open clusters, but mostly they bore me; the Ink Spot and cluster of NGC 6520 were pretty cool, though, as the dark nebula of the Spot was quite noticeable with it being so dark. Again I got distracted by globulars, doing so a bit more systematically by dialling up all the globs in Sagittarius (there are so many Messier objects there!) on the Argo and working through most of them.

And there was observing during  the day, too. I had taken my solar scope, but someone else had their much-bigger, double-stacked one rigged up next to a white-light solar scope, so… yeh. Mine didn’t come out. I was mighty impressed with his set up: he’d got a piece of core flute, and attached to the scopes, so that they acted as a sun shield. BRILLIANCE. But, um… maybe a little bit TOO attractive….


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UHC, Oxygen III and Hydrogen Beta Filters by Astronomiks

OIII Transmission

If you own a scope 8 inches or larger then filters can make a big difference to the fine details you see in a range of non-stellar objects. They work by blocking out some wavelengths of light, while allowing full transmission of others. Depending on their type and composition, different nebulae emit light at different wavelengths and by using a filter matched to these the overall background and star brightness is reduced significantly more than the nebulae itself. While all filters cause some overall reduction in light transmission, the differential reduction of the background (especially under light polluted skys) and the transmission of the nebulae’s specific emission lines increases the relative contrast allowing the eye to see more detail than is possible without the filter.

Filters are not magic; their effect is minimal or negative for many objects because of the reduction in total light transmission. However, for some objects – especially marginal ones – the contrast increase can make it significantly easier to make out the details of an object. The Tarantula Nebula in the LMC is one of my favourites to view through a UHC or OIII filter: it reveals different and fascinating details through both. The OIII filter is also ideal for making planetary nebulae stand out from the background stars. NGC2438 in M46 is a excellent example for this.

UHC Transmission

David Knisely has done an extensive and detailed comparison of the UHC, OIII and Hb filters on almost 100 objects using a 10 inch scope. I’m not going to try and replicate this excellent analysis; instead I recommend you read the descriptions for objects you’re familiar with to get an idea of the improvement you can expect with the different filters.

Many companies make filters. Personally I have the UHC, OIII and Hb 2″ Astronomik filters mounted on a moonlight filter slide with a heater strip and temperature sensor set up to keep them dew free. The filters don’t appear to introduce a colour cast, or any other undesirable artefacts when viewing. They do however require a slight refocusing when changing between a filtered and non-filtered view.

Like many astronomy accessories filters are not cheap, so here’s my buying advice. If you’re only going to buy one filter, get a UHC. Next buy an OIII, especially if you enjoy planetary nebulae. An Hb filter is honestly an excessive luxury, but if you have a big Dob (15+ inches) and you want to be able to enjoy some very faint nebulae objects like the Horsehead it makes a noticeable improvement.

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Astronomical Society of Victoria – Annual Messier Star Party

Last year we became members of the Astronomical Society of Victoria and one of the perks is access to the club’s dark site. Each year they run a few public access events to promote the club and astronomy, so we took it as a good chance to head up – check out the dark site and share our scopes and love of the night sky with some new folks.

We headed up under perfect clear blue skies and set up on the main field – I picked a spot between three big Dob brothers, an 18″, 20″ and 25″. Secretly I hoped they might act as a bit of a decoy for my baby 16″, to keep away most of the crowds, but once again the magic of observing with both feet on the ground seemed to draw people in. Alex set up our 5″ APO next door; she drew a bigger crowd than me!

It was fabulous to see so many people having their first experience of astronomy under a proper dark sky (SQM 21.5 last night). The local Lions Club put on food, the club put on a range of short and interesting talks as well as tours of the site, and after dark one of the night sky.

The evening started off pretty quietly with most of the visitors engaged with the night sky tour but that soon ended and for the next few hours the observing field was awash with the curious, interested and far too many far too-bright red lights. But hey, we’ve all gotta start somewhere.

In keeping with the Charles Messier theme of the evening I made a point to try and show people a few interesting Messier catalog objects as well as a number of the usual showpiece objects. I also always like to show people one or two of the more impressive galaxies that are up too; regularly seeing these objects which put everything else in the sky into context is one of the privileges of owning a big scope.

Over the evening I observed and shared these and more:

M46 OC + NGC2438 PN
NGC 3115 Gal – Spindle Galaxy
NGC 5128 Gal – Centaurus A (saw the bright strip through the dust lane)
M104 Gal – Sombrero Galaxy
NGC 2392 PN – Eskimo Nebula
NGC 3242 PN – Ghost of Jupiter
M42 and M43 Neb – Great Nebula in Orion
NGC 1365 Gal – Zorro is sadly chasing the sunset at this time of year.
NGC 2024 Neb – Flame Nebulae.
B33 Dark Neb – Horsehead (Hb Filter) – With Orion high in the sky it was the easiest view I’ve had of the normally elusive Horsehead, I managed to show Alex and 2 or 3 others who all saw it. Normally I struggle to see it myself, let alone help anyone else see it.
NGC 2070 Neb – Tarantula and region in the LMC
NGC 3372 Neb – Eta Carinae
47 Tuc GC
NGC 5139 GC – Omega Centarus
NGC 4755 OC – Jewel Box
NGC 3293 OC – Gem Cluster

While I wouldn’t want all my observing sessions to be like this it feels good to go and be part of an event like this a few times a year.

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Pocket Sky Atlas

Just buy it.

Seriously. Just buy it. Are you just getting into astronomy? Can’t actually buy a telescope yet but interested in learning about constellations and the various objects you’ll be able to see when you do get one? Just buy this. Been observing for a while but don’t have a nice handy little reference to take with you for short sessions at the telescope? Buy this.

We own two, because we each need one when observing. (And we’re bad at sharing.)

Halfway between A5 and A4 in size, and spiral-bound, this is immediately an appealing book. The blurb describes it as fitting into the glove box, which is a good way of selling it. It’s not quite a genuine pocket-book, but compared to most atlases it’s a treat. It has slightly waxy pages which means they don’t mind a bit of dew, too, which is marvellous when observing in damp conditions.

The book opens with a very brief introduction, explaining the origins of the atlas – in the search for convenience – and what it actually shows – stars down to about mag 7.6; doubles, variables, galaxies brighter than 11.5, globular clusters brighter than 10.5, planetary nebulae brighter than 12. It also explains the labels used, how the charts are arranged, and includes a select bibliography which can be used for those wanting something than goes further (or just a good collection…).

The charts are arranged in order of Right Ascension, in sets of ten. It begins with RA 0-3, and the introductory page (a similar one appears at the head of each ten) explains in which months this part of the sky is high in the evening, at midnight, and in the morning (in this case, Nov and Dec; Oct; Aug and Sept). It also has a map, repeated in many places, of the entire sky, with major constellations and the maps on which they appear; the section under specific consideration is shown in bold. Turn the page and, before getting to the maps themselves, there is a key to understanding the maps: how to identify galaxies, nebulae, clusters, and stellar magnitudes.

The maps themselves are quite detailed, with lines connecting the stars of a constellation in green, galaxies in red and other non-stellar objects mostly in yellow. Each map has arrows and labels showing which other maps it connects to (there is good overlap), and RA and Dec are easy to follow. There are four detailed maps: of the Pleiades, of Orion’s Sword, the Virgo Galaxy Cluster, and the Large Magellanic Cloud.

One of the most useful aspects of this map is that the front cover is not part of the spiral binding, meaning that when the book is laid open the front cover juts out beyond the page. On this jutting-out section there are three things: a ruler indicating angular distance on the charts (up to 15 degrees); the scale for determining star magnitude from -1 to 7 (because as usual this is indicated by relative size on the map); and a red Telrad finder with circles at 2 and 4 degrees. For quick referencing while observing, this inclusion is invaluable.

The book closes with several indices. It has a list of bright stars, by name; a list of galaxies by NGC and IC reference, as well as name; open clusters; globular clusters; bright and dark nebulae; and planetary nebulae. All of these, listed separately, also have a reminder of the legend used to indicate them on the maps. Lastly, the book includes objects in the Caldwell Catalogue and the Messier Catalogue. Excellent for those of us who like lists and/or challenges, or who are feeling lazy when it comes to planning an observing run.

Would I buy it again? I already mentioned that we own two, so: absolutely. It’s invaluable.


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Double Star Atlas

When I announced that I might be interested in checking out double stars, James bought The Cambridge Double Star Atlas, by James Mullaney and Wil Tirion, for me. It’s a big book – larger than A4 – although only 148 pages long. It’s spiral bound, meaning that despite its size it’s quite useable: you’re not forced to to deal with an A3 map on your lap while at the eye piece. The paper seems to be good quality and slightly waxy; I’ve had mine sitting on dewy grass and although some of the pages have slight ripples in them now, the book itself hasn’t suffered at all. And it’s got wonderful content, with an excellent introduction and superb maps.

In the introduction, Mullaney takes the reader – anyone from a novice to expert – through the process of making the book itself, then tabulates the codes that are used to signal the discoverer and/or catalogue used when discussing individuals pairs/systems. There is an excellent section on the practicalities of observing – useful not just for doubles hunting – explaining how to train the eye to observe, as well as the impact of sky conditions and the resolution and magnification of telescopes. He also discusses the idea of record-keeping, and it was from reading this that I decided to keep a journal of my observations.

Before getting to the maps, Mullaney has a list of 133 ‘showpiece’ double and multiple stars. As well as giving the name of the object, its coordinates and magnitude, he includes a short and usually evocative description of each object. For those of us who like lists, this is something akin to having a Messier list for double/multiples. It’s a fabulous challenge (although disappointingly for me a fair number are beyond my viewing range, here at 37 degrees south).

The heart of the book is the 30 double-page maps that cover the entire sky (p1 is the North Celestial Pole, p30 the South). The maps show about 900 non-stellar objects as well as the doubles, so it can make an excellent all-round atlas too. The stars making up constellations are connected by faint blue lines, and the ‘spheres of influence’ of the constellations is also shown, which is useful when trying to locate specific objects. The doubles that are specifically listed objects (all 25,000 of them) are labelled in green, making them easier to read under red light. I’ve never been especially good with maps, but these are easy to read and easy to use, both while planning an observation session and while at the telescope.

Finally, there are the Appendices. App A lists the constellations and which pages they appear on; B has the ever-useful table of Greek letters. But C is where the money really is: a list, in order of RA, of the doubles Mullaney specified be in the Atlas. The table has the object’s designation, RA and Dec, magnitude, and the pair’s separation, as well as occasional helpful remarks (this is Antares, this is in the middle of the Pleiades). This appendix can be used to give the astronomer a better idea of exactly what she is looking at on the map; when used in conjunction with an Argo, if a random double is spotted it can be looked up via the RA/Dec to see whether it is listed and if so its name.

Would I buy this Atlas again (or get James to buy it)? In a heartbeat. Of immense value to anyone who is interested in looking at double stars. It’s easy to use, lovely to flick through when planning, and sturdy into the bargain.

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Astronomical Sketching

It’s fair to say I have a bit of a reputation among friends for being a bit of a luddite. I collect vinyl records, only use cameras which take celluloid film and I think humanity’s greatest technical achievements may be the Apollo program in the 1960s. Given this it seems quite logical to me that I would find sketching more appealing than astronomical imaging, especially with one of those new fangled CCD cameras.

So why sketch at all? Well, a few reasons, the first is it’s a very simple and cheap way to capture and share what you see through a telescope. I think this is particularly valuable as it gives quite a good impression of what an observer sees visually through a telescope rather than the colourful but misleading candy we see from amateur images right through to professional images from the Hubble. I think the second reason is it makes you a better visual observer; the very act of building up a sketch forces you to take a second, third, fourth and many more looks at the object of interest. There is something too about the way the brain works which means once you have seen a detail once and noted it down, somehow it’s easier to see it again, even if just using averted imagination.

I started out sketching images of the moon. Partly this is due to our inner city home and partly because I think it’s probably the easiest target to start working on. The moon is so bright it’s quite easy to have an outdoor light on while you draw, in fact having a light on can help balance out the blinding bright appearance of the moon through all but the smallest of telescopes. Once I’d made a few drawings of the moon I was happy with I started working on other bodies in the solar system, mostly Jupiter. Lately I’ve begun sketching some of the deep sky objects, but this is still very much something I’m learning to do well.

Tempted ? Good. Here is how I suggest you start: get a copy of this book.

Buy some pencils – I have a box of 12 Derwent Drawing pencils but when you are just starting limiting yourself to a few pencils makes life easier. 4B, B and 2H is about right. It doesn’t matter though if it’s 3B or 2B and 4H etc. A B pencil is my standard go-to pencil. I never grab more than 4 pencils for any one sketch in the field. You also need to get a blending stump or three (you can get away without cleaning them all the time if you use the same one for really soft black pencils, and keep one pretty clean for light smudging). Also buy some different erasers, including a soft ball-style one and an eraser shield – the eraser shield might be the most important thing you buy. Finally you need a decent pad of A5 drawing paper. If you go to an art store all of this should cost you less than $40.

Beyond the tools the most important thing to practice is figuring out your reference points, and drawing those first. For the moon, big craters and the key shadows. For star clusters, focus on the brightest stars first. For nebula, the bright stars and basic shape. Once you get those down, you just keep refining, and refining sections of the sketch. Breaking it down makes it much less overwhelming.

Finally, for a bit of inspiration check out Astronomy Sketch of the Day.

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Observing the Sun with Coronado Telescopes

While it does discuss other brands, this book – as the name suggests – is designed to inform the reader about solar telescopes as made by Coronado (acquired by Meade in the last few years). Overall, it is a nicely presented book, with some detailed information about the telescopes and solar observing in general. The pictures in particular are a wonderful part of the package: there are numerous pictures of the sun itself, taken via Coronado instruments, which demonstrate what it is possible to see, as well as numerous pictures of the instruments themselves. However, this book is not without its flaws.

The thing which frustrated me the most about this book was the poor editing. It’s not so poorly written that it becomes unintelligible, but it is filled with enough silly mistakes to become quite irritating: mistakes which the author ought to have picked up on re-reading, and which an editor certainly ought to have corrected. That aside, the non-technical sections are clearly written and easy to follow. The audience is definitely imagined to be beyond novice at astronomy; unless you are an astronomy novice but an experienced photographer or otherwise have a good working knowledge of lenses, there will be sections of this book that will be difficult to follow. It’s also written in quite an idiosyncratic style. Philip Pugh, the main author, acknowledges this early on; it’s based largely on what he, and the other contributors, have personal experience with. They do mention some accessories and telescopes they haven’t personally used, which is good, but does leave room for the possibility that they’ve missed something. It also has numerous personal anecdotes throughout, which in general I found quite nice, although the mentions of business trips to Brazil got a little wearing.

Fortunately, the flow of the book itself is easy to follow. It opens with an exceptionally detailed contents page, and there are clear headings throughout all of the chapters. The Introduction begins with a little bit of the history of solar observing – but so little that he might as well just have skipped on it. It also includes a smattering of scientific information about the sun, which again was so limited that it felt like it didn’t really fit. Both of these really needed to be quite separate sections to feel warranted. The best part about the Introduction is Pugh’s discussion of the differences between white light and hydrogen alpha (Ha) observing in terms of what the eye can actually see, as well as his recommendations on how to keep records of observations. Reading the introduction is probably a good way to decide if solar observation is really for you: it’s certainly cheaper than buying a telescope and discovering that you hate it.

Chapter 2 focusses on the PST: the Personal Solar Telescope, one of which I own and is the reason why I bought this book. This chapter is excellent if you are considering buying one. It has great detail on what the PST looks like; how to attach it to various types of mounts; accessories (he doesn’t always come down in favour of the official ones); and how to find the sun using its inbuilt finder. There is a great deal of information about eyepieces, and includes an interesting appraisal of the PST overall.

Chapter 3 looks at the PST’s bigger sibling, the MaxScope. The chapter is largely the same as Chapter 2, although it has more information on photography. I am unlikely ever to even consider the MaxScope, so I will admit I did not pay a great deal of attention to the chapter details; it does seem as thorough as that on the PST, however.

Other Coronado products are the focus of Chapter 4. It seems to be a good rundown of the various options, with useful comparisons to other Coronado products throughout. It includes a brief section on accessories and options for mounting.

Imaging the sun is discussed in Chapter 5. This seems to be something a lot of solar observers get into, and while I was unconvinced when I first started using the PST, the appeal is slowly growing on me. The chapter includes very detailed discussion of how to attach and use a webcam (the best option for solar photography it seems), as well as post-processing and the advantage of stacking images. There are some lovely photos, of course, to serve as inspiration. The problem, of course, is that although this book is quite current – written in 2006 – the rate of change in digital imaging and associated software has been so rapid that this chapter is almost certainly hopelessly out of date in terms of its recommendations regarding the best or cheapest options for cameras, and what software to use (additionally he only suggests software for Windows machines). This chapter might give an interested imager somewhere to start, it could by no means be used as a sole guide.

In Chapter 6, the book moves away from Coronado products to give brief reviews and evaluations of solar telescopes and accessories from other brands which the authors have tried, while Chapter 7 discusses products they have not personally experienced. Having no experience with these things I of course cannot evaluate whether they are being completely fair or not, but the book as a whole gives no reason to suspect anything other than honesty.

Finally, Chapter 8 provides a fairly comprehensive summary of the book as a whole, and it concludes with a glossary which, while not being very detailed, is still useful.

Would I buy this book again? Probably not. It’s not the book I was expecting; I had hoped for more on solar observation itself, not what is essentially a buyer’s guide. Since I am unlikely to buy another solar telescope (my PST suits me down to the ground) it isn’t particularly useful. This is the sort of book which ought to be in libraries – particularly astronomical society libraries – where potential buyers can borrow it to read the relevant chapter.

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