Wednesday 12th December 2017
8.30 to 10pm Moon just past first quarter
A while ago at the club, someone suggested I try and see all six stars in the trapezium with my 16 inch Dobsonian. Last night was really clear and I managed to see all six. I had a vague recollection I’d managed this before, but have only been able to see the four brighter stars the last few times I’ve tried. It must be something to do with seeing conditions/transparency.
All six stars were visible in my Vixen LVW 13mm eyepiece, which provides 155x magnification in my scope. The fainter two stars weren’t visible in my 8mm Televue Radian eyepiece, but I recall seeing them in an old Televue plossl eyepiece I used to own.
Comparing the two faint stars, the bottom one is slightly more inclined towards its neighbour, whereas the top one is pointing out more to open space. The bottom one is easier to see, but both stars were coming in and out of view, depending on atmospheric conditions.
A little bit more of interest this morning.
Following pictures show astronomy-related presents I received this Christmas – in particular the amazing framed American eclipse stamps from Damian and the beer from Ean Ean.
The beer glass says, “I love you to the moon and back”.
The beer is brewed by “Meantime Brewing” at Greenwich, London.
Well, it’ not starry, but I an around Damian and Julie’s watching Carols from Kings and Damian has leant me his favourite cup for coffee with brandy – well it tastes more like brandy with touch of coffee – delicious!
Probably closest I will get to s starry night tonight but Christmas is all about a baby born in a stable, pointed out by a star – possibly a kilonova? I wonder – the Star of Bethlehem might have been the first example in history if recorded kilonova.
Only the briefest of opportunity to see our local star today,and even then only in white light. There is a small spot system on view, although it is quite complex and interesting. (See SOHO image)
On BBC Sky at Night TV show a few months ago, they collected micro-meteorites from roof collection at the Norman Lockyer Observatory in Sidmouth, UK. Rhys and I ordered some neodychromium magnetd and today we mounted them on a piece of spare wood using some small screws through their central holes. We put the wood and magnets, magnet side down, in the guttering on the front of our house in Lichfield, UK.
Hopefully, this will extra small metallic debris from the water running off the roof when it rains over the next few months. Again hopefully some of this will turn out to be micro-meteorites.
Andy and Rhys
The bargain centrifuge has one problem.. …the timer didn’t work – it was like this when I bought it from ebay. I purchased a new timer from America (see previous posts). It arrived today and I spent an enjoyable hour dismantling the centrifuge and replacing the timer. A lot of dirt and much inside after 30-40 years and the timer was all rusted up. It is spring driven – I know, unbelievable in this digital age! The new timer is supposed to be the same but in fact the casing is slightly different shape so out came my hammer and pliers to bend the bracket it fixes to in the centrifuge to a accommodate the new one. After modification the bracket could only be reattached at one end so my trusty glue gun sorted out the other side. Sounds Heath Robinson but all worked well enough and you can’t see anything once the case is put back together.
What impresses me most is that I have managed to fix this without the help of Ed or Led or Pete – great guys, really helpful, but I am pleased to manage to do it myself this time.
- Mira in Cetus is about to increase in brightness- see attached section of SPA notification.
Mira the Wonder Star approaches maximum
The star Omicron Ceti, Mira, has a special place in the hearts of variable star observers, as it was one of the first stars to be recognised as being variable. It spends most of its time well below naked-eye visibility, but then over a matter of just a few weeks it brightens up and again joins the constellation pattern of Cetus.
It was this behaviour, first spotted in the 16th century, that earned it the name of Mira, meaning ‘Wonderful’. Until that time, stars were supposed to be fixed and unchanging.
Mira has recently brightened and is now again just visible to the naked eye, though at the moment it is still around magnitude 5, which is on the verge of visibility from most UK locations. However, it should get brighter, as its maximum is expected to be in a month or six weeks, around mid to late January.
A normal maximum is around magnitude 3.6, which would make it visible from typical UK suburban skies but not dramatically obvious. However, because the star is brightening fairly early in its rather irregular cycle of around 332 days, it could be that it becomes significantly brighter than usual, so it is well worth watching out for.
The peaks of 2007, 2010 and 2011 all reached around magnitude 2, so Mira then became virtually the brightest star in Cetus. In some years, maximum occurs when the star is too close to the Sun to be observed, but the coming maximum will take place when the star is easily visible in the evening sky.
Use the chart here to pick out Mira, which is best found by first using the stars of Aries to locate the brighter stars of the Head of Cetus, which is shown by a polygon just above Mira itself.
To make estimates of its magnitude by comparing it with nearby stars, take a look at our Variable Star Section’s news story, which provides a list of comparison stars and their brightnesses. There is also a link to more information about Mira.
2. The latest edition of Sky at Night Magazine (January 2018) also has information about Mira (p.59) as well as an article by Paul Abel on how to estimate the brightness of variable stars. ( p.79/80)