Janus



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The PDF version of the November 2017 edition of Janus is available by clicking the link at the bottom of this page...

Gary Walker - My Observations of the close passage of Asteroid 3200 Phaethon

 

Last night (December 13th-14th), I managed to find the asteroid 3200 Phaethon, which is doing a close passage to the Earth - especially on December 16th, or so.  It will pass, on that date, about 10.7 million km's from Earth!

 

I used the "The Sky Live" website which gives its sky coordinates at 24 hour intervals, like I did with the previous NEO in September.  The times are given for 12.00am UT.

 

On entering the coordinates in my GOTO system under "User Objects", the scope slewed to the correct position.  At first, I could not tell, which (IF ANY!) of the numerous stars in the starfield, were not what they were claiming to be.  I first thought a faint star, was the one (as I knew the asteroid would be faint, being as it is between magnitudes 10 and 11), but saw that that star was NOT moving!  Then, I thought that I saw another, brighter star HAD moved, so I started watching that.  However, it was only when it got very close to stars,that I could see that it was moving.

 

Mostly, its motion was like watching the minute hand of a clock, but when it passed very close to a star, I could see it almost moving in real time, and the angles changing between the star and the asteroid.  The asteroid was brighter than I had expected, and thus easier to see in my scope.  I found the best magnifications were either 100X or especially 166X.  With these higher powers, the asteroid appeared brighter than it did at 62X.

 

The asteroid only appeared white in colour (presumably not bright enough to show any more colour).  It was in the constellation of Perseus and was high up in the west.  I observed it from c.12.05am to 12.44am.  The asteroid was moving East to West.

 

This NEO is the 4th such one that I have managed to observe between 2015-2017.

 

This asteroid is an Apollo earth-crossing orbit one, and is about 5km in size.  It was discovered in 1983 by IRAS satellite data.  Interestingly, it is the source of the Geminid meteor shower, which occurs about this time, too!  Astronomers are uncertain, if it is an asteroid emitting dust from cracks created when it passes close to the Sun, or else it is a dead comet.

 

 

I also checked on the variable star, Mira, in Cetus.  Back in October, it was only the same magnitude, as a handily-placed non-variable star, of magnitude 9, very close to it.  By November 16th, I saw that Mira was slightly brighter than its 'companion'.  However, last night, Mira was far brighter than its 'companion', so it has significantly brightened since November!  It seemed to start brightening up during November.  

 

This star, was the first variable star discovered and was termed "Mira, the Wonderful", as before that, stars were seen to be unchanging!  It cycles in about 332 days from Minimum (magnitude 9-10), up to about magnitude 2-3 maximum, and then back down again.  It is varying so much as it is a pulsating Red Giant star.

Gary Walker - And yet more "SuperMoons"! - or Honey, we blew up the Moon!

December 4th 2017, saw yet another "SuperMoon"!  We have already had an earlier one in November, and there are TWO more "SuperMoons" occuring at the begginning and end of January 2018!  Thus, the "SuperMoons" seem to be spreading out over a longer and longer period, so they become more frequent!


Yes, once again, all the newspapers were full of dinner plate  - sized Moons - which the Moon NEVER gets to that size, of course!  THe Moon remains at it's usual size of about half a degree, but of course, the media uses telescopic lenses, etc, to blow the Moon up to a never possible size!

It is extradinary how this phenomean has taken off!  The term, "SuperMoon" was first coined by an ASTROLOGER, note, not an astronomer, way back in 1979, but the media only caught up with it in 2011!  Ever since then, this "SuperMoon" rears it's ugly head every year, or less!

I found, however an 'early' version of it in the Moon of December 1999, which was said to be the closest and biggest, but the media had not yet found the term, "SuperMoon"!  They did not pick up on it until March 2011.  (presumably all of the previous "SuperMoons" went unknown, unacknowleged, and unloved by anybody!)

The "SuperMoon" is entirely a media construct - astronomers know them as "Perigee" Moons.  Admittedly, these ARE slightly closer to the Earth, and slightly bigger, but the human eye is unlikely to notice this, as you cannot compare a 'normal' Full Moon, with a "SuperMoon"!

The only way they CAN be compared is by somebody taking an image of a 'normal' Full Moon via a telescope, one month, at a given magnification, and later taking one of a "SuperMoon" at the same magnification.  Then, the differences in size of the "SuperMoon" are far more obvious!

Most people tend to confuse the "SuperMoon" with the "Moon Illusion", instead.  This Moon Illusion is where a Full Moon close to the horizon always appears much larger than the same moon, high up in the sky.  The reason for this illusion is still not fully understood, but it is assumed to be to do with the human brain and eye, 'seeing' something near the horizon, as bigger!

This same illusion will make the Sun larger, as well as constellations, too!

However, the "SuperMoon" nonesense will go on, for the foreseeable future!  In the meantime, astronomers  have the hassle of having to  field questions from the general public about it - something that every observatory and amateur astronomer dreads!
The only advantage of it, is that it might get newcomers  interested in astronomy - even if it is for entirly the wrong reason!

Gary Walker - Results of Cataract Operation


As I said, I was waiting for a clear night, in order to see how my left eye now performs!.  Orginally, for a couple of nights I was seeing coronas around street lights which did not auger well for me looking at bright stars and planets via my scope!  However, these have now gone!

Last Night (November 16th), the sky cleared, and I got out my 8" SCT, and binoculars for the Field Test!

With my naked  left- hand eye, I could now see stars in the Pleides star cluster!  I could also see naked eye  stars with my left eye (beforehand, of course, I couldn't).

With my telescope, the views via both my left eye and right eye, appear more or less the same now!  I did think that my left eye view showed a 'softer' view than my right eye, with slightly dimmer stars,  so the right eye still seems to be slightly better!  Also the focus of my scope does not have to be adjusted for viewing when using either eye (of course, it did before).

With Binoculars, the 10 X 50 pair are now sharp again (up to recently, they appeared to be fuzzy, due to the effects of the left eye -( see an earlier post I wrote on it).  However, if using either eye for looking via the binoculars, the focus is substantially different for each eye (although as stated above, not in the telescopes!).

Remember me aying that the Sun appeared distorted when lookin via eclipse glasses  before - well now it dosen't!


Thus, I was well satisfied  with the results!


I looked at the variable star, Mira, and it was very slightly brighter, than a magnitude 9 star, close by it ( a few weeks ago, it was fainter), so Mira must be starting to brighten up again.

Gary Walker - The effects of my Second Cataract Operation

I am sure that all in the Society, have been hanging on by the seat of their pants,  to see how my latest cataract operation went - I had it last Monday (November 13th).

Well, I managed to look at the Sun, today (November 15th),  and saw that my left eye, where I had the operation, was  as clear as my right-hand eye, now!  Also, I did not have to refocus either my 8" SCT or my SolarMax  40 Scope, anymore!  Before this operation, the left eye showed fuzzy images, and I had to change the focus of the two said scopes fior my right eye, instead!

I had had to adapt to using my right eye, rather than the left eye (which has always been my 'telescope eye').  Now, I will have to get used to going back to my left eye, rather than the right eye!

I have not yet managed to observe night sky objects, to test out the performance of my left eye, on that, yet, so I will report on that when the weather clears!

I saw in a book that only 6% of people my age (I am 55) have suffered cataracts, so I was unlucky, as they are usually far more common in older people!  My other operation - in my right eye was in the Summer of 2015..  After that one, I was suddenly aware that I could see stars of the Pleiades. 


Gary Walker - Losing Astronomical Equipment...

I saw in this month's "Janus", that Stephen had written in his "Tales from a Back Garden Observatory", about losing items from his telescope!


I can certainly sympathise - Brother, I feel your pain!  This is because I can often (temporarily) lose items after observations!

One classic example, was when I observed the June 2012 Venus Transit.  I had taken my 60mm refractor down the road, and over the fields, some hundreds of yards from my house.  On returning to my house, after my sucessful observation, and was packing my scope away in my shed, I found that I could not find one of the eyepieces for that scope!  I hunted all along the shelves in my shed  (as it is full of papers and astronomical stuff) but could not find it!  Then I feared that I'd dropped said eyepiece in the grass over the fields, so I went BACK to the fields and tried hunting around in the long grass for it!  I could not see it, although if it had dropped in the long grass, there would probably be little chance of doing so!

Then I returned home, and back to my shed.  THEN, I found the 'missing' eyepiece about where I had first tried looking for it on the shelf!

I keep my eyepieces in a metal eyepiece box, with special holes in a felt lining for them.  I always put the same eyepieces in the same holes/places, so that I can easily tell which eyepiece is where, and not have to check each eyepiece to see what focal length it has! Thus, I can take out certain ones that I want!  I have a total of 8 eyepieces (although I never use ALL of them, in an observation - I may use 4-5 eyeieces, or less!).

It is, of course, when you pack up, that you suddenly realise that you can't find something!  Often, eyepieces will drop on the lawn, and in the darkness, even with a torch, it can be hard to find them!  Even worse are pens - I am always losing biros, as they are so easy to drop!  They must be about the most irritating objects that anyone has to deal with, in life, apart from keys!  Often, I will find a biro half-hidden inthe grass, and sometimes, they only turn up in the daylight, when visibility is far better!

On finishing an observing session, I make sure that the same eyepices go back in the same recepticles in my box. Then, it is far easier to tell, if (or rather, WHEN!), something is missing!  Eyepieces can also be forgotten, and left in my coat pockets, too!

I also, often find the plastic eyepiece covers dotted around the lawn, on the next, or subsequent days, although at least as they are plastic, they won't be harmed by the rain!  I found one of them, the other day, half hidden in leaves, which had been missing for a week or so!

Gary Walker - Latest Observations

Yesterday (October 26th), it was uncharacteristically sunny and fairly clear, so I had a try for Venus at lunchtime!  I found it via my scope, fairly quickly.  It appeared round in phase (it is actually 94%) and fairly small (it is of 10.5' arcseconds in size).  This is nearly the furthest (and thus smallest) that Venus gets from Earth. At 62X magnification, it did not appear much larger than a pinhead, but it was fairly 'large' at high magnifications.

Venus, however, is not that small, when you compare it with Mars, which is presently of less than 4'arcseconds, only, in angular size!  It is now 7 months since the last Inferior Conjunction (March 25th).

Late in the early hours, I saw that Mira (in Cetus), was at about the same magnitude as a close (but unrelated!) star - which is magnitude 9.  Thus, Mira must be about magnitude 9, too, at present, and at near it's minimum.  It was last at maximum brightness in early 2017.

The Carbon star, R lepus must also be near minumum magnitude of about 9, too.

Gary Walker - SuperMoon Blues

Yes, I'm afraid it's that time of year again, when the thing that all true astronomers dread, raises its ugly head- the dreaded "SuperMoon" yet again!  The November 4th Full Moon was apparently such a one, as is the December one, too!

The November one is often known as the "Hunter's Moon", or the "Beaver Moon", as it would give light to country folk of old, for their work!

I don't know why the media love the "SuperMoon" so much!  It was only created in March 2011!  Admittedly these Full Moons are a bit closer to the Earth, but not enough to be noticeable, visually!  Despite that, every time, the media is full of dinner- plate sized moons, looming over the landcape - of course these only appear that size due to telephoto lenses or zooms on cameras!  In reality, the Full Moon is STILL only the same apparent size as the Sun - ie. half a degree!

The only time the Full Moon appears larger is when it's near the horizon, and this is a normal event - it is the "Moon Illusion" created by the combination of  our brains and eyes seeing it as larger, when it is low down!  In addition, low altitude often makes the Moon turn a beautful banana yellow, or orange  colour!  I once saw a Red Moon rising over the sea, at Deal, which appeared as if it was a total lunar eclipse!


 Gary Walker – Observing Techniques

After listening to Stephen’s excellent and amusing talk last night, it reminded me of some of my observing experiences.

I keep my telescope in an outdoor shed, so it doesn't need cooling-down time!

In the case of dark adaptation, I just go straight out, set up the scope, and start observing.  I don't actually wait 20 minutes for my eyes to fully adapt, before doing so!  My back garden is fairly dark (limiting naked eye magnitude of about 4.5).  I mainly observe to the South, East, and West, as the sky is darkest there and most of the interesting objects are situated in these directions.  Of course, the North is more light polluted, and also my house and tree blocks the lower half of it, anyway.

I have a street-light outside the front of my house (which, incidentally is NOT switched off by the Council in the early hours!).  The next-door neighbour, has an automatic security light which lights up their back garden (and not to mention, part of mine, when it comes on!).   This is usually when they let the dog out, and annoyingly, it keeps coming on, and then switching off, after a few minutes, but then coming on again, when the dog triggers it yet again!   I suppose I COULD speak to my neighbour (who is quite sensible) but it is not that much of a problem, really!  I can put up a clipboard, over my head to shield it, if my telescope is facing East or Northwards.

I sometimes turn most of my houselights out, but not always (I need some light to see my way), and if me and my scope are pointing Southwards, then my house is to  the back of me, anyway.

For writing down my observations, I often use a wind-up WHITE torch (Yes, I hear you all say, Why?), which would temporarily interfere with my dark adaption.  I do have a red light built into the bottom of my Meade, which illuminates things, but it can be too dim for me to write things down, or to read things.

The trouble is, if I started only observing once I was fully dark-adapted, then of course, my telescope corrector plate inevitably dews up, and I have to stop observing.  This can happen on the worst damp nights after less than an hour.

When I decide to observe, if I decide to observe a number of Deep Sky Objects, I note them down on a sheet of paper as a 'shopping list' of objects.  Then I can tick off the ones that I manage to see, and cross out the ones that I don't.  The only trouble with that is that with some of the objects, I can forget what I was supposed to be actually looking for!  Also, as I've gone through one of my astronomy books or magazines on using GOTO to find said object, only to find that it is too low down (or even worse, not yet risen!).  That is one problem with relying on GOTO, rather than star charts.

One thing that I like about my 8" SCT, is that if an object is very high up, or even fairly high up, I can just sit down, as the eyepiece is pointing low down. It is more awkward, if an object is low down, as then I HAVE to stand up, in order to be able to look down the eyepiece.  This can be a problem if I am watching a star occultation by the Moon, as then, I can feel my back really starting to ache!  But then, I dare not move away, in case I miss the occultation.   The tripod can be adjusted, but I have never felt the need to do that, and it is still on the lowest level.  This also means that the scope takes up less space.

When I used to be observing high up objects with my 60mm refractor, it could literally give me a crick in the neck!

When I've finished an observation on a winter's night, my telescope can be heavily dewed up, all over. On one occasion, I remember, it was covered in white frost!  That shows the mark of a good session of observing!  And when trying to lift up my scope to carry it indoors, I have found the tripod legs, sticking in the white frost of the lawn.

Like Stephen, I never put my lens cover on - I just put the scope back in the shed, and let it dissipate overnight.  I put a huge polythene sack over the front to stop dust sticking to the wet lens.

My garden is fairly secure (as much as it can be!).  However if an object is too low to be seen from my garden, then I take my 60mm refractor out, and over the fields not too far from my house. My big scope is too heavy and big to carry all of that way.  I had to do this to attempt to see this year's solar eclipse!  I only saw a few dog walkers in the distance.  I sometimes, use this option, on the rare instances of low altitude events (such as the 2nd Venus Transit of June 6th 2012, for one!).



Mars and Venus Observations form Gary Walker

Early this morning (October 6th), at c. 6am, I observed the Conjunction of Venus and Mars.  They were about 22" arcminutes apart, which is under half a degree (the Full Moon is about half a degree).

I could fit both planets in the field of view of my 62X eyepiece, and just about, with the 100X one as well.  Of course, Venus was much brighter (and larger in angular size) than Mars.  The two had contrasting colours - the orange of Mars against the brilliant white of Venus.  They also made a pretty sight in my 11 X 80 binoculars, and there was a magnitude 4 star, Sigma Leonis about half a degree 'above' Mars (i.e. to the West of Mars).

Mars has moved around from behind the Sun's glare, and is now visible in the morning sky.  It is now starting to get closer to Earth, in time for the next Opposition on July 31st 2018!

At present, it is almost at its furthest away from us, so consequently its angular size is tiny.  At present, it is only 3.7' arcseconds in size.  It is worth noting that Uranus is of exactly this same angular size, at present.  Neptune is a bit smaller at 2.3' arcseconds in size. Of course, there was no chance of seeing any features on it (although Planetary Imagers such as Damien Peach, probably could).

However, it is still interesting to observe Mars, even when it is at its tiniest, just to see how small it appears!  This is a rare sight, as when it is this small, it is either lost in the glare of the Sun's glow for a long time, so is difficult to observe - and in the case of morning appearances, it is at unsociable hours!

With my scope, the disk of Mars was only barely visible at 62X and 100x – pinhead-sized.  Even at powers of 222X, 333X and 490X, it still appeared small.

The last Opposition of Mars was in late May 2016 - now 1 year, 4 months ago, and now 10 months until the next one,.  Thus we are now over half-way between the 2 oppositions.  I last saw Mars on April 1st 2017 - 6 months ago.

Venus is now about 11' arcseconds in size - about 3X the size of Mars at present!



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