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In reply to: Taylor’s telescope
I seem to remember that visual double star measurments were the main use for this telescope, am I correct/ it is a dual reflecting telecope with 12 and 10 inch mirrors mounted in parallel fashion.
Topic: Taylor’s telescope
This telescope from Hanwell observatory was mentioned in another thread
Unusual but Interesting design.
Is it possible to collimate the mirror from the eyepiece end?
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In reply to: another amateur comet discovery
My main telescope can’t get that low so this was using a portable mount set up at the other end of the garden which has a pretty good southern horizon. This plot shows the brightness of the sky background in the frames of this field. I started imaging just before 05:50 when the comet was about 7 deg aove the horizon and there was some cloud low down. The sky darkened a bit as the comet rose and the cloud cleared and then started to brighten rapidly at 06:30 as dawn arrived. My optimum time was between 06:10 and 06:30 when the sky was at its darkest and the comet was around 10 deg up. Astro twilight started here at 05:57 but my sky low down is so bright from other sources that I didn’t see the effect of the Sun until around 30 mins later. By nautical twilight at 06:39 the sky was brightening rapidly.
An interesting article by Christopher Taylor on observing the Apollo 8 booster from the UK 50 years ago
https://www.skyandtelescope.com/observing/stargazers-corner/apollo-8-view/
Robin
Jon Shanklin writes in the latest BAA Comet discussion list:
2018 Y1 (Iwamoto) “Masayuki Iwamoto (Awa, Tokushima, Japan) discovered another comet in images taken on December 18.84 with a 10-cm f/4.0 Pentax SDUF II telephoto lens and a Canon EOS 6D camera. The comet was around 13th magnitude with a well condensed coma. It had been posted on the PCCP as IF032. [CBET 4588, MPEC 2018-Y52, 2018 December 20] The very preliminary orbit suggests that the comet might have been discoverable by a southern hemisphere survey telescope earlier in the year. It then passed through solar conjunction and has just emerged into the morning sky. The comet is probably approaching perihelion in late January at 1.1 au and may then pass 0.2 au from the Earth in early February when it could be 6th magnitude. The preliminary orbit is based on an arc of only two days and should be regarded as very provisional. JPL give the 1-sigma uncertainty in the date of perihelion as 110 days and in q as 1.4 au. It may become visible from the UK in mid January, but will be a morning object until its close approach.” Attached a couple of images, one of the man himself (Iwamoto) and the other his discovery equipment a 10-cm f/4.0 Pentax SDUF II telephoto lens and a Canon EOS 6D camera.
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In reply to: Identifying Lunar Features
Hello Garion
You could also download the free Virtual Moon Atlas for a PC.
https://sourceforge.net/projects/virtualmoon/
You can configure for different views – as seen naked eye, binoculars, or through a telescope with or without diagonal and so on. It also shows the phase and terminator for any date and time you choose. Basically a Cartes du Ciel (or Stellarium) for the Moon.
Hope that helps.
I thought the name sounded familiar when I read the article. It turns out SN2018oh was one of the Supernovae I classified this year.
(The paper mentioned there cites my classification)
There are other papers coming to press on this SN which add to the debate on what the progenitor systems of type Ia SNe look like ( eg the traditional model of accretion onto a white dwarf from a companion star or a merger of two white dwarfs, an alternative which has been gaining support in recent years) Though no firm favourite yet it seems
Robin
In reply to: Spectrum of Comet 46P/Wirtanen
Nice spectra. I tried to collect a spectrum of 38P/Stephan-Oterma last week. The spectrum of the nucleus was basically a straight line and the coma indistinguishable from the sky background spectrum from a part of the sky a few degrees away, (total exposure 4200 secs). On reflection I think I was a bit optimistic, the nucleus is mag 14.5 and the total mag is 10. I wondered if a a short focal length telescope is better for spectra of faint comets. What magnitude does a comet need to reach before it’s reasonable to expect to capture a spectrum with amateur equipment?
Topic: Nova in M31
I spotted a new object in M31 on the 26th November. The Liverpool telescope confirmed a nova spectrum for the object, so far designated AT 2018jas. The magnitude is now about 16.4 so would be a good target for amateur spectroscopy.
Coordinates: 00:43:44.560 +41:27:52.40
When first detected the magnitude was 18.5, so it was caught well before the maximum brightness.
This comparison image shows the increase:
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In reply to: Bresser Telescopes
Thank you Peter, David and Andy. All of your points and facts you’ve raised have been more than helpful, and have really made me think on what I really need, and what I don’t!
I am shying away now from a big refractor, soley because of portability. As I’ve already mentioned I think, I have two big old heavy dinosaurs sitting (in pieces) in my cupboard, that I’m unable to use because of lack of portability. For the record, one is a Charles Frank 6″ F/9 reflector, and the other, an 8.5″ F6 Newtonian, built by AE. So I don’t need to shell out a great deal of money to add a yet another telescope to the cupboard! You’ve all recommended a folded reflector, and with this in mind, I am now hankering towards a good sized Cassegrain, but not a closed tube design, mainly because of dewing on the corrector, and large central obstruction. If funds permit, I’d really like to avail myself of the Takahashi Mewlon 210. It’s a Dall Kirkham design, and the quality is second to none in my mind. I think it will still be portable, but will be on the limit, I understand that, but I want the mount to be substantial. Does anybody have any experience of the Mewlons? I once had the use of a fine Takahashi refractor, over 30 years ago, and I was truly amazed at the quality. I might have to go 2nd hand though 🙂 as I know that we’re talking megabucks!In reply to: Bresser Telescopes
Another point to bear in mind, for the same aperture you will need a more robust mounting for a long tube telescope than for a short tube telescope. Telescope mountings are often overlooked and I agree with David’s comments. A good mounting makes a huge difference to usability and enjoyment of a telescope.
I am not trying to put you off a refractor, as a good refractor is a joy to use. However, the long distance from the eyepiece to the mount will multiply up any small movements in the mount and tripod.
Andy
In reply to: Bresser Telescopes
Hi Bob – I hope you don’t mind me wading into the debate. I have a number of refractors and Maksutovs which I mainly use for visual planetary observation. The central obstruction in the compound telescope does make a marginal difference in image contrast but detail revealed remains largely the same. Where the Maksutov scores is in the physical convenience of using a shorter tube. I don’t use diagonals, much preferring the ‘straight through’ approach, and certainly following a planet when well north of the celestial equator can make for some interesting times, all the more so as I’m no longer in the flush of youth! The refractor I use the most is a 120mm aperture Skywatcher achromat which with the factory focuser changed for the far superior Crayford type, gives crisp, high contrast views of the planets. One area where the refractor will score is the ‘cool down’ time is much shorter, if the instrument has to be brought from a relatively warm environment into a cool one, for use.
In reply to: Bresser Telescopes
Bresser is a German company that is associated with Chinese manufacturer Jinghua Optical Electronics Co. (who also now own Meade), so that probably gives where they are actually made.
One thing that’s not clear from your post, Bob, is whether you are looking to purchase a whole package: mount and telescope. If you are, we should be talking about the mount at least as much as the telescope. The mount of the Messier AR-102 looks too small for the telescope to me, judging by the picture on the tringastro site. If the telescope and mount are separate, for a manual mount, I recommend spending at least ⅓ the budget on the mount. For a GOTO mount, at least ½.
A separate 102mm f/11 OTA is sold by Altair Astro: their Starwave 102mm f/11. This looks different to the Bresser offering, and got a good review from Sky at Night magazine. I’d say a telescope of this size should not go on a smaller mount than the Skywatcher EQ5, or similar. Unfortunately, we may be getting to the point here that you would have difficulty getting this setup up and down stairs to your first floor flat, unless you disassembled it into several pieces each time.
A 150mm SCT or Maksutov would have similar image quality to a long 100mm refractor, but work with a lighter mounting, and the setup would be more stair-capable.
In reply to: Bresser Telescopes
Thank you David. If I did go for a refractor, it would have to be F/11 or above, because of the unwanted CA. I haven’t the funds for a multi element OG, so it would have to be the basic Fraunhofer design. Hence I would choose the Bresser 102mm F/11 model, rather than the 127mm F9.5. However, I’m beginning to get the drift that Bresser’s aren’t too good, and I do want quality, if I can afford it! Being so interested in Planetary viewing, it would be so nice to use a telescope with an unobstructive optical system. I’d go for a traditional Newt, but I have 2 old British built dinosaurs that I can’t use because of lack of any form of portability. Anyway, thank you for your input, and I look forward to your article in the next BAA journal
In reply to: Bresser Telescopes
Thanks for that Peter. I particularly found the CA value interesting and very helpful. A really good point about the use of filters re CA, but at the end of the day I feel it’s a bit of a bodge. Funny that you should mention a short tube SCT or Mak, as the chap at my nearest Telescope dealer suggested that too. However, I don’t feel a long focus refractor would be too awkward and difficult on my stairs, well not at the moment anyway. That of course could change! The other thing that really puts me off re a SCT or Mak is the relatively large central obstruction, that as you know, crucifies diffraction limited objects. Two questions I’d like to ask you though. To the best of your knowledge, do Bresser’s and Skywatchers originate from the same factory? in China obviously! Also, and I feel slightly embarrassed to have to ask you this, but can you clarify an abbreviation you use more than once, and that’s ‘OTA’. It’s obviously Off The something or other! 🙂
Like the big Newtonian behind you! 🙂In reply to: Bresser Telescopes
Personally I’d go for the aperture if it’s within your budgetary and mechanical limitations. Most of the time the image will be seeing limited but the resolution of the larger will be better than the smaller in the brief intervals when the atmosphere in front of your telescope is steady. The extra light grasp will be invaluable if your tastes change and deep sky becomes more important, or if you branch out into fields such as VS and cometary observing.
As for focal length, note that 13*102 = 1326 and 9.5*127 = 1206.5 so the longer focal length is only 10% greater than the shorter.
Added in edit: (127/102)^2 = 1.55, so the light grasp is 55% greater, or roughly half a magnitude.
In reply to: Windows 7 upgrade
Hi Jack,
My set up with the Alpy600 has a ATIK Titan as the guider a SX 694 as the imager for the spectrum. Using Maxim I set camera 1 as the imager using SX Universal and Camera 2 as the auto guider and set Artimis HSC to connect to the Titan. I click on options and using track box size check multi star guiding, Then with the guider setting expose followed by calibrate there will then be series of exposures ending with a red l shape. Then click track. I like to open the graph option. Onc set exposures of at least 1200 secs is accuratly set, Generaly speaking I set Agressiveness at 7. The autosave option allow a series of exposures
It is worth noting the Maxim works without telescope control in my case using Sky X using T point take a series of images around the target noting the slit This will ensure the target star is in frame, up and down buttons will move the scope until it is centered on the slit. At this stage I use maxim to guide as noted above.
FOR SALE: Vixen 80mm f/11.4 achromatic refractor on Great Polaris equatorial mount. Comes with built-in pole-finding telescope, electric slow motions on both axes, aluminium tripod, 20mm eyepiece and star diagonal. Tube has camera mount for piggyback astrophotography. Very good condition. All for £399 o.n.o. Buyer collects; seller is based in Oxford, UK. Please contact Lee Macdonald, leetmacdonald@gmail.com.
In reply to: new visual comet discovery by Don Machholz
Owen. Yes, Andrew Robertson and Peter Carson had a good view through Andrew’s 18-inch telescope at Haw Wood. They commented that the comet was bright and easy.
The latest ephemeris is here using all astrometry I have so far. I’ve done this starting 60 days before now and the positional uncertainties are now quite small. The comet has been at a small elongation for all of this time and was discovered when it was at its largest elongation. This is now decreasing. The comet has a small q (0.39 au) and is brightening rapidly.
Please try to observe this comet at any opportunity.
Nick.
In reply to: new visual comet discovery by Don Machholz
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