Shopping cart
is empty

Archive for September 2019

Celestron RASA Astrographs: Telescopes for Astrophotography

September 20 2019, Stefan Taube

The RASA range of telescopes were developed specifically and exclusively for astrophotography. They are very fast; with a focal length of f/2 they take pictures twenty times faster than a Schmidt-Cassegrain lens at f/10! Because of this a tracking control is not required, and generally fewer demands are placed on the mount!

The RASA 1100 model with a 279 millimetre aperture has already been on the market for some time, and Celestron is now also offering a smaller version, the RASA 800, with a 203 millimetre aperture.

Celestron Astrograph S 203/400 RASA 800

Celestron Astrograph S 203/400 RASA 800

This optical system is also within reach of smaller budgets with the RASA 800, particularly since it can be used with a smaller mount. The illustration above shows the RASA 800 with the AVX mount. This astrograph is optimised for astrophotography cameras with a 22 millimetre field diagonal. The larger RASA 1100 is the better choice for those who prefer to use a DLSR for their photography.

The abbreviation RASA stands for the developers’ names: Rowe-Ackermann-Schmidt-Astrograph. It is basically a normal, routinely-produced Celestron Schmidt-Cassegrain instrument; that is with a spherical primary mirror in front of which is a corrector plate invented by Bernhard Schmidt. Instead of using a secondary mirror to direct the light path towards the Cassegrain focus at the end of the telescope, the camera sensor is incorporated in the prime focus. A corrector assembly comprising four lenses made of especially high-quality glass ensures optimal illumination.

Die RASA-Optik von Celestron

The RASA telescope from Celestron

As the term astrograph implies, RASA telescopes are designed exclusively for photography. There is no option to use an eyepiece. But if you are an amateur astronomer who specialises in astrophotography, you will not see this as a disadvantage, instead you will quickly learn to appreciate the advantages of the RASA telescopes.

High-end telescopes and accessories on special offer!

September 19 2019, Stefan Taube

Our special offer for experienced astronomers, astronomy clubs and educational establishments: more than ten telescopes, cameras and other products from our premium product range at especially-attractive prices!

Celestron Schmidt-Cassegrain telescopes

Celestron CGX-L 1100

Celestron CGX-L 1100

  • Celestron Schmidt-Cassegrain telescope SC 279/2800 CGX-L 1100 GoTo for just EUR 5,690. You save EUR 1,205! First the best offer: with this you get a large but still compact 11” telescope with the largest and currently most up-to-date mount from Celestron. This combination offers you an all-purpose system that is nonetheless transportable.
  • Celestron Schmidt-Cassegrain telescope SC 203/2032 CGX 800 GoTo for just EUR 3,045. You save EUR 650! This telescope is in no way inferior to its big brother mentioned above. It is just as up-to-date and versatile, however it has a smaller aperture. In return it is even more transportable and reasonably priced! 

Omegon Ritchey-Chretien telescopes

Omegon Ritchey-Chretien Pro RC 355/2845 Truss OTA

Omegon Ritchey-Chretien Pro RC 355/2845

These RC telescopes in a truss-tube design, made of lightweight, thermally-stable carbon, are ideal for astrophotography, especially for observatories.  Ritchey-Chretien telescopes combine large mirror optics with an almost perfect image. Two hyperbolic mirrors ensure a large, bright and coma-free image field, in a compact design. The result: perfect stars right up to the edge of the image.

We are offering you the following models with different mirror diameters at very competitive prices:

Riccardi-Honders Telescope from Officina Stellare

Officina Stellare RH

Officina Stellare RH 200/600 AT f/3

  • Officina Stellare Riccardi-Honders RH 200/600 AT f/3 OTA for just EUR 6,600. You save EUR 1,430! The RH telescope design delivers a corrector lens with a very fast focal ratio of f/3, all in a very compact design. This compact design, combined with the lightweight carbon tube, puts relatively little load on the mount: a dream telescope for all mobile astrophotographers, that doesn’t need to remain a dream any longer!

Further instruments and accessories on special offer!

Please take a look at our other special offers. A click on the link will take you to the shop where you will find further details about the product:

All offers are valid only as long as stocks last! Buy now!

125 years of Kowa: TSN-883 Prominar Black Edition spotting scope

September 18 2019, Betty Lux

For its 125th anniversary Kowa presents a new, strictly limited-edition spotting scope model: the TSN-883 Prominar Black Edition. Celebrate with us and secure yourself a piece of sports optics history!

Kowa TSN-883 Prominar Black Edition

TSN spotting scopes are classics from this sports optics manufacturer with Japanese roots. As early as 1894, Kowa began laying the foundations for its expert knowledge in the most diverse fields of science – such as pharmacy, mechanical engineering, textile processing and, of course, in the opto-electronics industry. All Prominar products combine the firm’s accumulated expert knowledge with optimum ease of use and the highest optical quality.

Kowa 1894 – 2019

The unique feature of the Kowa TSN-883 Prominar Black Edition is – as its name suggests – the elegant black colour used instead of the more usual green. Otherwise, it has exactly the same features ​​as the Kowa TSN-883. This means that you also get the scope set with its wide-angle zoom eyepiece and practical neoprene case. All together in a stylish package, which you should secure for yourself right away.

Please note: this special edition is limited to only 500 instruments worldwide, with only 250 of these available in Europe!

Infographic: The Astronomy Highlights of Autumn 2019

September 2 2019, Marcus Schenk

 

In the next three months, from September to November, there are once again some great observing opportunities that we should not miss. A special event is fast approaching: the very rare transit of Mercury across the Sun. But there are also other smaller events to be seen.

The new astronomical infographic “Astronomy Highlights in Autumn 2019” offers you a quick graphical overview. This will keep you up to date and let you know what is happening in the sky.

September:

1 September: Alpha Aurigids

The Alpha Aurigids are a fast meteor shower moving at a speed of 65 km/s, which originated from the comet Kiess C/1911. At their peak on 1 September, around six meteors per hour are visible. The radiant, that is the place from which the meteors appear to originate, lies in the constellation Auriga below the star Capella.

6 September: The Moon meets Jupiter

At a distance of just under 5° the Moon is approaching Jupiter this evening. At dusk we see them as bright objects that are close to one another.

8 September: The Moon meets Saturn

While the Moon was seen near Jupiter two days ago, it is today visiting the ringed planet Saturn. Both celestial bodies approach one another at a distance of 1.5°.

9 September: The Moon’s Golden Handle

This evening we experience the Moon’s golden handle. A fairly rare event that can only be seen during a Moon phase of 83%. We can then discover a closed semicircle of golden light on the dark side of the Moon’s boundary between light and shadow. The reason for this: we are looking at Mare Imbrium and Sinus Iridum crater, which is surrounded by the Montes Jura range. While the crater is still lying in darkness, the Sun rises over the mountain peaks and we see the famous handle.

10 September: Neptune in opposition

Neptune is one of the outlying gas giants of our solar system. At a distance of 4.5 billion kilometres, it takes 165 years to orbit the Sun. Its light is en route for 4 hours and 10 minutes before it arrives at the Earth. During its opposition it is particularly easy to see in Aquarius. At 1am it reaches its highest point, around 36° above the horizon.

20 September: The Moon meets Aldebaran

The waning Moon, which is 72% illuminated, meets Aldebaran, the main star of Taurus, during the night of September 20. Aldebaran is a red giant, a star that has reached the last phase of its life. It shines 150 times brighter than the Sun and is so large that if it were to replace of the Sun it would reach as far as Mercury.

October

3 October: The Moon meets Jupiter

An especially pretty sight awaits us this evening: the Moon meets up with bright Jupiter. This impressive conjunction is worth observing, especially as dusk begins.

5 October: The Moon meets Saturn

In the early evening in Sagittarius, just above the horizon, today you can see a conjunction of Saturn and the Moon.

9 October: The October Draconids

Shooting stars appear to be falling from the constellation Draco on 9 October: this is the Draconids meteor shower. As they dart across the sky they are a fascinating spectacle, even for amateur astronomers. The radiant is located near the star Draconis. Draco is a circumpolar constellation, therefore the radiant lies at an optimal visible altitude in the evening sky.

12 October: Amphitrite in opposition

Amphitrite is a sea goddess in Greek mythology and is married to Poseidon. In the sky, however, Amphitrite is an asteroid of the main asteroid belt, which is now in opposition. It is 211 million kilometres away from Earth. It is currently in Pisces below the constellation Andromeda.

17 October: The Moon meets the Hyades

The Hyades open star cluster is very old at 600 million years and forms a V-shape with its brightest stars. The Moon visits the cluster tonight. By the way: the star Aldebaran does not belong to the Hyades.

20 October: Mercury’s greatest eastern elongation

Mercury is at its greatest elongation angle of 24°, but we still don’t see it in the evening sky.

21 October: Orionids

The Orionids are a smaller meteor shower with an activity of about 25 meteors per hour. The radiant is located in the constellation Orion near the star Betelgeuse. Although you can watch the shooting stars all month long, the peak is seen between 20 and 21 October.

23 October: The Moon meets Regulus

Today the slender crescent moon can be found at a distance of around 10 degrees from Regulus, the main star in Leo.

28 October: Uranus in opposition

Now there is another opportunity to take a look at distant Uranus: it can be seen all night during its opposition. With a brightness of 5.6 mag. you can see it with binoculars alone, but it is only recognisable as a planet using a telescope. You will find it in the constellation Aries. To find it draw a line from the bright star β Ari to the just 4.3 mag. dim star ξ1 Cet in the constellation Cetus. At the start of the last third of the line to ξ1 Cet, you will find the planet.

31 October: The Moon meets Jupiter

Tonight we see a slender and only 15% illuminated crescent Moon directly next to Jupiter.

November

2 November: The Moon meets Saturn and Jupiter

This evening we see a nice conjunction of the Moon, Saturn and Jupiter on the southwestern horizon.

6 November: Taurids

The Taurids are a two-part meteor shower with just 10 meteors per hour expected. What is much more interesting is that some bright fireballs may also be visible.

11 November: Mercury Transit

It only happens every 13 years: Mercury passes across the solar disc and we can follow this transit live through a telescope. It starts at 13:35 CET, the 2nd contact is at 13:37 CET, the middle at 16:19 CET, the 3rd contact 19:02 CET, finishing at 19:04 CET. Unfortunately we can only observe half of the transit because the Sun would have already disappeared under the horizon. Attention! Always use a suitable solar filter for your observation! Never observe the Sun without one! Observation without a special solar filter is dangerous and will lead to severe retinal damage. Let us advise you.

14 November: Asteroid Vesta in opposition

The asteroid Vesta belongs to the main asteroid belt and was one of the first bodies of its kind to be discovered. After Pallas, it is one of the largest asteroids with a diameter of 516 kilometres. On 14 November Vesta reaches a brightness of 6.5 mag. and so you can find and observe it with any telescope. It is currently in the constellation Cetus. You can find it relatively easily by extending a line from o Tau (in Taurus) about 2 degrees to the west. A star atlas is useful here.

17 November: Leonids

On 17 November the Leonids reach their peak. In addition to the Perseids, they are amongst the most famous meteor showers. There have been years when these meteors fell like raindrops from the sky. This usually happens every 33 years when the Earth collides with the Leonid cloud.

In normal years, the shower reaches a peak of no more than 20 meteors per hour. This year the rate of occurrence is a little lower, with 15 meteors per hour expected.

24 November: Jupiter meets Venus and the Moon meets Mars

In the last days of November there are two conjunctions: the Moon and Mars, and Jupiter and Venus.

In the early morning of the 24th we see a delicate crescent moon, Mars and, a little further below, Mercury. Then the following evening, in the very early twilight, there is a beautiful view of Jupiter and Venus.

28 November: Mercury’s greatest western elongation

Mercury reaches the best morning visibility of the year from 28 November at its greatest western elongation, now it has an angular separation from the Sun of 20 degrees. Through a telescope Mercury appears half-illuminated.

19.10.2019
We ship worldwide
Currency
Service
Advice
Contact
Universe2Go