Introduction to Calcium K Viewin

Whilst the hydrogen alpha emission line is the primary one used for solar viewing, there are a finite but large number of others. Some are well known to nighttime deep sky specialists, such as hydrogen beta. However, after hydrogen alpha, the next most useful light for solar viewing is calcium K. This reveals a lower, cooler region of the solar chromosphere than hydrogen alpha light. You can view a network of ionized calcium emissions that result from solar cells sweeping through the magnetic...

Solar Max 40 Filter TMax Tuner

This is used to allow double stacking of the filter to reduce the PST's bandpass from 1 to 0.6 A. It screws into the thread. Note that it can also be used with the MaxScope 40 to reduce the bandpass from 0.7 to 0.5 A (Figures 2.29 and 2.30). Double stacking is described in Chapter 1. Unlike other Coronado hydrogen alpha telescopes, it does not need to be sent back to the Coronado factory for precise filter matching. SolarMax 40 filter. Photo courtesy of BCF Telescope House. SolarMax 40 filter....

Magni Max Image Amplifier

Magni Max Image Amplifier. Figure 2.45. Magni Max Image Amplifier. It can also be used with a Barlow lens to increase the magnification even further. If you forgive me for being unfaithful to solar astronomy for a moment, I have managed to take successful lunar shots (Figure 2.46), using it to boost the magnification of a Moonfish Group 3x Barlow lens and 15-mm SWA eyepiece to nearly 500x However, the Magni Max and the CEMAX 2x Barlow lens combination did not work with the PST. It...

Double Stacking a PST by Cameran Ashraf

This section gives a more detailed appraisal of double stacking over a period of time than the tests carried out by Philip Pugh. The PST is a remarkable instrument. For its aperture, it provides incredible views of the solar surface and solar activity that astound and amaze observers worldwide. For me, the PST was my first foray into hydrogen alpha viewing. I was hooked The views were incredible - prominences blasting away on the solar limb and the rare light filament snaking its way across the...

Areas of Expertise

As most of my experience has been with the PST, eight coauthors have added information in their specialist areas in the following table. Cameran Ashraf Double-Stacked PST Marcello Lugli Separate non-Coronado filters John Watson Mounting bracket for the PST I would like to thank Springer-Verlag for giving me the opportunity to write this book and for providing helpful guidance and feedback. I would also like to thank my coauthors, Larry Alvarez, Cameran Ashraf, Nick Howes, Marcello Lugli, Jeff...

CaK

For general information about calcium K viewing, please refer to Introduction to Calcium K Viewing section in Chapter 1. Although I have been observing the Sun in hydrogen alpha light since the mid-1980s, I have never had the opportunity to view it in calcium K light until August 2005 when I purchased one of the first production Coronado CaK 70 telescopes. I had first heard about calcium K filters from Del Wood of DayStar Filters Corp., who was the only supplier of calcium K and sub-angstrom...

Other Coronado Solar Telescopes

PST is the entry-level telescope but many are available with an aperture of up to 90 mm (Figures 4.1 and 4.2). As with nighttime telescopes, the price increases with aperture. Tube assemblies increase in price roughly as the square of the increase in aperture but the extra cost of mounting makes the larger apertures progressively more expensive. All telescopes use an achromatic objective lens made of BK-7 glass. The terms SolarMax and MaxScope for these telescopes appear almost interchangeably...

Mounting the PST on a Camera Tripod

Using a budget camera tripod from high street stores is OK for purely visual use, but it is not particularly steady for photographic use. However, I have managed to take some full disc solar photographs using this method, especially when traveling abroad with the PST, when it is not practical to bring a heavier mount tripod combination. For many types of camera tripod, it is unsuitable for use when the Sun is greater than about 30 above the horizon. Depending on the camera tripod, this setup...

Observing Tips

Most of the observing skills you may have learned from nighttime astronomy are valid for solar hydrogen alpha (or calcium K) viewing. On one hand, it is harder because polar alignment is much more difficult without the Pole Star being visible but, on the other hand, there is no scrambling around the ground for loose screws or dropped accessories and lens caps that you get from dark site observing Precise polar alignment of an equatorial mount is not as necessary as for nighttime deep sky...

Capabilities and Limitations

Indeed, it would be an obvious statement that the MaxScope 60 is better than the MaxScope 40 and the PST because of the increased aperture. It is a bit like saying a 90-mm refractor will show more stars and more planetary detail than a 60-mm refractor of similar quality. There is the key in that they can be compared directly because they are the same design. Ask any nighttime astronomer whether a 1.5 times aperture jump is worth the extra money and do not expect to hear a no. The MaxScope 60 is...

Using Other Accessories

The Coronado MaxScope 70 takes eyepieces with the standard 1.25 inch (31 mm) fitting. This allows a huge variety of eyepieces and accessories to be used. The short answer is that most of the nighttime eyepieces that you use are suitable for use with it. As a general rule, Plossls are the best for purely visual use, whereas LER eyepieces are better for astrophotography. The practical magnification limit does not appear to be significantly higher than the MaxScope 40, despite the larger aperture....

What Hydrogen Alpha Viewing Is

Despite its official designation as yellow dwarf, the light emitted by the Sun is generally thought to be white. Indeed, through a suitable filter or via solar projection, the solar image does appear white. As we know from our schooldays, white light is really a mixture of several different colors, as can be seen in a rainbow. What we are not taught at school is that there are not just seven colors of the rainbow that make up white light there are actually thousands of different wavelengths of...