Happy Perihelion for 2014!

While we make a big deal of the two annual equinox and solstice events, most people don’t realize that there’s a point when the earth is closer to the sun than at any other time during the year (perihelion) or as far away as we can get from our local star (aphelion, pronounced “ap-helion,” not “afeelion”). Perihelion is always in the first few days of January in our current epoch; aphelion comes in early July.

The earth’s orbit is an ellipse, with the sun sitting on one of the two foci of that ellipse. Because it’s not exactly a circle, there are times during the year when the earth is a little closer or a little further away from the sun than average – about 3% closer. According to the web site In The Sky (http://in-the-sky.org) the earth was at perihelion at 06:59 EST, Saturday 4 January 2014. This was just before sunrise this morning (which took place at 7:52 AM EST here in Hamilton).

I went out to take a photo of the sun on the morning of perihelion 2014. I hadn’t been following the news, and so was pleasantly surprised to spot the big sunspot on the visible disk (AR 1944) in the camera view-finder.

sun

The sun, photographed 4 January 2014. See below for details.

The photo of the sun above was taken from the LaSalle Marina in Burlington, Ontario at 10 AM EST, 4 January 2014, three hours after perihelion. The large sunspot in the lower left has been designated AR 1944 and is one of the largest this cycle. Taken with a 150-500 mm Sigma telephoto zoom lens and 1.4x teleconverter on a Nikon D7000 body; solar filter was an Orion mylar filter for white light. Conditions were not ideal – a great deal of wind, quite cold, and high, diffuse clouds.

Copyright © 2014 David Allan Galbraith

Free Solar Observing Today at Royal Botanical Gardens

We’re going to hold Royal Botanical Gardens’ third “Solar Thursday” today (29 August 2013) from 12 noon to 1 PM, on the lawn area in front of the main visitor entrance to RBG Centre. Everyone’s welcome to join us for a view of the sun through special, safe telescopes.

If you have a solar telescope you are very welcome to join us in presenting the amazing spectacle of the sun to the public. We like to be “open for business” at 12 noon, so coming a little earlier to set up would be helpful. We have electrical power available if your telescope needs it. We start packing things up around 1 PM. RBG is located at 680 Plains Road West, Burlington, Ontario.

We will be looking through specially-equipped telescopes that filter the bright light from the sun. These filters make it safe to observe the sun’s surface. Remember:

No one should ever look directly at the sun without special, appropriate equipment. Permanent eye damage or blindness may result from inappropriate attempts to see the Sun, or the use of incorrect equipment. We will be using telescopes designed specifically for solar observation, or those equipped with filters specifically made for this purpose.

Once you’re familiar with the equipment and have things in focus, you will be able to take in the sights in just a few minutes! Some nice sunspots are visible today.

Katie

Visitors to Royal Botanical Gardens, 680 Plains Road West, Burlington, Ontario enjoying views of the sun live during RBG’s second “Solar Thursday” event, 15 August 2013.

Copyright © 2013 David Allan Galbraith

Enchanted by the Sun

This summer I’ve been delving into solar studies. Perhaps it’s like the proverbial goldfish not noticing the water that surrounds him, but I really hadn’t paid much attention to our nearest star. Last year I did start to take my own look at the sun, using solar filters on an old 80mm f15 refractor, and that was pretty interesting. Somehow the solar bug has really bit me this year.

I’ve added some equipment to Pine River Observatory this year, and that’s helped. In addition to my Meade ETX 125 Terabeam telescope, which I now have equipped with both a Kendrick Astro Mylar solar filter and a Baader Planetarium continuum filter, I picked up a Coronado 60 mm Solar Max II BF15 Hydrogen alpha telescope a couple of months ago. The upshot of all of that is that I can take a look – and am starting to photograph – the sun at two quite different wavelengths, corresponding to different structures on its surface.

There’s an interesting feedback loop here. As I’ve been able to see the sun for myself, and consider how to take photos, and even explain what can be seen through a telescope to others taking a look, I’ve found that my curiosity has risen. I’ve been reading more, seeking out a deeper understanding of what I’m seeing. That in turn has made my observations a little better, I think, and certainly has meant I’m doing a better job of interpreting for others.

It’s also been exciting to see that there’s a lot happening in terms of science and solar observation right now. Consider these three news items from the past month alone:

  • A new ground-based solar telescope (the New Solar Telescope or NST) at the Big Bear Observatory in California has just started to produce incredible images of the photosphere and sunspots – with a resolving power that approaches 30 miles on the sun’s surface (http://www.bbso.njit.edu/)
  • A new solar observatory satellite, Interface Region Imaging Spectrograph (IRIS) achieved “first light” in July, and is already transmitting wonderful images back to earth (http://iris.lmsal.com/)
  • NASA has updated information available on the progress of the present solar maximum. This event, every 11 years or so, is marked by a peak in sunspot numbers, and represents a reversal in the orientation of the sun’s magnetic field. The present solar maximum was anticipated for 20111 but it’s a little late. The magnetic flip is anticipated between now and November.

These are just examples of the activity around solar observations in the past little while. The more I’ve read, too, the more I want to find out. The sun is quite addictive! More postings to come.

sun aug 2013

The sun’s “surface,” or photosphere, photographed from Burlington, Ontario’s LaSalle Park Marina on the morning of Monday 5 August 2013. This image was captured using a Meade ETX 125 TB telescope equipped with a Kendrick Astro Mylar solar filter and a Baader Planetarium continuum filter. These filters produce a green image that highlights contrast around sunspots and solar granulations. The image is a mosaic of two shots taken with a Nikon D5100 at prime focus, as the image produced by the telescope is larger than the D5100’s APS-C-sized sensor. The image was processed with Paint.net, a free image processing program. Although we might think of the sun as a big ball of hot gas it’s structure is much more remarkable than that. At its core the density is enormous – a liter of the gasses would weight 150 kg. At the surface we can see, as in this photo, the density is less than 1% of that of our own atmosphere at ground level.

 

Copyright © 2013 David Allan Galbraith

 

Solar Thursdays at Royal Botanical Gardens Start This Week!

Would you like to take a look at the sun, just for fun? Are you going to visit Royal Botanical Gardens (http://www.rbg.ca) on Thursdays this summer, or just in the neighborhood? Introducing “Solar Thursdays” – a weekly one-hour chance for visitors to  directly see features on our nearest star, the Sun, at RBG.
Solar Thursdays are a chance to see the sun through specially-equipped telescopes. We’ll be set up from 12 noon – 1 PM in July and into August, weather permitting. Some clouds will be OK, but heavy clouds will mean cancellation. We’ll be on the lawn in front of the main entrance to RBG Centre. There’s also a chance that other local astronomers might join in and bring along their own solar-equipped ‘scopes, too! Our address is 680 Plains Road West, Burlington, Ontario. Parking is free. We hope you’ll visit RBG after your look at the sun.
On Thursday we’ll likely see sunspots and solar prominences.  We’ll also have a solar weather update on hand. This offering is free of charge, and is being presented by RBG staff on their lunch hour.
scope

Visit us on the front lawn of Royal Botanical Gardens Centre, 680 Plains Road West, Burlington, Ontario, for Solar Thursdays! Here a visitor takes a turn looking at the sun with a Coronado 60 mm Solar Max II BF15 H-alpha telescope.

We will be looking through specially-equipped telescopes that filter the bright light from the sun. These filters make it safe to observe the sun’s surface. Remember:

No one should ever look directly at the sun without special, appropriate equipment. Permanent eye damage or blindness may result from inappropriate attempts to see the Sun, or the use of incorrect equipment. We will be using telescopes designed specifically for solar observation, or those equipped with filters specifically made for this purpose.

Once you’re familiar with the equipment and have things in focus, you will be able to take in the sights in just a few minutes.

sun

The sun photographed on 23 July 2013 from the front lawn of Royal Botanical Gardens, by using eyepiece projection and a Sony pocket camera. Several prominences are visible in this view through a Coronado 60 mm Solar Max II BF15 telescope.

We hope to see you there!

Copyright © 2013 David Allan Galbraith

Where To Go From Here?

While I’ve been interested in astronomy for over forty years, it’s only in the past year and a bit that I’ve returned to that interest in any sort of “serious” way as an amateur. I’ve been poking around at various telescope shops, getting to know some other amateurs in my area, and taking a lot of nightscape photos. I’ve even started taking a few photos of the moon and Jupiter with the equipment I have. Now what?

The sky is a big place. A simple calculation gives you an idea of just HOW big it is – and I’m not talking about how deep it is in time/distance. Consider first the moon. The moon is pretty big. It has a surface area about the same size as the continent of Africa, although we only can see about half of it from Earth of course. With the existing small telescopes I have I can make out features perhaps 5 km across if the lighting is right. The surface of the moon is about 38,000,000 km^2 (km^2 means “kilometer-squared or square kilometers) so if I can see half of it (in total) that’s about 19,000,000 km^2. A crater 5 km across has a surface area of about 19.6 km^s – so that little crater is just about 1/100,000 of the visible face of the moon. The whole visible surface is a lot of territory (or lunatory) to consider. Of course, it might be better to consider the visible disk of the moon, not the near hemisphere for a comparison like this. A disk with the radius of the moon would have a surface area of about 9,500,000 km^2, so the ratio would be about 50,000 craters-worth of area to explore. Still a lot! A purist would try this with angles but the answer would be the same as the disk area sketch.

The thing is, the moon is actually SMALL compared to the visible celestial sphere. Our eyes are drawn to the moon at night, but the reality is that it’s only about a half a degree across. The whole celestial sphere, encompassing 360°, has an area of approximately 41,253 °^2 (according to a Wikipedia entry on the angular area of the celestial sphere). The moon’s disk as an angle is about 0.2 °^2 – so it would take 206,000 moons to fill up the visible area of the sky! (The sun as virtually the same angular diameter as the moon – that’s why we can have such stunning total solar eclipses – so the same thing holds. The sun, so dominant in our sky, covers only about 1/200,000 of the visible celestial sphere. From the surface of the earth only about half of the celestial sphere is visible as the sky, and the sun is about 1/100,000 of it).

The moon photographed from Hamilton, Ontario, on 2012 12 19 2125 EDT with an 80mm refractor and Nikon D5100 at prime focus.

The moon photographed from Hamilton, Ontario, on 2012 12 19 2125 EDT with an 80mm refractor and Nikon D5100 at prime focus. Relatively simple equipment can take nice photos – but if you are interested in going further, what’s the next step?

The sky, then, has room for 200,000 moon-faces, and my little telescopes can show me details 1/100,000 of the moon’s surface. It’s overwhelming – and full of rich detail. From massive galaxies to wispy nebulas and sparkling star clusters, space beyond our little solar system is one of the richest treasures in nature. How luck we are that we can actually see it! If our solar system was within a more complex part of space we might not have as good a view as we do. Then again, it’s a fair bet that the more “interesting” places in space are far more risky too. Our fair wee planet has had less than five billion years of life so far, and only a few major boo-boos (like the asteroid impact that killed the dinosaurs – Ooops!).

So, back to the point of this ramble. As a (re)budding amateur astronomer, where do I start? I’m faced with this question because I’m looking seriously at upgrading some of my equipment, and different telescopes do different things. Do I make use of my existing optics and improve my ability to point and shoot, with a better mount and camera? Do I invest in a better optical tube (the actual “telescope” part)?

To some degree a telescope is a telescope. There are some basic characteristics everyone needs to consider when they are thinking about this kind of thing. One of the most important is portability. Like a lot of people, I live in a small apartment; I don’t have a garage or basement for storing large pieces of kit, and I don’t have my own space for a shed or observatory. So, compact and rugged is good. I’m also watching my budget (gulp). And, of paramount importance to me, I want to embark on something of a path in learning astronomy, not just grabbing at big telescopes because they’re cool! (and they are cool, and I’m a telescope geek).

I’m thinking I’ll start in the neighborhood this year, seeing what I can see – and photographing what I can photograph close to home in the “planetary” range – the sun, moon, and planets. This narrows things a bit, and is also a good choice for an urban dweller. Despite light pollution in cities, our own solar system is still quite observable from our sidewalks and parks because the objects are so bright. The existing ‘scopes I have – an old 80 mm refractor and a 130 mm “starter” Newtonian reflector – will do for now. What I need to do is to consider in the short term is what’s under the telescope and what’s attached to it.

Telescope mounts are important and perhaps underappreciated parts of the whole “system.” A heavy, capable mount makes viewing anything much easier. A lightweight mount only has the advantage of light weight. Small mounts shake. If you adjust a small telescope on a light mount it can take five or ten seconds or more for the resulting vibration in the camera to dampen out. So, I’ll be paying attention to mounts.

Cameras are at the other end of the process. There are some things I can do with my dSLR cameras, but the best images today are actually being taken with cameras that are much simpler than a dSLR but are designed to be used with a telescope – and a computer. Derived essentially from webcams, most cameras that work brilliantly for planetary photography by amateurs have small-seeming sensors – often less than a megapixel. They are also specialized in two other ways. They often have a built-in cooler, to help control internal camera noise – and they are often monochrome. Yes, black and white. You can do a lot in black and white, and you can get colour images by taking a series of monochrome images through coloured filters. The image files (often actually captured as short video segments in AVI format) are then processed with some ingenious computer software to create stunning, sharp images. So, I’ll also be looking at a small, specialized camera designed for planetary imaging. By starting with a camera and a sturdier mount, I can get going and will consider upgrading the optics a little later.

I’m also sure that there will be lots of opportunities to peek out past our solar system in the coming year. I’m going to be making visits to observatories, star parties, and other events to soak in more of deep space – and of course to be able to make reports here at Pine River Observatory! And I’ll be spending time under the night sky doing wide-field photography and just wandering around the stallar back-yard with binoculars and a good star guide. There are many lifetimes of space out there to enjoy.

© 2012, David Allan Galbraith