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Observing in Suburban Skies

  • Malcolm Zack
  • Andrew Gannon
  • John McRoberts
Chapter
Part of the The Patrick Moore Practical Astronomy Series book series (PATRICKMOORE)

Abstract

You can observe from there! Don’t be put off by comments or grumbles from country dwellers or those with vehicles and safe access to dark skies. It is harder to see galaxies, and clusters may not be quite as jeweled as described, but there are methods and techniques to enhance your observing session from wherever you are located.

You can observe from there! Don’t be put off by comments or grumbles from country dwellers or those with vehicles and safe access to dark skies. It is harder to see galaxies, and clusters may not be quite as jeweled as described, but there are methods and techniques to enhance your observing session from wherever you are located.

In this chapter, we cover locational observing followed by specific hints and tips for making the most of the sky.

Making the Most of Your Location

Observing from a Flat or Apartment

Tower block astronomy has two main problems: lighting and restricted views. It helps if you have a balcony or access to a roof area.

Try shielding or turning off lights on the balcony or porch. Keep any room lights, TV screens and computer monitors off because these contribute to stray light. Use blinds or curtains and talk to your neighbors. Hopefully they will understand the impact of light and will turn off or turn away any security lighting or internal lights. If you have a balcony light, consider changing the bulb to a red one to help keep dark adaptation as effective as possible.

Although a balcony may have a restricted view, make the most of the sky area that you can see, especially if you can get above rooftops and the tree line. The Moon will be a good choice for low horizon views.

Carrying a telescope down flights of stairs or using an elevator to the apartment’s gardens or driveway may be the only option for some. In this case, pick a smaller instrument such as a refractor to minimize the number of trips you need, and try to avoid leaving equipment unattended if you can.

If all you can do is observe from an open window, work out what part of the sky you can see and plan your observations and targets accordingly (Fig. 2.1). It may be best to focus your observing on objects such as the Moon and brighter clusters as they move into view. Chapter  5 highlights 30 lunar objects to get you going. There are numerous books on lunar observing that can be rewarding for city dwellers, and images of the Moon across the city landscape can be attractive.
Fig. 2.1

Suburban astronomers can be inventive as well as brave! Loughton Astronomical Society member Doug Flack perches his camera on a homemade extension rod to capture wide field views from his flat in London. (Image courtesy of Doug Flack. Used with permission.)

Wide field views of the night sky are still possible, and learning your way around the stars and constellations can be easier when there is less to see (Fig. 2.2). Dark skies littered with stars can sometimes be confusing, even to experienced and knowledgeable observers.
Fig. 2.2

A view of the winter constellations squeezed between an apartment block and nearby trees. (Image courtesy of Doug Flack. Used with permission.)

Garden Astronomy

Stargazing from your garden or backyard offers many advantages to the suburban astronomer. Compared to trekking out to a park or open field, it is secure and provides room to set up equipment, something to sit on, tables (to put this book on!) and just a few steps from the warmth of the kitchen and that all-important cup of tea or coffee!

During the day, look around the sky and horizons from your garden and determine which areas may present wider views. Are there trees just due south? Can you position yourself so that you can still see the star Polaris if you chose to align your telescope and use GOTO methods? Is there a gap between the houses where a low positioned Moon or planet will be visible? Orientate yourself to the cardinal points of north, south, east and west and determine where your major town or conurbation is. That is where the familiar ‘orange bowl’ of light may appear at night.

Look across at neighbors for any lights from windows or security lights that may shine across your line of sight from certain locations in your garden. Where are the street lamps positioned? Are any placed behind trees? These may be partly shielded during spring and summer, but after the autumn (fall) their impact will be greater.

Consider if there are any natural light shields. Positioning yourself alongside a fence or line of trees may restrict some of the view, but these may be tall enough to block out some lights and protect from the wind. Then repeat the exercise at night, even if it is cloudy. This will help identify preferred spots for different objects. On one occultation of the planet Saturn by the Moon, for example, author Malcolm Zack was able to observe the whole event from one extreme edge of the garden over the western horizon, whereas from his usual favored spot the Moon would have sunk below a line of trees well before the end of the event.

Check where the glow from towns is greatest and where the sky appears a bit darker. You may not be able to see everything, but most objects move in and out of favored areas, so you will get an idea of what is possible and when.

Dew is often a problem that requires dew bands and power to heat these to keep dew from forming on the lenses or mirrors. Some observers use portable power packs such as the Skywatcher or Celestron brands, which will usually provide several hours’ power on a single charge. (See Chapter  3 for a discussion on how to use dew bands.) Others may use household power from an external power socket or by running a lead through a window or door from inside. Only use equipment that is designed to be used outdoors and has the appropriate safety protection. It is very important to note where your leads lie and provide some protective cover to avoid tripping over them in the dark.

Observing from your front garden or driveway is also an option and may be the only way you can see objects that are otherwise hidden from your back garden by your house! Just be aware that this may not be as secure so don’t leave your instruments unattended if you are on a busy street. However, you may well attract interested passers-by, and this can turn into an enjoyable and social evening!

Backyard Observatories

Some readers will be fortunate enough to have or have access to a home-built observatory. Such observatories range from adapted garden sheds to professionally constructed domes (Figs. 2.3, 2.4, 2.5 and 2.6). Sometimes a shed is a more favorable option, as its contents will be less obvious to casual passers-by. Observatories with roll-on/roll-off roofs provide all the flexibility of the garden lawn with the addition of storage, protection from wind, some protection from the cold of night and usually require just a short period of setting up before observing begins.
Fig. 2.3

Positioning your observatory – a battle of lights, horizons and garden plants! This observatory is sited at the top of a sloping garden and accessed by a series of steps. The side panel drops down to provide a good southern horizon, and the roof partly blocks a very annoying and inconsiderate street lamp! (Image by Andy Gannon)

Fig. 2.4

Even a small shed can be a practical and inexpensive solution to protect against the elements. (Image courtesy of Dave Gill. Used with permission.)

Fig 2.5

A roll-off roof 3 m by 2.5 m (10 ft by 8 ft) observatory is sited in the north-west corner of the owner’s garden. This affords better views to the darker northeast section of the sky and is only partly impacted by the wire fence. The tree to the west has since been removed, revealing more of the light dome from London positioned south and west. (Image by Malcolm Zack)

Fig. 2.6

The interior of the observatory with the open roof, showing nearby fencing. (Image by Malcolm Zack)

The location of your observatory will be a crucial decision. As with lawn-based positioning, determine the most advantageous part of the sky and be prepared to make some compromises over horizons, rooftops and street lamps. The walls of your observatory may create an artificial horizon, too.

Observing in Town and With Others

Observing with others can be the most enjoyable part of astronomy and is possible even in the world’s largest cities. The Baker Street Irregular Astronomers meet monthly in the center of London’s famous Regent’s Park, just north of the absolute center of the city. Dozens of visitors of all abilities flock to ‘The Hub’ with a variety of instruments (Fig. 2.7). Their Facebook page updates members on observing meetings dependent on weather conditions, and is used as a means of sharing images, observations, alerts and advising new joiners. Members observe the Moon, planets and many of the objects listed in this guide.
Fig. 2.7

The ‘Hub’ in London’s Regent’s Park at dusk. If you can observe from the center of London, you can observe from practically anywhere! (Image courtesy of Richard Deighton. Used with permission.)

Lights and buildings present the same problems, but it is possible to move away from the brightest of these to comparative darkness. We would always recommend, however, that if you choose parks or open areas in towns and suburbs, you do this accompanied by a friend for your own safety. Do be careful if you are on your own with attractive and expensive-looking equipment!

Holidays and Hotels

Taking a vacation in warmer climes can also present an opportunity for town dwellers to pursue objects that are lower in their home skies. However, popular tourist destinations can be among the worst offenders for light pollution. Hotels will have many lights on for guests as they party into the early hours. For the traveling astronomer with a family hoping to get a few new views for an hour or so, this can be a bit disheartening, but our tips below will help mix sun, sea and sand with the stars:
  • Travel light. Take a small short focal length refractor or a pair of binoculars. Many of these are light enough to be fitted to a small portable tripod, and binoculars can be fitted with an L bracket. They can be small enough to be transported as cabin luggage.

  • Tour the hotel and its gardens. You may be able to find an interesting perch with a good horizon that is shielded from the lights.

  • Check out the beach but keep safe if you go there. It may be darker there but you can be at risk if it is deserted.

  • A light tripod set-up is easy to move around.

  • If your room has a balcony, consider some of the tips from our apartment section. Just make sure your eyepieces don’t get knocked off and end up in the swimming pool below!

  • If you have rented a villa or a cottage, you may have lower light levels and may be able to block out or turn off nearby lighting.

  • If you have the requisite solar filters, daytime astronomy can also be fun while on holiday, but limit access to the eyepiece if there are lots of non-astronomers around. The Sun is clearly visible for suburban dwellers. Due to the specialist nature of solar observing and the many excellent books on the subject, we have not included our nearest star as an object for detailed examination in this book , but we do outline the basics of solar observing in Chapter  8.

Making the Most of the Sky

Finding your way around the sky in heavily light-polluted towns and cities can be a challenge, and finding deep sky objects in those skies even more so. In such skies, one is often limited to seeing the brightest stars unaided (often just those down to third and fourth magnitude), which means that all but the brightest constellations such as Orion and Cygnus can only be partly seen and as a result appear indistinct.

Being in such light-polluted skies, though, should not be seen as an impediment to enjoyable astronomy, and many worthwhile objects can still be well seen. When you are familiar with the night sky then star-hopping is often the quickest way to find many objects and will save you a lot of time when you want to have a quick observing session.

Starter Objects

The objects you should start with and learn first are the names of the brightest stars and where to find them, typically those down to second magnitude. A good place to start is with Polaris, so you can always find north, and then the bright stars of the Summer Triangle (Altair, Deneb and Vega) and the Winter Triangle (Betelgeuse, Procyon and Sirius). It is worth having a knowledge of the whereabouts of the bright naked-eye planets. These are often easy to find, as at their brightest, they are the first to appear in the twilight. The planets do move through the sky, however, so it is worth checking their current location using planetarium software or apps. (See Chapter  7 for a discussion and review of popular software and apps.)

Next move on to some of the naked-eye brighter double stars covered in this book, such as Albireo, and Mizar. The best objects to follow on from these are probably some of the brightest open clusters such as M45 (the Pleiades), which can be seen with the naked eye even in urban skies. (M45 is SG15 in Chapter  4 of this book.)

Which Equipment Helps?

Chapter  3 details some of the equipment used to compile this book and the different types of telescopes and mountings available. When few stars or constellations are visible, some of the most useful tools to help you find your way around are those that provide a wide field of view . Binoculars fit the bill best here, and 8x42 and 10x50 instruments will help you to pick up otherwise hidden stars.

A good starter telescope for star-hopping is one with a relatively short focal length of 500 to 1,000 mm, so short tube refractors and Newtonian telescopes are worth considering. Ideally, such a telescope will provide a 2 to 3 degree field of view , with a low power eyepiece giving 20 to 30x magnification. It will probably be easier to line up targets and move your telescope quickly with an altazimuth mount rather than an equatorial mount (Fig. 2.8).
Fig. 2.8

Jonathan Daniels, LAS member who regularly demonstrates star-hopping, with his altazimuth mount supporting a wide field refractor for finding and locating and a larger, long focal length Schmidt Cassegrain telescope for higher power and more detailed views. Note the red dot finders mounted on each. (Image by Andy Gannon)

Fig. 2.9

When it is cloudy, even the best techniques will not help! A cloudy London horizon from Regent’s Park. (Image courtesy of Richard Deighton. Used with permission.)

Some observers prefer to use a red dot finder to locate a target because it helps to see as wide a field as possible. A useful combination would be to pair a red dot finder with a relatively inexpensive 8x50 right-angled finder that provides a wide field combined with the ability to see fainter objects in the surrounding star field.

The next key area of equipment is a high-quality star atlas. Along with this guide, there are numerous books to choose from plus many software programs and star charts.

Star-Hopping: Triangles, Squares and Diamonds

An effective way to begin to find a deep sky object that cannot be seen with the naked eye is to locate a star or several stars nearby you can see. Then visualize lines from those naked-eye stars to the object you are looking for. Using the charts in this guide will help. Alternatively, imagine two visible stars sitting at the two points of a triangle, where the object you are seeking sits at the third point. Using a red dot finder can help to identify these points. (See Chapter  3 for more on red dot finders.) Next either use a finder scope, which will show many brighter deep sky objects faintly, or begin using the telescope with the lowest power eyepiece available. If you can’t see the object, sweeping in a spiral moving outward should eventually bring it into view.

In addition to the techniques outlined above, stars can form other memorable shapes such as squares, trapeziums or diamonds. Use the shapes identified in the charts in this book to help you locate that same shape in the instrument’s finder. This should help you find the target object in the eyepiece of the telescope. Some stars form useful markers on the way, others just snake their way like a roller coaster (switchback) towards the object. Our charts and guides suggest some of these, and you may well develop your own directions and marker stars as you get proficient.

Understanding Field of View and Degrees

In this book, the directions and star hops will frequently define distance in terms of degrees and field of view (FOV). From one side of the sky to the other is 180 degrees. From the horizon to the zenith directly above you is 90 degrees. Moving from one star or object to another can be measured in the same way. If you hold your fist out at arm’s length, that fist usually covers about 10 degrees. An outstretched hand covers around 20 degrees from thumb to fingertips. Translated onto the sky, if you look at the two pointer stars in the Plough (or Big Dipper) that point to Polaris, these two are approximately 5 degrees apart. In comparison, the full Moon covers just half a degree!

When looking through binoculars, your FOV will be narrower because you have magnified or ‘zoomed in’ on your view. Low power binoculars such as 6x30, 7x50 or 8x42 typically have a 6-7 degree FOV. This reduces as the power goes up. The 10x50 normally shows 5 degrees, whereas this reduces to 4 degrees at x15 or no more than 3 degrees in say a 20x80 pair.

When looking through a telescope the FOV depends on the magnification and type of eyepiece being used. Some eyepieces have their apparent field of view (AFOV) marked on their side. AFOV can range from the relatively narrow orthoscopic and Plossl eyepiece designs (40 to 50 degrees AFOV) up through wide field designs that may go from 68 degrees to as high as 82 or even 110 degrees. The actual field of view you will see in your eyepiece will depend on the magnification your chosen eyepiece provides in your telescope , which in turn depends on the telescope’s focal length.

For example, let’s assume you have a medium field eyepiece with a 60 degree AFOV, with a focal length of 20 mm and a telescope with a focal length of 600 mm, which is generally considered to be a short focus telescope. The magnification will be 600 mm/20 mm or x30. The actual field of view you will see in your eyepiece will be the AFOV of 60 degrees divided by the magnification obtained, or 60/30, which is 2 degrees. This is equal to four Moon widths.

The same eyepiece in a telescope of 1,000 mm focal length will have a power of 1,000/20 or 50x and a field of view of 60/50, or 1.2 degrees. Hence the higher the magnification the smaller the field of view. However, an eyepiece design that has, say, 80 degrees APOV and 20 mm focal length will give a power of 50x in a 1,000 mm telescope but give a wider field of view of 80/50, or 1.6 degrees. In the smaller 600 mm telescope the same wide field eyepiece will also magnify at 600/20, or 30x, but give a field of view of 80/30 or 2.67 degrees.

FOV is important because if you start looking for objects with a high power, it can be difficult and frustrating. Always start with a low power, red dot finder or finder telescope, or use a pair of binoculars. Keep practicing, and when you have the object in view, then increase the power if necessary. Low powers also keep the object in the field of view for longer if you are not using a driven mount.

Imaging

This guide is chiefly about visual observing, yet all of the images have been taken by club members from suburban locations, so we include a section on how this was achieved. There are many excellent books, guides and articles on astrophotography; interested readers are encouraged to seek these out and speak with members at local astronomical clubs. Imaging can be quite a challenge, although it is possible these days to take quite impressive shots of, say, the Moon or star fields with modern day smart phones.

Techniques, equipment and software used are described in Chapter  7 and in Appendix A of this book .

Some Helpful Suggestions

Here are some suggestions from our years of observing:
  • Determine what the sky conditions are.

Milky skies or ones with a lot of moisture present will make finding galaxies and nebulae difficult. Go for clusters and higher contrast objects in this instance. You may find a higher magnification darkens the view in the eyepiece and helps improve the contrast.

Nights where the stars twinkle, even if they are quite some way up, suggests rapid movement of the atmosphere at high altitudes. This can reduce the quality of ‘seeing’ as the high winds passing between the ground and air will affect the image. In these cases, higher magnifications are not effective, and you may find a medium power view outperforms a higher power. The view appears sharper and details a bit clearer, although smaller than at the higher magnification. For observers in the United Kingdom and other parts of northern Europe, the position of the jet stream, which travels from the Gulf of Mexico across the Atlantic Ocean, exerts a major influence on the weather. The jet stream’s high-altitude wind speeds and its position can have a dramatic effect on image quality.

Sometimes hazy nights are best for lunar and planetary observations. (See Chapters  5 and  6.) The haze may affect views of deep sky objects such as galaxies and faint clusters, but it is often associated with still conditions and less turbulence, resulting in periods of very steady seeing.
  • Keep an eye on weather fronts and impending rain.

It’s annoying when these are happening, but after rainfall, especially after a storm, dust and particles that were in the sky have been washed to the ground, and the sky appears more transparent than before wet weather.
  • Generally, pick objects that are higher in the sky.

A thinner atmosphere will help improve the view. Objects will always be harder to see well when lower down, especially in the sky glow and domes of light formed by local light pollution and nearby cities. Starting from around 30 degrees of altitude means most objects are within range and still comfortable to view but are beginning to pull away from the horizon light, and there is less dense air to peer through. Use a star diagonal to reduce risk of neck strain. (See Chapter  3 for an explanation of star diagonals.)
  • Make the image move.

A very faint object can often be encouraged to appear more clearly by tapping or nudging your ‘scope to slightly shake the image.
  • Consider which objects are best for your location.

Towns and cities vary in size, shape, design and levels of light. A location 8 km out from the center of a major metropolis such as New York, Paris or London is still likely to be somewhere in the suburbs. The same distance from the center of a modest conurbation may position you in a semi-rural environment and more favorable skies. From the center of large cities, the best objects in this guide are likely to include double stars, the brightest clusters, the Moon and planets. From these locations, refractor telescopes tend to excel, as do the long focal lengths afforded by catadioptric telescopes, which are covered in Chapter  3. Binoculars will always show you something wherever you are located. As you move deeper into the suburbs, darkness steadily improves, and the fainter clusters and galaxies covered in this book become more easily defined.

Making the Most of You

Keeping Your Eyes in Observing Shape

Your eyes are the final lens through which the light after its multiyear journey finally enters for processing by the brain. Get them regularly checked for general health. If you have glasses, you may still need them at the eyepiece if you have astigmatism, but some may prefer to observe without them to ensure they can see the whole view. Only eyepieces with short focal lengths will present problems for spectacle wearers. Keep them clean. Oil from eyelashes or heat from your breath can make the lens dirty and affect your view, so use a spray or specialized cleaning cloth before the observing session starts and have access to that for use later if necessary. If you are able to wear contact lenses well into the night, this may overcome the problems usually presented by glasses, but as you get tired, they can also impact your visual acuity, and the lenses themselves will pick up eye debris.

Some users may have varifocal glasses. These are not a hindrance, but it may mean positioning your eyes and glasses more centrally to make the most of the view and avoid out of focus or elongated images towards the edge of the field.

Be aware that your eyes have a blind spot, so in some cases it is advisable to move your eyes slightly, to see if that is where the object is hiding. Also, the center of the eye does not have the most sensitive of receptors, so looking off to one side can make a faint object easier to see. This is known as averted vision.

Give Your Eyes a Chance to Dark Adapt

Our eyes gradually adapt to low levels of light by opening up the iris and increasing sensitivity. The whole process takes 30 to 45 minutes, which is why people often remark that more stars are ‘coming out now.’ This is a combination of dark eye adaptation and the sky getting darker as the evening moves on. Dark adaptation, once obtained, will make a real difference to what you can see with the naked eye and through your instruments, but it can be ruined in a flash.

Keeping the adaptation is a real challenge for suburban observers. A bathroom or bedroom light from a neighbor winks on just as you are looking at the cluster a few degrees above the relevant roof! Or a security light flashes into the corner of your eye as it detects movement from next door’s cat. A short increase in brightness should not affect you for too long, but it can take a number of minutes and perhaps up to 20 to regain full adaptation after a prolonged exposure. So, if you do decide to return inside for a while, remember to keep this in mind. To be fair, in the suburbs, high levels of adaptation are hard to attain and maintain because we do not have much control over the local environment.

It rarely matters for lunar observing of course, but if you are still experiencing issues keeping things dark enough, don’t throw in the towel and pack up. Put the towel over your head instead! Sit at the eyepiece and place a hand towel (make sure it’s clean!) over your head to act as a shroud. The effect can be quite significant, and in some ways can detach you from the world around you. It can cause some local heat issues as your breath may collect around the eyepiece, but that is a minor concern. Don’t worry how it may appear to someone looking out of their window – at night all cats are gray!

Keep Comfortable and Warm

For those of us in northerly latitudes, the long winter nights may present the darkest skies but also the coldest environments in which to observe. Cover up – wear several layers of hats, gloves, thermals and boots. In milder seasons or in lower latitudes, you may be lucky enough to observe in your T-shirt and shorts! Wear sensible footwear, though. A summer’s night may tempt barefoot observing, but a stubbed toe on a tripod leg takes the joy away very quickly!

Take Plenty of Breaks

This will give your eyes a rest but also your feet and legs. As you get tired, it can become harder to see detail. Perhaps spend 20 minutes or so just gazing up and doing some naked-eye observing. Focusing on infinity can be very restful and gives you a chance to review the sky conditions and perhaps re-test your constellation knowledge. Alternatively, cup your palms over your eyes for a couple of minutes. An adjustable observing chair is a worthwhile investment, but a stool or folding chair will do just as well and will help prolong your sessions. There is some argument that drinking coffee or other drinks with caffeine can affect the visual acuity of your eyes and make some fainter objects more difficult to see. However, it’s a personal choice, and the warmth and social aspects of drinking coffee or tea with friends on an observing night strongly weigh in favor. Avoid alcohol though. Even a moderate glass will affect your vision, and it goes without saying that a few beers and a few telescopes in the dark do not mix!

Practice, Practice, Practice!

Our charts and guides are here to help you, but only by frequent observation and re-observation will you learn your own way around the sky and become a true star-hopper! When you have become proficient, touring the sky becomes even more of a pleasure, and knowing your way around and showing others can be immensely satisfying. Knowledgeable observers are often in demand at star parties or society events and public open evenings, teaching others the pathways to the skies.

Copyright information

© Springer International Publishing AG, part of Springer Nature 2018

Authors and Affiliations

  • Malcolm Zack
    • 1
  • Andrew Gannon
    • 2
  • John McRoberts
    • 3
  1. 1.ChigwellUK
  2. 2.Waltham AbbeyUK
  3. 3.Great DunmowUK

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