Observing & Imaging Dark Nebulae

Observing and imaging dark nebula is an interesting deviation for most amateur astronomers as we are trying to detect the absence of light - just the opposite of our normal pursuit. Dark nebulae are clouds of dust that obscure light from objects behind them. We have known about dark nebulae for quite some time, but they still remain somewhat enigmatic.

Both America's Astronomical League (AL) and Canada's Royal Astronomical Society (RASC) have observing programs for Dark Nebulae, and each plan is available in the Deep-Sky Planner Plan Library. Each program has very helpful information available to help with observing. See https://www.astroleague.org/al/obsclubs/DarkNebulaeClub if you are pursuing the AL program, or the RASC Observer's Handbook if you are pursuing the Canadian one.

The objects in these plans typically come from E.E. Barnard's photographic survey of dark nebulae (1927), or from B.T. Lynds' more recent survey (1962) based on the Palomar Observatory Sky Atlas images. These catalogs list size estimates, and the Lynds catalog includes a ranking of darkness - again note that magnitude data are not applicable!

Horsehead Nebula
T.A.Rector (NOAO/AURA/NSF) and Hubble Heritage Team
(STScI/AURA/NASA)

This is a particularly favorable time of year to observe dark nebulae as many lie along the northern hemisphere's summer Milky Way. Although many lie in the summer sky, dark nebulae are visible throughout the year. For example, B 33/LDN 1630 - the Horsehead Nebula - is visible in northern hemisphere's winter evenings. To observe dark nebulae successfully, you need a very dark sky and very well dark-adapted eyes. Some objects can be observed with binoculars, but most require a telescope. The Great Rift in Cygnus and Aquila can be observed with the unaided eye.

Observing dark nebulae can be a nice change of pace from observing bright nebulae, galaxies and clusters. Why not give them a try using one of the observing plans available from the Plan Library?

Binocular Observers: an under-served community?

Binocular observers seem like an under-served community of astronomical observers. Imaging and observing with telescopes receive much more attention, even though binoculars are regularly mentioned when new observers ask 'how should I start?'

With that issue in mind, Knightware has produced observing plans from Phil Harrington's monthly Binocular Universe column on CloudyNights.com for over a year. Each plan, and a compendium of all 2013 plans, are available to licensed users of Deep-Sky Planner 6 in the online Plan Library (http://knightware.biz/community/loginfm.php).

In each article, Harrington describes several objects visible during the month, and he provides a star chart to accompany the article. Objects are visible to northern hemisphere observers, and many are also visible to southern hemisphere observers. For objects that are described in his book, Touring the Universe Through Binoculars (Wiley & Sons), he provides a page number reference. The book is a wonderful reference for binocular observers, so Knightware's observing plans include these page numbers. If you haven't read Binocular Universe, you can find it at http://www.cloudynights.com/. Touring the Universe Through Binoculars is available in paperback and for Kindle.

There is another excellent resource for observers that comes from the UK. Stephen Tonkin publishes a monthly newsletter for binocular observers entitled Binocular Sky. You can find his web page and newsletter at http://binocularsky.com/. Stephen also authored the book Binocular Astronomy (Springer), and he currently authors a column called Binocular Tour each month in Sky At Night magazine. Binocular Tour includes a handful of popular binocular targets that any observer would enjoy. Binocular Astronomy is available in paperback and for Kindle.

If you haven't observed with binoculars lately, why not take them out next time you observe? And don't forget these resources specifically for binocular observers.