The Best of the Sharpless Catalog

[alanjgreen]

Introduction

I purchased a Night Vision Monocular in April 2018 to attach to my TeleVue eyepieces and use for astronomy purposes.

Initially I purchased an Astronomik 6nm Ha filter (I later switched to a Chroma 5nm Ha filter) to allow me improved views of many visible nebula but I discovered that I now had access to a whole new world of previously invisible (to me) nebula.

I discovered that many of these were in the “Sharpless” catalog and began a journey to see how many of the 313 catalog objects that I could find/observe.

I wrote an article in the Webb “Deep Sky Observer” (Issue 181) detailing my joy and initial efforts to observe the Sharpless objects using my Night Vision Monocular.

Last week, I observed my 303^rd Sharpless object. Of the ten outstanding, one does not exist (sh2-214) and nine and very low on my Southern summer horizon (and will be left for a Greek holiday sometime in the future!) so I am ready to publish my findings in the hope that they may assist others who take the same route in the future.

 

 

Finding the Sharpless Objects

Before you can observe an object, you need to find it and get it into the eyepiece (obvious)…

My main scope is a 20” push-to Dobsonian which I attach to Sky Safari 5 Pro and push to my chosen targets.

I soon discovered that the Sky Safari database only contains 249 entries and a small number of these are in fact erroneous or duplicates. In all, I have had to locate 75 Sharpless objects manually…

I would like to call out the book “The Astrophotography Sky Atlas” by Charles Bracken at this point, as my search would have soon been abandoned if it had not been for this book and its great tables of Sharpless object data (at the back). With this data and the galaxymap online explorer, I was able to use sky co-ordinates to find nearby stars (in Sky Safari) and then hunt around that area to finally find and record an accurate positional star.

Many Sharpless objects are huge and so I also employed a second widefield scope, a Borg 107FL, which I paired with a Skywatcher AZGTi GOTO mount with SynScan handset. As I found the Sharpless objects, I recorded the nearest SAO catalog star and then used this for the GOTO mount to get the Borg107FL on target. Unfortunately, I discovered that the SynScan handset does not hold the full SAO catalog, so once again there was some “on the fly” rework needed to get the nearest SAO that was in the handset identified and recorded!

 

The Best of the Sharpless catalog

Many of the Sharpless objects were underwhelming at the eyepiece (when compared to objects like the Rosette, Gamma Cygni or the Orion nebula) but when you consider how faint and small some of these objects are then there is more to this than just the “visual beauty” perceived at the eyepiece.

However, there is no denying that many Sharpless objects are very beautiful at the eyepiece and in many cases are equal or even better that the better known and more photographed Messier nebula objects.

I am therefore publishing my “Best Of Sharpless” list, it is entirely based on my own perceptions so feel free to disagree with the objects that I have selected, I will not be offended.

My goal is to inspire just one person (who has an Ha filter) to turn their scope to one or more of these objects and for them to observe an object that they have never seen before!

What follows is a data table of 115 Sharpless objects (the best of according to me). For each object the table shows:

• Sharpless Reference,
• Physical Size,
• Scope Used (B=Borg 107FL, D=20” Dob),
• SS Star Ref (An object that I located manually at this star position),
• Goto ref (Closest SAO, NGC, M object for Goto mounts),
• Catalog Name (The more famous objects already have a name)

Here is the raw excel file,

Best Of Sharpless v1.xlsx

If you have an Ha filter then I encourage you to give them a try!

Alan

Edited October 6, 2019 by alanjgreen