Below is the text of my latest observing article. The formatting isnt exact as I pasted from Word.
Surprise me, Sky!
766 Observations in Canis Minor
Introduction
In December 2020 I started a project to systematically observe Canis Minor. I will attempt to describe my motivations, methods and results below.
Background
Over the years I have tried many approaches to observing. They can be divided into two main categories: Random or Organized. Both have merits and have resulted in many satisfying nights under the sky.
Random is basically looking at whatever strikes my fancy, or examining a part of the sky without a plan.
Organized is commonly using a list, or having a particular goal in mind.
In either case there were two main drawbacks, Repetition and Omission. Repetition is observing the same targets, or same part of the sky repeatedly. It’s nice to visit old favorites. Repetition is mandatory for monitoring variable stars. But observing is also about discovery and exploration of the unknown.
Omission is missing out on particular targets or parts of the sky repeatedly year after year.
Let me give you an example. Every fall I spend all my time observing the Milky Way constellations from Cygnus to Cassiopeia. I almost never observe in other constellations like Aries, Pisces, or Pegasus. The visual beauty of the rich Milky Way overhead invites close scrutiny.
Here is another example. Many beginners begin with the Messier List. It’s a fine way to start. But some constellations (Virgo, Sagittarius) have plenty of targets, but many parts of the sky don’t. The observer is introduced to some parts of the sky at the expense of others.
Motivation:
Why Canis Minor? It’s simple, I want to see for myself "what’s there?" This occurred to me one night while observing Lyra. I was familiar with the six bright stars of Lyra. I was familiar with M56 and M57. But the area of the central bright stars was only a small part of the constellation, surrounded by lots of unknown sky. I wanted to discover this unknown sky and make it familiar.
But Lyra isn’t in the sky all the time. As its sinking in the west, Canis Minor is rising in the east. The latter is a strange constellation, with some similarity to Lyra. Both have bright central area surrounded by "empty" sky. Each has a famous bright star. Each is on the edge of the Milky Way, with both dense star fields and sparse. I looked up at it one night and realized, I didn’t know anything about it! It’s small and mysterious. Other than Procyon, what is it known for? In fact, the most observed target was 6 Canis Minoris, an often-used Skymark to find nearby Abell 21 in Gemini.
Method
Over the years I have tried most of the common star atlases for amateurs. The one I use mostly is Uranometria 2nd edition. How do I use it?
A. Working one page of the atlas, randomly.
I had many good nights observing with this method. The downside is it’s too easy to lose track of what was, or not, observed (Omission). I have seen some observers write in their atlases with pencil. On one atlas I used a highlighter to mark observed areas.
B. Working one page of the atlas, observing one gore of RA.
The reason for this is that in references like Burnham’s or Sky Catalog 2000, the lists are organized by strict Right Ascension. But in practice this is difficult with a non-driven scope. When moving north or south, the rotation of the earth keeps the sky drifting west. Correcting for this manually was a chore. (Celestial Coriolis deflection?) I only did this for two sessions before giving it up.
C. Working one page of the atlas, observing one band of Declination.
I finally arrived at this method. It works when I want to observe the area of the entire chart page. It’s much easier to scan East or West without losing my place.
In Uranometria, each chart is divided into bands of 1 degree declination, and bands of right ascension that are 60 minutes wide in the polar charts, then progressively 20, 8, and 4 minutes wide at the celestial equator.
By using the grid, I am able to systematically observe the entire atlas page without skipping significant areas.
(u2K graphic)
I decided to “see what’s there” by covering the entire constellation. Its small and should be easy, right? Well, I was wrong about that. Four months and 765 observations later, I was finished. But no means complete. The sky is so full that there is no way to observe everything – we can only see a representative group. Because there is always more.
This is why lists are good: don’t waste time on blank areas of sky!
For the purpose of “observing” Canis Minor, I observed all 219 “areas” within the constellation boundaries. These areas are grid "squares" formed by the lines of right ascension and declination.
For instance, Procyon is located in the "square" bounded by the vertical lines of 07h 36m and 07h 40m RA, and +05 and +06 Declination.
Uranometria images used with permission courtesy of Willmann-Bell and the American Astronomical Society
Not every area is equal. For instance, on Chart 114, the declination band of 00 to -01 is approximately 1/3 degree tall, while the 00 to +06 bands are all 1 degree in height.
In each grid box, I glance at every plotted star. In star poor areas I scan the blank areas between plotted stars. There are a few grid “squares” where nothing was noted.
For example, the square of 07h56m to 08h00m and +07 to +08, there are seven stars plotted. One is an unlabeled double, the other is variable BU Cmi. There are also three galaxies, NGC 2485, 2491, and 2499. The double is observed to see if resolved at 147x. BU is observed since it’s a labeled variable. The other five stars are glanced at to see if anything notable. The galaxies are observed, and if visible, basic shape and features are noted. While doing this the blank space on the atlas is also observed. Most faint doubles and orange stars observed were too faint to be plotted in Uranometria. This is where Sky Safari is useful as a scope side reference.
Uranometria images used with permission courtesy of Willmann-Bell and the American Astronomical Society.
Most labeled objects are noted, like bright stars, variables, open clusters, nebulae, and NGC / IC / UGC galaxies. I usually don’t attempt these plotted objects: faint MGC and CGCG galaxies, Nova, Quasars, Radio Sources, and X-Ray sources.
In addition to the paper atlas, I use Sky Safari Pro on IPAD/iPhone. This gives me a living, deeper map. I can see information of any star or object, very useful indeed.
Why keep a paper atlas when electronic is available? I’m a book person.
Observing site and equipment
All of my observations were done in my driveway. I live in the far suburbs. The Milky Way is visible with the bright light dome from Richmond washing out the eastern sky. My driveway is on the western side of the house, blocking out the light dome.
My main telescope is an 18" f/3.5 Dobsonian made by Ryan Goodson at New Moon Telescopes. I’ve had an 18" since 2008, and this version since 2017. The main eyepiece is a Nikon 12.5mm giving 147x magnification. Navigation is by Telrad and 50mm right-angle, correct image finder. In 2019 I added a 12.5" f/4.5 NMT dob. With the 12.5 Nikon it gives 129x. Neither scope has Go-To or DSC’s.
I have a small table to hold the Uranometria, iPad with Sky Safari, notebook, flashlight and pens. I use a simple notebook and write down observations as made. I have trouble writing in cold weather with gloves, and later trying to decipher my writing. Each entry is verified later in Sky Safari. One digit off and a star is in a completely different constellation.
Results
Dates and number of observations
Dates # Observations
12-23-2020 44
1-14-2021 21
1-17-2021 46
1-18-2021 50
3-4-2021* 51
3-7-2021 58
3-11-2021 51
3-20-2021** 4
3-21-2021 75
3-29-2021 65
4-2-2021 55
4-3-2021 48
4-4-2021 42
4-6-2021 57
4-12-2021*** 31
4-13-2021 35
4-15-2021 32
Notes:
*The entire month of February was cloudy.
**The night of 3/20 was mostly cloudy. Optimism got me outside. Reality sent me packing.
***April is the last practical month to observe before the constellation sinks into the west. This is why there are fewer observations per night.
766 total observations, minus 20 duplicates.
What did I observe?
Type Number Minus duplicates # Of duplicates
Apparent Doubles 67 66 1
Asterisms 35 34 1
Stars 23 23 0
Doubles 301 290 11
Galaxies 56 54 2
Orange/ Red Stars 173 170 3
Starfields 87 85 2
Variables 17 17 0
Open Clusters 7 7 0
What are apparent doubles? These are star pairs that look like doubles, but are not cataloged as such. Some are wide pairs for binoculars, most are closer. Here are five examples.
Primary Secondary Date Scope Eyepiece Note
BD +05 1813 03/21/21 18 NMT 12.5 Nikon 3 faint companions 16”, 23” , and 43”
HD 57514 TYC 0767-2013-1 1/17/2021 12.5 NMT 17 Ethos 48” PA 246, color contrast
HR 2710 HR 2713 03/11/21 18 NMT 12.5 Nikon wide bright binocular pair, orange and white, 11’ PA 160
TYC 0171-1406-1 03/20/21 18 NMT 12.5 Nikon Tiny triple 9” and 19”
HD 57838 03/11/21 18 NMT 12.5 Nikon apparent quadruple, faint companions 15”, 30”, and 30” away seen with averted vision
Star Names, Separation and PA from Sky Safari, used with permission.
Asterisms
These are groups of stars that have a distinctive appearance. This can be subjective. All checked against the list of asterisms from the former Deep Sky Hunters Yahoo Group. The only one from this list if Streicher 81. Four examples below
Primary Star Other member Date Scope Eyepiece Notes
HD 62723 HD 62900 1/17/2021 12.5 NMT 17 Ethos 4 bright yellowish stars 23’ south of 11 Cmi
SAO 96740 01/14/21 18 NMT 17 Ethos Streicher 81 , center of curling “S” of stars 12’ N-S
TYC 0787-0599-1 TYC 0787-0901-1 12/23/20 18 NMT 17 Ethos V shaped asterism 6’ between these two
?² Delta-2 ?³ Delta-3 03/29/21 18 NMT 12.5 Nikon bright group of four stars plus fainter in FOV
HD 64632 SAO 116111 04/12/21 18 NMT 12.5 Nikon curl of 5 stars 7’ dia
Star Names, Separation and PA from Sky Safari, used with permission.
Single Stars
When observing a constellation, I like to observe at a minimum, all Bayer and Flamsteed stars. Other notable stars are recorded.
Star Proper Name Date Scope Eyepiece Note
HD 64584 12/23/20 18 NMT 17 Ethos lonely star at NE corner of CMI
? Cmi Gomesia 1/18/2021 12.5 NMT 17 Ethos bright blue white star
? Cmi 1/18/2021 12.5 NMT 17 Ethos bright yellow orange star
? Cmi Procyon 03/11/21 18 NMT 12.5 Nikon bright star of the winter sky
HD 68018 04/02/21 18 NMT 12.5 Nikon yellow star in Hydra border G8 +1.0
Star Names, Spectral Type, and color index from Sky Safari, used with permission.
Doubles
I found far more doubles than expected. Doubles plotted on the atlas were observed. Most of the fainter ones like the Baillaud's were found. Occasionally Sky Safari indicated a faint/close pair not seen at first glance. LAF 35 gets a "Zero" observation as only the primary was visible. It was included for its obscure designation. Catalog abbreviations are from SkySafari.
Washington Double Star Catalog Abbreviation Catalog name # Observations
A Aitken 9
ADS Aitken Double Star Catalogue 2
AG Astronomische Gesellschaft 3
ARG Argelander 1
ARN Arnold 1
Bal Baillaud 137
BRT Barton 3
BU Burnham 3
DOB Doberck 1
DOO Doolittle 1
GIC Giclas 1
GRV Greaves 2
HEI Heintz 2
HJ J Herschel 27
J Jonckheere 30
KU Kustner 1
KUI Kuiper 1
LAF Lafreniere 0
MLL Mitchell 1
OL Olivier 1
ROE Roe 3
SCJ Schjellerup 1
SKF Skiff 1
SLE Soulie 20
STF Struve F 21
STTA Struve O 1
TDS Tycho Double Star 1
WDS Washington Double Star Catalog 7
WFC Washington Fundamental Catalog 1
WSI Washington Speckle Inferometer 1
XMI Miret 5
Examples of doubles
WDS name Other name Date Scope Eyepiece Note
A 2744 HD 64687 03/04/21 18 NMT 12.5 Nikon delicate double yellow primary
BU 21 Eta ? Cmi 03/04/21 18 NMT 12.5 Nikon fine white star with faint close companion , amazing contrast in brightness. Second favorite.
BAL 1132 HD 67301 04/06/21 18 NMT 12.5 Nikon very nice unequal , orange and red
J 44 ADS 6143 03/07/21 18 NMT 12.5 Nikon my favorite, red primary with farther close pair
STF 1185 HD 67231 04/06/21 18 NMT 12.5 Nikon very nice close pair
STF 1082 HD 57930 1/17/2021 12.5 NMT 17 Ethos easy dbl
Galaxies
Canis Minor isn’t great for galaxies. Most are faint. For negative observations with a normal eyepiece, I use a Night Vision device held up to the eyepiece to verify a faint or negative observation. Some were repeated on another session.
56 total observations of 47 different targets
NGC 18 observations 5 seen with eyepiece 10 seen with NV 3 not seen with NV
IC 4 observations 1 seen with eyepiece 3 seen with NV
UGC 22 observations 3 seen with eyepiece 15 seen with NV 4 not seen with NV
PGC 12 observations 0 seen with eyepiece 12 seen with NV
These are galaxies seen with normal eyepiece.
Name Date Scope Eyepiece Note
IC 2231 03/07/21 18 NMT 12.5 Nikon faint with averted vision, just E of mag 13.5 star
NGC 2470 03/21/21 18 NMT 12.5 Nikon Seen very faint with averted vison
NGC 2485 03/04/21 18 NMT 12.5 Nikon tiny, round, like at star at first (core of face on spiral)
NGC 2504 03/07/21 18 NMT 12.5 Nikon very small, faint with averted vision
NGC 2508 1/18/2021 12.5 NMT 17 Ethos seen with averted vision w/17 and 12.5 ep,
NGC 2538 04/02/21 18 NMT 12.5 Nikon faint round glow with averted vision
UGC 3760 03/11/21 18 NMT 12.5 Nikon round glow seen fleetingly with averted vison once position known
UGC 3785 03/04/21 18 NMT 12.5 Nikon seen faintly with averted vision once position known with NV
UGC 4228 03/07/21 18 NMT 12.5 Nikon seen DIRECTLY with 12.5 Nikon, 18’ NW of curving chain of stars
Table information from Sky Safari, used with permission.
Orange Stars
I’m fascinated by the appearance of colorful stars against the celestial background. One of my observing challenges is seeing how faint a star where color is still visible. Also comparing visual appearance to given spectral type and color index (B-V). I was very surprised at the sheer number visible. This is very subjective. I noted the ones that caught my attention for color and appearance. An unknown number were observed but not noted.
Orange stars noted by catalog
Catalog Number observed
HD 66
HR 5
SAO 38
TYC 44
Variable 15
Flamsteed 1
Examples
Star Date Scope Eyepiece Note with Spectral type and B-V
HR 3145 04/02/21 18 NMT 12.5 Nikon bright orange K2 +1.2
HD 65604 03/21/21 18 NMT 12.5 Nikon M0 +1.6 very orange
BE Cmi 04/03/21 18 NMT 12.5 Nikon conspicuous orange star C5 +2.7
BK Cmi 03/11/21 18 NMT 12.5 Nikon very nice red star B-V +4.6
TYC 0783-0500-1 01/17/21 12.5 NMT 17 Ethos noticeably orange star +2.6
Table information from Sky Safari, used with permission.
Starfields
These are areas of the sky with concentrated stars, or groups of stars without a distinctive shape. In every instance there was something there that caught my attention.
They are named for a the most prominent star. All checked against the DSH Yahoo Group's list of asterisms, with four matches. This is a difficult category, as positive observations are subjective and observer dependent. Six examples below.
Name DSH designation Date Note
HD 60778 04/15/21 10' dia with two prominent orange stars
TYC 0169-1942-1 03/29/21 7’ dia includes doubles BAL 2275 and 2276
HD 62288 Alessi J0743.0-0005 04/15/21 S shaped group 10’ dia
HD 57562 Pothier 17 04/04/21 7’ dia
HD 57291 HD 57291-Group 03/29/21 13’ dia N-S group
TYC 0168-2389-1 03/29/21 5’ dia group of five stars with four fainter
Table information from Sky Safari, used with permission.
Variables
Uranometria labels a number of variable stars. R and W CMi are notable for their high positive color index (orange color), while BT CMi has a negative value (blue-white color)
Examples
Name Alternate designation Note
R Cmi very orange C7 +2.7, binocular pair with HD 54378, Sep 3’49” PA 69
W Cmi very nice orange carbon star C7 +2.8
YZ Cmi Ross 882 faint orange, M4 +1.6, only 19.5 LY away
BT Cmi blue variable B3 -0.17
Table information from Sky Safari, used with permission.
Open Clusters
Canis Minor lacks showpiece open clusters. Sauer 1 is not in Uranometria, but is listed in SkyTools 3 and SkySafari.
Catalog name Alternate designation date Scope Eyepiece Notes
Do 26 01/14/21 12.5 NMT 17 Ethos not great open cluster around 6 Cmi
NGC 2394 03/04/21 18 NMT 12.5 Nikon busy starfield, looks just like the sketch in NSOG*
Berkeley 78 03/11/21 18 NMT 12.5 Nikon nothing there visual
Berkeley 78 03/11/21 18 NMT NV some faint haze with NV
Berkeley 35 04/04/21 18 NMT 12.5 Nikon very faint around star HD 54699
Herschel 1** ADS 6366 04/12/21 18 NMT 12.5 Nikon lovely multiple or open cluster?
Sauer 1 18 NMT NV not seen NV, unknown date
Table information from Sky Safari, used with permission.
*Night Sky Observers Guide by Sanner and Kepple
**Plotted as ADS 6366 in Uranometria
A couple of years ago I attempted the four plotted planetary nebulae at a dark site. I had no success, so did not attempt them again. Back in 2019 at the 60th anniversary dinner of the Richmond Astronomical Society, I happened to be sitting at the same table as Perry Remaklus. He is one of the authors and publisher of Uranometria. I asked "Why are there planetaries in the atlas far beyond the reach of amateur observers?" I don’t remember the exact answer, but U2K includes all the known planetaries at the time, for completeness.
What did I learn from all this? The sky is full of obscure visual treats. I don’t recommend anyone undertaking such a time-consuming project. I only want to encourage observers be receptive to what the sky has to offer.
John Raymond
Richmond VA
10 Oct 2021
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