CMi - massive string of faint doubles

[Mr Spock]

I'm just preparing one of my charts for the 12", this one is for CMi.

I can't help but notice there's a 4-5­° wide band of 10-12 mag stars extending from Procyon across into Mon which are all doubles. Very unusual to see so many all in one place. Fascinating, as someone once said.

[Mr Spock]

The chart I've marked for this area goes from 7^h8^m to 7^h48^m and +03°50 to +10°10. There are 147 doubles within the range of my 12" down to a secondary of mag 12.5 - my limit in the LP I have. 30+ are at or below 1.1" separation; I've marked up 10 0.5" to 0.6" separation as a test for the 12". I've ignored a dozen or more even 11-12 mag doubles of 0.6" separation as there's just no room to mark them!

[Ratlet]

That should keep you occupied for a while!

 

[Mr Spock]

Who would have though a plain looking part of the sky could be so interesting. If people took a step back from small refractors there's so much out there you couldn't possible look at everything. This is only a 10°x7° area of the sky and there's a dozen sessions in there 

[glafnazur]

That's brilliant, thanks Michael. I'll give them a go if ever I get some clear skies 👍

[Mr Spock]

Here's my field map ready to go.

As usual, it has my 4" scope colour coding for separation. Yellow 30.0" and over, green 10.00" to 29.99", orange 3.00" to 9.99", red 1.14" to 2.99" and purple below 1.14"

[Ratlet]

How do you log the ones you've seen?

My head's spinning trying to take all of that in.  Love the colour coding!  I bought some erasable highlighters for something similar, but haven't gotten organised enough to do it yet.

I think I'd get massively lost in that.  I'm hoping to get started on doubles next week if they manage not to update the weather and the green actually stays green.  Got @Ags double book as a starting place.

[Mr Spock]

1 hour ago, Ratlet said:

How do you log the ones you've seen?

I keep everything in Excel. Here's an example of a session from last year:

Region	γ Cyg region
Date	from 20:30 27/09/2022 to 01:30 28/09/22
Scope	Stella Lyra 12" Newt
Eyepieces	42mm LVW, x40, LVW 22mm x69, LVW 17mm x89, LVW 13mm x117, LVW 8mm x190, LVW 5mm x304
Conditions	very good seeing and very good transparency - mag 4.8 in the direction of Cygnus
β 665	A faint and slightly uneven pair near γ Cyg; tight at x190
MLB 21	Too faint, sec not seen - should have been though at mag 12.0
D 22	An easy but uneven pair at x190
TOR 25	Very faint secondary, seems fainter than the published mag
MLB 22	A faint uneven pair x190
OΣΣ 206	A very wide pair x117
SEI 1117	Wide pair in the same field as OΣΣ 206 with a fainter star inbetween
SEI 1115	Wide pair at x190; in the same field as J 129 which was also resolved
TDT 2232	A tight, faint pair at x304
TDT 2233	In the same x304 field as TDT 2232; not as tight but a fainter secondary
Σ 2668	A bright uneven pair in the middle of a group of other doubles - the next five below
SEI 1091	Very wide, uneven pair at x69
SEI 1090	Very wide, uneven pair at x69
SEI 1094	Wide and very easy at x190
SEI 1097	Another wide pair at x190
TDS 1061	Tightest of the group, but resolved at x190
β 661	A very bright orange primary with a very faint secondary, x190
h 2951	A wide uneven pair at x190
Cou 2537	Tight! 0.8" resolved at x304 in moments of steady seeing
Σ 2663	A lovely even pair; looked nice at x117
HDS 90	Faint secondary - mag 12.6, about half the separation of Σ 2663 and in the same field at x117
SEI 1051	Wide uneven pair at x69
SEI 1070	Wide uneven pair at x69
COU 2536	Strangely difficult. Split at x190 in moments of steady seeing
SEI 1078	Another one of these wide, uneven blue pairs that seen to litter this region. X69

[Ags]

So methodical - respect!

[Ratlet]

Excellent.  Thanks for sharing that!

[Mr Spock]

It's also good practice for finding things through star hopping. I pick out something bright, then use the 42mm LVW at 1.8° as a finder. 

[Paz]

This is really useful thanks for posting. I mostly get inspiration from the cambridge double star atlas for easy doubles. There are 12 doubles in Canis minor in that atlas which one would think is plenty, and I have never had a problem finding nice targets to that level, but this post illustrates how as you go a bit deeper the number of targets grows exponentially.

[Mr Spock]

34 minutes ago, Paz said:

There are 12 doubles in Canis minor in that atlas which one would think is plenty, and I have never had a problem finding nice targets to that level, but this post illustrates how as you go a bit deeper the number of targets grows exponentially.

With my LP and 4" I can only pick up 7 of those  This is why I'm using larger apertures now. With the 12" and LP that probably increases to over 300 and without LP, who knows 

[IB20]

This is brilliant, love both the colour coding and the database documenting. Do you do similar fit the 12”? Forgive my laziness but what’s the theoretical separation for the light cannon?

[Mr Spock]

4 minutes ago, IB20 said:

what’s the theoretical separation for the light cannon?

0.38". On a night of good seeing I've managed 0.5" (Cou1923) on 25/08/22. On other good nights 0.6" is routine but needs at least x300

My maps for the 4" are 20° x 14° so don't go as faint. I only mark doubles down to 10.0 secondary mag. The 12" maps are 10° x 7° and marked down to 12.5 secondary mag. Both use the same colour coding as I can remember it easily - that's why there's an odd change at 1.14" - the theoretical separation of the 4". Generally anything orange is easy in the 4" with red being tight; for the 12" red is easy with purple being tight.

[Mircea]

Michael

Thank you very much for sharing this map of double stars in CMi ! That's wonderful work !

 

Checking my logbook I found CMi is terra incognita to me.

I know there only STF 1126. I saw the Airy discs of it as touching and forming the shape of an ''8''  on March 10, 2012 with my 125mm F/6.9 Dobsonian.

Latter I split many times STF 1126 with my 200mm F/6.16 Dobsonian but I recorded only once the C companion of 11.99 m with separation of 43'' on February 18, 2019.

(I don't know why I booked the separation of C as 41'' in my notes ... )

 

On Antique Telescope Society's forum it was an interesting discussion regarding the companion of Procyon.

It was mentioned BRD 2, a triple star located between Procyon and STF 1126 which was discovered by newyorker amateur Jacob Campbell in 1867 as reported in Scientific American. BRD 2AB is a subarc of 0.8''.

I see BRD 2 on your map. I will start using your map by giving a try to this triple star using my 250mm Dobsonian.

However, StelleDoppie / WDS mention the year of discovery as 1867 but the designation BRD don't mention Campbell.

The BRD designation is not included here:

double star designation (vaporia.com)

It seem BRD refer to an astronomer Bird. Do you know maybe more about designation BRD and astronomer/double star discoverer Bird, please ?

 

Clear sky, Mircea

 

 

 

[Mr Spock]

From WDS:

WDS  07h40m 59.56s +05°13'21.9"  D*WDS BRD 2 m1: 9.220  m2: 9.530    AB    sep:   0.9     pa:186 date:2005.00 sp: 1 A5  desc: BD+5.01741 WDS  07h40m 59.56s +05°13'21.9"  D*WDS BRD 2 m1: 8.610  m2:14.130   AB,C sep: 37.1     pa:334 date:2000.00 sp: 1 A5 desc: I know nothing about F Bird. Even a Google search shows nothing. In my LP skies 14.13 is beyond my 12". I generally only mark anything above 12.5 on the map. Yes, it really is that bad!

[DaveNicko]

I got a bit too obsessed very briefly looking for F Bird. He (I am making an assumption here) is referenced by the astronomer Sherburn Burnham in the following correspondence in Astronomical Register: https://articles.adsabs.harvard.edu/pdf/1872AReg...10..292B

And has submitted correspondence in his own right: https://articles.adsabs.harvard.edu/pdf/1867AReg....5..209J (see p7 of the PDF)

He was evidently from Birmingham, UK.

Dave

[wookie1965]

On 04/03/2023 at 13:32, Mr Spock said:

I keep everything in Excel. Here's an example of a session from last year:

Region	γ Cyg region
Date	from 20:30 27/09/2022 to 01:30 28/09/22
Scope	Stella Lyra 12" Newt
Eyepieces	42mm LVW, x40, LVW 22mm x69, LVW 17mm x89, LVW 13mm x117, LVW 8mm x190, LVW 5mm x304
Conditions	very good seeing and very good transparency - mag 4.8 in the direction of Cygnus
β 665	A faint and slightly uneven pair near γ Cyg; tight at x190
MLB 21	Too faint, sec not seen - should have been though at mag 12.0
D 22	An easy but uneven pair at x190
TOR 25	Very faint secondary, seems fainter than the published mag
MLB 22	A faint uneven pair x190
OΣΣ 206	A very wide pair x117
SEI 1117	Wide pair in the same field as OΣΣ 206 with a fainter star inbetween
SEI 1115	Wide pair at x190; in the same field as J 129 which was also resolved
TDT 2232	A tight, faint pair at x304
TDT 2233	In the same x304 field as TDT 2232; not as tight but a fainter secondary
Σ 2668	A bright uneven pair in the middle of a group of other doubles - the next five below
SEI 1091	Very wide, uneven pair at x69
SEI 1090	Very wide, uneven pair at x69
SEI 1094	Wide and very easy at x190
SEI 1097	Another wide pair at x190
TDS 1061	Tightest of the group, but resolved at x190
β 661	A very bright orange primary with a very faint secondary, x190
h 2951	A wide uneven pair at x190
Cou 2537	Tight! 0.8" resolved at x304 in moments of steady seeing
Σ 2663	A lovely even pair; looked nice at x117
HDS 90	Faint secondary - mag 12.6, about half the separation of Σ 2663 and in the same field at x117
SEI 1051	Wide uneven pair at x69
SEI 1070	Wide uneven pair at x69
COU 2536	Strangely difficult. Split at x190 in moments of steady seeing
SEI 1078	Another one of these wide, uneven blue pairs that seen to litter this region. X69

Wow can I ask where you get your information from I have never seen 3/4 of those doubles.

[Mr Spock]

35 minutes ago, wookie1965 said:

Wow can I ask where you get your information from I have never seen 3/4 of those doubles.

Washington Double Star catalogue in Cartes du Ciel.

[wookie1965]

1 hour ago, Mr Spock said:

Washington Double Star catalogue in Cartes du Ciel.

Thank you I have downloaded that but I could not get it to work no idea why.

[Mr Spock]

You have to install it to the correct place then enable it in the settings. 

[MalcolmM]

On 04/03/2023 at 12:12, Mr Spock said:

Here's my field map ready to go.

As usual, it has my 4" scope colour coding for separation. Yellow 30.0" and over, green 10.00" to 29.99", orange 3.00" to 9.99", red 1.14" to 2.99" and purple below 1.14"

What a brilliant idea! Thanks for sharing. I've been struggling how to visually show what doubles are within reach of 60mm/100mm scopes. 

Malcolm