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STF 2048 with ruddy field star

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#1 rugby

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Posted 29 June 2020 - 07:13 PM

STF 2048 is pretty much garden variety when it comes to double stars. But Smythe recognized a reddish field star in the N-p quadrant of the field of view. I found it last night and concur there certainly some kind of colour here. I am not sensitive to red so all I saw was an abnormally warmish looking star.Its not the discovery that is important to me. Its the connection to the past.
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#2 chrysalis

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Posted 30 June 2020 - 09:31 AM

STF 2048 is pretty much garden variety when it comes to double stars. But Smythe recognized a reddish field star in the N-p quadrant of the field of view. I found it last night and concur there certainly some kind of colour here. I am not sensitive to red so all I saw was an abnormally warmish looking star.Its not the discovery that is important to me. Its the connection to the past.

The reddest star I find nearby using CdC is:

 

TYC5626-00772-1
Magnitude Tycho BT: 13.37
Magnitude Tycho VT: 11.43
Visual Magnitude: 11.26
Color Index:  1.65
Annual Proper Motion: -0.014 -0.008

J2000 RA:  16h27m29.02s   DE:-08°13'04.6"
Date  RA:  16h28m35.70s   DE:-08°15'45.1"

 

STF2048 (in Ophiuchus) position is:

 

J2000 RA:  16h28m48.90s   DE:-08°07'43.0"
Date  RA:  16h29m55.55s   DE:-08°10'21.2"


Edited by chrysalis, 30 June 2020 - 09:32 AM.

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#3 nerich

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Posted 30 June 2020 - 10:26 AM

The reddest star I find nearby using CdC is:

 

TYC5626-00772-1
Magnitude Tycho BT: 13.37
Magnitude Tycho VT: 11.43
Visual Magnitude: 11.26
Color Index:  1.65
Annual Proper Motion: -0.014 -0.008

J2000 RA:  16h27m29.02s   DE:-08°13'04.6"
Date  RA:  16h28m35.70s   DE:-08°15'45.1"

 

STF2048 (in Ophiuchus) position is:

 

J2000 RA:  16h28m48.90s   DE:-08°07'43.0"
Date  RA:  16h29m55.55s   DE:-08°10'21.2"


That's a red one indeed, Mark! But it's not quite in the right direction. My instinct is also that it's a little too dim for even the Admiral's sensitive eye to have seen a strong red color.

Rob Peeling, who did the updated and annotated Bedford Catalog for the Webb Deep Sky Society, says that the NP star is UCAC4 410-065894, with a Vmag of 12.7. That's possible, but again is getting really dim to see "a deep orange tinge" with 5.9 inches of aperture.

The first star that jumped out at me in Aladin was V2105 Ophiuchi, which is north west as the Admiral says. The trouble with this one is that it's a pretty good distance away, about two thirds of a degree. With the Admiral's 2590mm focal length, that would be a tough fit. He says in the first half of A Cycle of Celestial Objects that his eyepiece arsenal gives him powers as low as 22x (that's a 120mm f.l. eyepiece!) but I have no idea what the field stop or apparent field of those ancient things might have been. 

Here's an Aladin Screenshot. Rugby, is this the star you saw? 



V2105.jpg


 


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#4 chrysalis

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Posted 30 June 2020 - 12:38 PM

That's a red one indeed, Mark! But it's not quite in the right direction. My instinct is also that it's a little too dim for even the Admiral's sensitive eye to have seen a strong red color.

Rob Peeling, who did the updated and annotated Bedford Catalog for the Webb Deep Sky Society, says that the NP star is UCAC4 410-065894, with a Vmag of 12.7. That's possible, but again is getting really dim to see "a deep orange tinge" with 5.9 inches of aperture.

The first star that jumped out at me in Aladin was V2105 Ophiuchi, which is north west as the Admiral says. The trouble with this one is that it's a pretty good distance away, about two thirds of a degree. With the Admiral's 2590mm focal length, that would be a tough fit. He says in the first half of A Cycle of Celestial Objects that his eyepiece arsenal gives him powers as low as 22x (that's a 120mm f.l. eyepiece!) but I have no idea what the field stop or apparent field of those ancient things might have been. 

Here's an Aladin Screenshot. Rugby, is this the star you saw? 



attachicon.gifV2105.jpg


 

Yes, that looked too far to me too.

 

From CdC:

 

HR 6128 HD148349
Flamsteed Number:    
Bayer Letter:
Constellation:
Visual Magnitude:  5.23
Color Index:  1.72
Spectral Class:   M3-III            
Annual Proper Motion:  0.014 -0.155

J2000 RA:  16h27m43.50s   DE:-07°35'53.0"
Date  RA:  16h28m49.90s   DE:-07°38'33.1"

 

STF2048.JPG


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#5 nerich

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Posted 30 June 2020 - 01:19 PM

Yes, that looked too far to me too.

 

 

A bit of a mystery! 


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#6 rugby

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Posted 30 June 2020 - 05:01 PM

Thankyou for the wonderful detective work. I will make a drawing tonite and post later. Obviously something is amiss. My field of view conained STF 2048 and what I thought was the redder star.
It is unfortunate we dont have Smyth's eyepiece types.
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#7 rugby

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Posted 30 June 2020 - 10:34 PM

I have observed STF 2048 once more. V2105 is not the star. my target is roughly less than half the distance between v2105 and 2048. Yet from the photo it is hardly reddish and certainly not as orangey as V2105. Sorry all who have responded for what is turning out to be a goosechase.
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#8 nerich

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Posted 30 June 2020 - 11:18 PM

I have observed STF 2048 once more. V2105 is not the star. my target is roughly less than half the distance between v2105 and 2048. Yet from the photo it is hardly reddish and certainly not as orangey as V2105. Sorry all who have responded for what is turning out to be a goosechase.

I live for the goose chase. wink.gif


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#9 c2m2t

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Posted 01 July 2020 - 09:55 AM

Good Morning!

Can someone please repost the actual description that Admiral Smythe used to describe the field around STF 2048? I am not sure that he was describing a star that was contained, in what I suspect, was a fairly narrow field that included STF 2048. Given the brightness and intense colouration of V2105, I am wondering if this was a description that was based on a naked eye observation. 

 

Cheers, Chris.


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#10 nerich

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Posted 01 July 2020 - 10:13 AM

Here ya go, Chris:

A very delicate double star, close upon the Serpent-bearer's right thigh; it is 25° distant from α Herculis, on a line south-south-west towards β Scorpii, where it is also pointed out by a line through δ and ε, the two stars of the 3rd magnitude in the hand of Ophiuchus. A 7 ½, yellow; B 12, dusky; other stars in the field, particularly one of a deep orange tinge in the np. Nor ought I to omit mentioning that 6 Hevelii, or υ, precedes it to the southward by about a minute of time, since it is of the 5th magnitude, and forms a sort of pointer to the delicate pair, on an angle of 133°. This is a most difficult object, though Σ., its discoverer, gives the comes a 9th magnitude only, whereas, by comparison, I cannot rate it higher than I have...

Re-reading this now, it seems obvious that as he considered his mention of upsilon a bit out of the ordinary ("nor ought I to omit..."), including a star nearly twice as far away among the field objects doesn't seem likely. Indeed, I was suspicious that V2105 was his field star to begin with. 



#11 chrysalis

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Posted 01 July 2020 - 10:53 AM

Have we given up on this one at mag 11.3?

 

The reddest star I find nearby using CdC is:

 

TYC5626-00772-1
Magnitude Tycho BT: 13.37
Magnitude Tycho VT: 11.43
Visual Magnitude: 11.26
Color Index:  1.65
Annual Proper Motion: -0.014 -0.008

J2000 RA:  16h27m29.02s   DE:-08°13'04.6"
Date  RA:  16h28m35.70s   DE:-08°15'45.1"


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#12 c2m2t

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Posted 01 July 2020 - 10:57 AM

Hi Nick!

Thanks for the quick follow up! So...are you in agreement with the notion he was describing the much wider field??

 

Cheers, Chris.


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#13 nerich

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Posted 01 July 2020 - 11:53 AM

Have we given up on this one at mag 11.3?

 

The reddest star I find nearby using CdC is:

 

TYC5626-00772-1
Magnitude Tycho BT: 13.37
Magnitude Tycho VT: 11.43
Visual Magnitude: 11.26
Color Index:  1.65
Annual Proper Motion: -0.014 -0.008

J2000 RA:  16h27m29.02s   DE:-08°13'04.6"
Date  RA:  16h28m35.70s   DE:-08°15'45.1"

This one is roughly west/southwest, which is not quite the right direction. It would otherwise be a possibility!
 

 

Hi Nick!

Thanks for the quick follow up! So...are you in agreement with the notion he was describing the much wider field??

 

Cheers, Chris.

It's definitely possible! But I'm troubled by his description of Ups Oph. That he would include V2105 as part of his description of the "field," and then describe Upsilon as a follow-up, making a point to note its distance from the object at hand, seems suspect. 
 

I need to get a sense for what this grouping feels like in the eyepiece at various powers. I don't have a particularly good intuition for these things when it comes to looking at Aladin and trying to feel out the numbers! 

Also, not that it should make that much of a difference, but STF 2048 is a high proper motion system moving roughly south west (-54.5 and -69.8 mas/yr). Maybe those of you who are good with the numbers can wind the clock back about 180 years for us. 10 or 15 arc seconds in each direction, or something like that? 


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#14 rugby

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Posted 01 July 2020 - 02:40 PM

Is it possible we are over estimating Smythe's field of view. Would he have used moderate magnification and thus had a small field of view? If so, Upsilon would not be in the picture. i will finish by saying my colour vision is terrible and am going on gut feeling and personal acquaintance with the 2048 field.
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#15 nerich

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Posted 01 July 2020 - 07:28 PM

Is it possible we are over estimating Smythe's field of view. Would he have used moderate magnification and thus had a small field of view? If so, Upsilon would not be in the picture. i will finish by saying my colour vision is terrible and am going on gut feeling and personal acquaintance with the 2048 field.

Yeah, I'm inclined to think that his field description was smaller. I wish he had included magnifications! 

It's also possible that Smyth was describing an ordinary yellowish star which, for whatever reason, he saw as deeper orange. The Admiral had a pretty good eye, but color is subjective, as we all know. 




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