Double stars I discovered!

On May 22, 7:41*am, "Mike Dworetsky"
wrote:
wrote in message

...
On May 21, 6:31 pm, "Mike Dworetsky"





wrote:
"ukastronomy" wrote in message

...
On 21 May, 08:39, wrote:

On May 20, 2:38 pm, "Mike Dworetsky"

wrote:
wrote in message

...

I have been dilligently searching with my 8-inch Skywatcher Newt for
pairs of stars in the northern skies in last couple of years, that
have not previously been recorded in the Washington Double Star
catalogues. I happen to come upon a few pairs that I believe should
be
added to the catalog as potential true binaries. That is to say, I
believe the pairs are close enough in angular separation and display
siimilar stellar attributes to rank as genuine binaries, and not
merely line of sight optical doubles.

I checked my observation with the current WDS catalogue, listed
he
http://ad.usno.navy.mil/wds/wdstext.html

and they definitely aint listed there!! So these are genuine new
discoveries!!

I'm not sure where to send my observations, but I guess I should
post
them to the astronomy groups here first to see if you guys have
already beaten me to these binaries!?

I like to announce to the astronomy groups that I have identified 3
pairs in total that I plan on investigating further in coming years.
They a

FIRST PAIR (In Vulpecula):

RA 19h 52m 13.1s, Dec +27deg 27min 0.8arcsecs (Mag around 8.5)

RA 19h 52m 12.9s, Dec +27deg 26min 29.0arcsec (Mag
around 8.7)

The separation is approx 30" (30 arc-seconds as of May 17, 2009),
position is J2000.0 when I matched them to Stellarium software on my
PC

The next two pairs flank the star HP63952 in Ursa Major, to the
north
of the Handle of the Plough.

PAIR TO THE RIGHT OF HP63952:

RA 13h 06m 23.8s, Dec +62deg 03min 44.6arcsec (Mag around
9.2)

RA 13h 06m 22.3s, Dec +62deg 03min 43.2arcsec (mag of
about 9.9)

Separation is about 22" (22 arc-seconds)

PAIR TO THE LEFT OF HP63952:

RA 13h 06m 23.2s, Dec +62deg 01min 08.6arcsec (magnitude
about 8.9)

RA 13h 06m 24.7s, Dec +62deg 00min 53.4arcsec (mag about
9.8)

Separation of approx 25" (25 arc-seconds)

They are fairly wide, but the stars are reddish in colour, so my
guess
is they are red dwarfs and may be not too far away in distance,
making
them appear wider in separation...

Robert Grant Aitken, the famous observer of double stars, set a
general
criterion of likely physical pairing vs magnitude as log(rho) = 2..6 -
0.2 m
where rho is the separation in arcsec. If a pair fall within that
limit,
then it is probably a true physical pair (more data would be needed to
clinch the identification) while if it is outside the limit, the pair
is
probably optical (though with more data you might be able to prove the
opposite, such as spectral class, including luminosity classification,
proper motion and accurate radial velocity for example).

An example:

For mag 9.0, 2.6 -1.8 = 0.8 and 10^0.8 = 6.3 arcsec, so with your
pairs
falling far outside that range they are very unlikely to be physical
pairs
and are probably chance associations.

You will find Aitken's criterion discussed in

http://adsabs.harvard.edu/abs/1932MNRAS..92..596A

Aitken, R. G., MNRAS, 92, 596, 1932.

"What we know about double stars" (George Darwin Lecture)

From Simbad:

http://simbad.u-strasbg.fr/simbad/

Your first pair with separation around 31-32 arcsec is
BD+27 3542 (pm -1.40, -6.50 mas/yr) V = 8.69 (B-V = 0.76) and
HD 339063 (pm -0.50, -17.40 mas/yr) V = 8.69 (B-V = 0.53)

Errors quoted for components of pm are around 1-2 mas/yr, so this
rules
out
these stars being a common proper motion pair. Having the same
magnitude
but different colours also is not what would be expected of a physical
pair
at the same distance from us.

These are pretty small proper motions which also suggests these stars
are
not nearby red dwarves.

I don't have time to do all your pairs, and have to leave it to you..

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)- Hide quoted text -

- Show quoted text -

Like I said before, the pairs are close enough in separation to rank
as true double stars and any physical association is only suspected.
I'd just leave it at that for now. They are still pairs I discovered!
No???- Hide quoted text -

- Show quoted text -

Mike has given a good summary of the science and all that I would add
is that although you have discovered nothing of significance you have
had fun and have learnt something new.
---------------------------------------------------------------------------**-----

I have nothing at all against amateur astronomers enjoying looking at the
night sky. That's why it's there, isn't it? Just don't read more into the
observations than is warranted.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)- Hide quoted text -

- Show quoted text -

I totally agree. This business of 'hey i discovered this, and he
discovered that' is just pure fun. The night sky and its vast riches
in reality belong to no man...and the doubles do not even belong to
Struve or Herschel or Aitken. Any more than the Galilean moons belong
to Galileo LOL
--------------------------------------------------------------------------

Except, of course, that we still attach the names of the discoverers to the
Struve, Herschel, and Aitken double stars in the various lists, e.g.,
Struve's discoveries are indicated with a capital sigma and a number.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)- Hide quoted text -

- Show quoted text -

Of course!
Out of interest, how complete is SIMBAD database /query system? I dont
think it includes every star in every catalog. I ask because theres
one pair in draco (the dragon) where my notes were in pencil and not
100% readable, very obscure, going back a long time, but I have them
as:

RA 12 18 43.9, Dec +65 53 59.5 (of ~9.5th magnitude)
RA 12 18 43.0, Dec +65 53 53.3 (of mag ~10)

This isn't in the WDS catalogue and the separation is about 14" (14
arc-seconds), just outside the Aitken critera for binary stars.
Funny thing is theres no mention of either of these stars in
SIMBAD...when I tried the coordinate query?

wrote in message
...
On May 22, 7:41 am, "Mike Dworetsky"
wrote:
wrote in message

...
On May 21, 6:31 pm, "Mike Dworetsky"





wrote:
"ukastronomy" wrote in message

...
On 21 May, 08:39, wrote:

On May 20, 2:38 pm, "Mike Dworetsky"

wrote:
wrote in message

...

I have been dilligently searching with my 8-inch Skywatcher Newt
for
pairs of stars in the northern skies in last couple of years, that
have not previously been recorded in the Washington Double Star
catalogues. I happen to come upon a few pairs that I believe
should
be
added to the catalog as potential true binaries. That is to say, I
believe the pairs are close enough in angular separation and
display
siimilar stellar attributes to rank as genuine binaries, and not
merely line of sight optical doubles.

I checked my observation with the current WDS catalogue, listed
he
http://ad.usno.navy.mil/wds/wdstext.html

and they definitely aint listed there!! So these are genuine new
discoveries!!

I'm not sure where to send my observations, but I guess I should
post
them to the astronomy groups here first to see if you guys have
already beaten me to these binaries!?

I like to announce to the astronomy groups that I have identified
3
pairs in total that I plan on investigating further in coming
years.
They a

FIRST PAIR (In Vulpecula):

RA 19h 52m 13.1s, Dec +27deg 27min 0.8arcsecs (Mag around 8.5)

RA 19h 52m 12.9s, Dec +27deg 26min 29.0arcsec (Mag
around 8.7)

The separation is approx 30" (30 arc-seconds as of May 17, 2009),
position is J2000.0 when I matched them to Stellarium software on
my
PC

The next two pairs flank the star HP63952 in Ursa Major, to the
north
of the Handle of the Plough.

PAIR TO THE RIGHT OF HP63952:

RA 13h 06m 23.8s, Dec +62deg 03min 44.6arcsec (Mag around
9.2)

RA 13h 06m 22.3s, Dec +62deg 03min 43.2arcsec (mag of
about 9.9)

Separation is about 22" (22 arc-seconds)

PAIR TO THE LEFT OF HP63952:

RA 13h 06m 23.2s, Dec +62deg 01min 08.6arcsec (magnitude
about 8.9)

RA 13h 06m 24.7s, Dec +62deg 00min 53.4arcsec (mag about
9.8)

Separation of approx 25" (25 arc-seconds)

They are fairly wide, but the stars are reddish in colour, so my
guess
is they are red dwarfs and may be not too far away in distance,
making
them appear wider in separation...

Robert Grant Aitken, the famous observer of double stars, set a
general
criterion of likely physical pairing vs magnitude as log(rho) =
2.6 -
0.2 m
where rho is the separation in arcsec. If a pair fall within that
limit,
then it is probably a true physical pair (more data would be needed
to
clinch the identification) while if it is outside the limit, the
pair
is
probably optical (though with more data you might be able to prove
the
opposite, such as spectral class, including luminosity
classification,
proper motion and accurate radial velocity for example).

An example:

For mag 9.0, 2.6 -1.8 = 0.8 and 10^0.8 = 6.3 arcsec, so with your
pairs
falling far outside that range they are very unlikely to be physical
pairs
and are probably chance associations.

You will find Aitken's criterion discussed in

http://adsabs.harvard.edu/abs/1932MNRAS..92..596A

Aitken, R. G., MNRAS, 92, 596, 1932.

"What we know about double stars" (George Darwin Lecture)

From Simbad:

http://simbad.u-strasbg.fr/simbad/

Your first pair with separation around 31-32 arcsec is
BD+27 3542 (pm -1.40, -6.50 mas/yr) V = 8.69 (B-V = 0.76) and
HD 339063 (pm -0.50, -17.40 mas/yr) V = 8.69 (B-V = 0.53)

Errors quoted for components of pm are around 1-2 mas/yr, so this
rules
out
these stars being a common proper motion pair. Having the same
magnitude
but different colours also is not what would be expected of a
physical
pair
at the same distance from us.

These are pretty small proper motions which also suggests these
stars
are
not nearby red dwarves.

I don't have time to do all your pairs, and have to leave it to you.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)- Hide quoted text -

- Show quoted text -

Like I said before, the pairs are close enough in separation to rank
as true double stars and any physical association is only suspected.
I'd just leave it at that for now. They are still pairs I discovered!
No???- Hide quoted text -

- Show quoted text -

Mike has given a good summary of the science and all that I would add
is that although you have discovered nothing of significance you have
had fun and have learnt something new.
---------------------------------------------------------------------------**-----

I have nothing at all against amateur astronomers enjoying looking at
the
night sky. That's why it's there, isn't it? Just don't read more into
the
observations than is warranted.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)- Hide quoted text -

- Show quoted text -

I totally agree. This business of 'hey i discovered this, and he
discovered that' is just pure fun. The night sky and its vast riches
in reality belong to no man...and the doubles do not even belong to
Struve or Herschel or Aitken. Any more than the Galilean moons belong
to Galileo LOL
--------------------------------------------------------------------------

Except, of course, that we still attach the names of the discoverers to
the
Struve, Herschel, and Aitken double stars in the various lists, e.g.,
Struve's discoveries are indicated with a capital sigma and a number.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)- Hide quoted text -

- Show quoted text -

Of course!
Out of interest, how complete is SIMBAD database /query system? I dont
think it includes every star in every catalog. I ask because theres
one pair in draco (the dragon) where my notes were in pencil and not
100% readable, very obscure, going back a long time, but I have them
as:

RA 12 18 43.9, Dec +65 53 59.5 (of ~9.5th magnitude)
RA 12 18 43.0, Dec +65 53 53.3 (of mag ~10)

This isn't in the WDS catalogue and the separation is about 14" (14
arc-seconds), just outside the Aitken critera for binary stars.
Funny thing is theres no mention of either of these stars in
SIMBAD...when I tried the coordinate query?

-----------------------------------------------------------------------------------------

MD says:

I'm not sure--there may be somewhere an explanation of how stars get into
Simbad, and I don't think being only in the Guide Star Catalogue is enough,
so this may be the only source where there are any details at all.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

On May 22, 6:25*pm, "Mike Dworetsky"
wrote:
wrote in message

...
On May 22, 7:41 am, "Mike Dworetsky"





wrote:
wrote in message

....
On May 21, 6:31 pm, "Mike Dworetsky"

wrote:
"ukastronomy" wrote in message

....
On 21 May, 08:39, wrote:

On May 20, 2:38 pm, "Mike Dworetsky"

wrote:
wrote in message

...

I have been dilligently searching with my 8-inch Skywatcher Newt
for
pairs of stars in the northern skies in last couple of years, that
have not previously been recorded in the Washington Double Star
catalogues. I happen to come upon a few pairs that I believe
should
be
added to the catalog as potential true binaries. That is to say, I
believe the pairs are close enough in angular separation and
display
siimilar stellar attributes to rank as genuine binaries, and not
merely line of sight optical doubles.

I checked my observation with the current WDS catalogue, listed
he
http://ad.usno.navy.mil/wds/wdstext.html

and they definitely aint listed there!! So these are genuine new
discoveries!!

I'm not sure where to send my observations, but I guess I should
post
them to the astronomy groups here first to see if you guys have
already beaten me to these binaries!?

I like to announce to the astronomy groups that I have identified
3
pairs in total that I plan on investigating further in coming
years.
They a

FIRST PAIR (In Vulpecula):

RA 19h 52m 13.1s, Dec +27deg 27min 0.8arcsecs (Mag around 8.5)

RA 19h 52m 12.9s, Dec +27deg 26min 29.0arcsec (Mag
around 8.7)

The separation is approx 30" (30 arc-seconds as of May 17, 2009),
position is J2000.0 when I matched them to Stellarium software on
my
PC

The next two pairs flank the star HP63952 in Ursa Major, to the
north
of the Handle of the Plough.

PAIR TO THE RIGHT OF HP63952:

RA 13h 06m 23.8s, Dec +62deg 03min 44.6arcsec (Mag around
9.2)

RA 13h 06m 22.3s, Dec +62deg 03min 43.2arcsec (mag of
about 9.9)

Separation is about 22" (22 arc-seconds)

PAIR TO THE LEFT OF HP63952:

RA 13h 06m 23.2s, Dec +62deg 01min 08.6arcsec (magnitude
about 8.9)

RA 13h 06m 24.7s, Dec +62deg 00min 53.4arcsec (mag about
9.8)

Separation of approx 25" (25 arc-seconds)

They are fairly wide, but the stars are reddish in colour, so my
guess
is they are red dwarfs and may be not too far away in distance,
making
them appear wider in separation...

Robert Grant Aitken, the famous observer of double stars, set a
general
criterion of likely physical pairing vs magnitude as log(rho) =
2.6 -
0.2 m
where rho is the separation in arcsec. If a pair fall within that
limit,
then it is probably a true physical pair (more data would be needed
to
clinch the identification) while if it is outside the limit, the
pair
is
probably optical (though with more data you might be able to prove
the
opposite, such as spectral class, including luminosity
classification,
proper motion and accurate radial velocity for example).

An example:

For mag 9.0, 2.6 -1.8 = 0.8 and 10^0.8 = 6.3 arcsec, so with your
pairs
falling far outside that range they are very unlikely to be physical
pairs
and are probably chance associations.

You will find Aitken's criterion discussed in

http://adsabs.harvard.edu/abs/1932MNRAS..92..596A

Aitken, R. G., MNRAS, 92, 596, 1932.

"What we know about double stars" (George Darwin Lecture)

From Simbad:

http://simbad.u-strasbg.fr/simbad/

Your first pair with separation around 31-32 arcsec is
BD+27 3542 (pm -1.40, -6.50 mas/yr) V = 8.69 (B-V = 0.76) and
HD 339063 (pm -0.50, -17.40 mas/yr) V = 8.69 (B-V = 0.53)

Errors quoted for components of pm are around 1-2 mas/yr, so this
rules
out
these stars being a common proper motion pair. Having the same
magnitude
but different colours also is not what would be expected of a
physical
pair
at the same distance from us.

These are pretty small proper motions which also suggests these
stars
are
not nearby red dwarves.

I don't have time to do all your pairs, and have to leave it to you.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)- Hide quoted text -

- Show quoted text -

Like I said before, the pairs are close enough in separation to rank
as true double stars and any physical association is only suspected..
I'd just leave it at that for now. They are still pairs I discovered!
No???- Hide quoted text -

- Show quoted text -

Mike has given a good summary of the science and all that I would add
is that although you have discovered nothing of significance you have
had fun and have learnt something new.
---------------------------------------------------------------------------***-----

I have nothing at all against amateur astronomers enjoying looking at
the
night sky. That's why it's there, isn't it? Just don't read more into
the
observations than is warranted.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)- Hide quoted text -

- Show quoted text -

I totally agree. This business of 'hey i discovered this, and he
discovered that' is just pure fun. The night sky and its vast riches
in reality belong to no man...and the doubles do not even belong to
Struve or Herschel or Aitken. Any more than the Galilean moons belong
to Galileo LOL
--------------------------------------------------------------------------

Except, of course, that we still attach the names of the discoverers to
the
Struve, Herschel, and Aitken double stars in the various lists, e.g.,
Struve's discoveries are indicated with a capital sigma and a number.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)- Hide quoted text -

- Show quoted text -

Of course!
Out of interest, how complete is SIMBAD database /query system? I dont
think it includes every star in every catalog. I ask because theres
one pair in draco (the dragon) where my notes were in pencil and not
100% readable, very obscure, going back a long time, but I have them
as:

RA 12 18 43.9, Dec +65 53 59.5 (of ~9.5th magnitude)
RA 12 18 43.0, Dec +65 53 53.3 (of mag ~10)

This isn't in the WDS catalogue and the separation is about 14" (14
arc-seconds), just outside the Aitken critera for binary stars.
Funny thing is theres no mention of either of these stars in
SIMBAD...when I tried the coordinate query?

---------------------------------------------------------------------------*--------------

MD says:

I'm not sure--there may be somewhere an explanation of how stars get into
Simbad, and I don't think being only in the Guide Star Catalogue is enough,
so this may be the only source where there are any details at all.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)- Hide quoted text -

- Show quoted text -

This is a major problem when things in the sky are not in SIMBAD. How
to prove these stars really exist?

I published my discoveries he
http://uk.geocities.com/aa_spaceagent/Double-Stars.html

But I am still not happy with the pairs at:

Primary is in SIMBAD: BD+48 2520 -- Star
ICRS coord. (ep=2000) : 17 27 56.523 +47 54 30.72
Proper motions mas/yr [error ellipse]: -90.5 37.0 [5.1 5.0 90]
Spectral type: G0 D
V 9.1

The secondary is of V 9.75 but is not listed in SIMBAD.
The Separation A-B is just 10.5 arc-seconds making this a reasonably
close pair to be a genuine binary more than likely!

And the third pair Hercules I am going to have to take another look,
as I didn't really bother with it after one glimpse:

There is no inclusion of this pair in Washington Double Star catalogue
and there is no result in SIMBAD either. The only match I could find
was in Stellarium:
J2000.0: RA = 18 04 40.3, Dec = +23 57 52.3
Mags of ~9.5 and ~10.0, separation ~5 arcseconds apart! Both appeared
slightly reddish. True binary!
The location is actually very close to the star HP 88528

On 23 May, 05:58, wrote:

But I am still not happy with the pairs at:

Primary is in SIMBAD: BD+48 2520 -- Star
ICRS coord. (ep=2000) : 17 27 56.523 +47 54 30.72
Proper motions mas/yr [error ellipse]: -90.5 37.0 [5.1 5.0 90]
Spectral type: G0 D
V 9.1

The secondary is of V 9.75 but is not listed in SIMBAD.
The Separation A-B is just 10.5 arc-seconds making this a reasonably
close pair to be a genuine binary more than likely!

If I input the position you quote into the Digitized Sky Survey (or
indeed into Vizier) there is indeed a star at the position claimed (it
is TYC 3513-925-1) but there is not - repeat not - another 9.75
magnitude star within 10.5 arc seconds of TYC 3513-925-1.

TYC 3513-925-1 has a large proper motion - look at the PPMX listing.



And the third pair Hercules I am going to have to take another look,
as I didn't really bother with it after one glimpse:

There is no inclusion of this pair in Washington Double Star catalogue
and there is no result in SIMBAD either. The only match I could find
was in Stellarium:
J2000.0: RA = 18 04 40.3, Dec = +23 57 52.3
Mags of ~9.5 and ~10.0, separation ~5 arcseconds apart! Both appeared
slightly reddish. True binary!
The location is actually very close to the star HP 88528- Hide quoted text -

- Show quoted text -

The well known pair STF2274 is close by but assuming your positions
are accurate then again I cannot find any photographic evidence of the
two close stars you have identified.

Have you actually seen them with your own eyes or are you relying on
planetarium software?

On May 23, 7:56*am, ukastronomy
wrote:
On 23 May, 05:58, wrote:



But I am still not happy with the pairs at:

Primary is in SIMBAD: BD+48 2520 -- Star
ICRS coord. (ep=2000) : 17 27 56.523 +47 54 30.72
Proper motions mas/yr [error ellipse]: -90.5 37.0 [5.1 5.0 90]
Spectral type: G0 D
V 9.1

The secondary is of V 9.75 but is not listed in SIMBAD.
The Separation A-B is just 10.5 arc-seconds making this a reasonably
close pair to be a genuine binary more than likely!

If I input the position you quote into the Digitized Sky Survey (or
indeed into Vizier) there is indeed a star at the position claimed (it
is TYC 3513-925-1) but there is not - repeat not - another 9.75
magnitude star within 10.5 arc seconds of TYC 3513-925-1.

TYC 3513-925-1 has a large proper motion - look at the PPMX listing.



And the third pair Hercules I am going to have to take another look,
as I didn't really bother with it after one glimpse:

There is no inclusion of this pair in Washington Double Star catalogue
and there is no result in SIMBAD either. The only match I could find
was in Stellarium:
J2000.0: RA = 18 04 40.3, Dec = +23 57 52.3
Mags of ~9.5 and ~10.0, separation ~5 arcseconds apart! Both appeared
slightly reddish. True binary!
The location is actually very close to the star HP 88528- Hide quoted text -

- Show quoted text -

The well known pair STF2274 is close by but assuming your positions
are accurate then again I cannot find any photographic evidence of the
two close stars you have identified.

Have you actually seen them with your own eyes or are you relying on
planetarium software?

Thank you for checking. My telescope is problematic for seeing
overhead (zenith). This is actually one I glimpse last autumn when the
head of Draco was much off zenith. I did make a diagram of it, but now
its impossible since my tripod stops the tube on 200 EQ mount of my
skywatcher. Impossible for me this time of year.
If your telescope allows, would you mind having a look?

The Hercles pair I saw again last night: J2000 18 24 59.6, +16 41
55.5. The secondary is definitely there! I saw it about 23 arcseconds
away at mag 10 to 11. Can you check it in your Digitized Sky Survey
please?

On 23 May, 09:53, wrote:
On May 23, 7:56*am, ukastronomy
wrote:





On 23 May, 05:58, wrote:

But I am still not happy with the pairs at:

Primary is in SIMBAD: BD+48 2520 -- Star
ICRS coord. (ep=2000) : 17 27 56.523 +47 54 30.72
Proper motions mas/yr [error ellipse]: -90.5 37.0 [5.1 5.0 90]
Spectral type: G0 D
V 9.1

The secondary is of V 9.75 but is not listed in SIMBAD.
The Separation A-B is just 10.5 arc-seconds making this a reasonably
close pair to be a genuine binary more than likely!

If I input the position you quote into the Digitized Sky Survey (or
indeed into Vizier) there is indeed a star at the position claimed (it
is TYC 3513-925-1) but there is not - repeat not - another 9.75
magnitude star within 10.5 arc seconds of TYC 3513-925-1.

TYC 3513-925-1 has a large proper motion - look at the PPMX listing.

And the third pair Hercules I am going to have to take another look,
as I didn't really bother with it after one glimpse:

There is no inclusion of this pair in Washington Double Star catalogue
and there is no result in SIMBAD either. The only match I could find
was in Stellarium:
J2000.0: RA = 18 04 40.3, Dec = +23 57 52.3
Mags of ~9.5 and ~10.0, separation ~5 arcseconds apart! Both appeared
slightly reddish. True binary!
The location is actually very close to the star HP 88528- Hide quoted text -

- Show quoted text -

The well known pair STF2274 is close by but assuming your positions
are accurate then again I cannot find any photographic evidence of the
two close stars you have identified.

Have you actually seen them with your own eyes or are you relying on
planetarium software?

Thank you for checking. My telescope is problematic for seeing
overhead (zenith). This is actually one I glimpse last autumn when the
head of Draco was much off zenith. I did make a diagram of it, but now
its impossible since my tripod stops the tube on 200 EQ mount of my
skywatcher. Impossible for me this time of year.
If your telescope allows, would you mind having a look?

The Hercles pair I saw again last night: J2000 18 24 59.6, +16 41
55.5. The secondary is definitely there! I saw it about 23 arcseconds
away at mag 10 to 11. Can you check it in your Digitized Sky Survey
please?- Hide quoted text -

- Show quoted text -

There are 2 Tycho stars (8.2 and 10) that are about 17 or 18 arc secs
apart but they have very different proper motions so are not linked
physically.

My reply didn't propagate--I'm repeating it below, in case you didn't see
it.

wrote in message
...
On May 23, 7:56 am, ukastronomy
wrote:
On 23 May, 05:58, wrote:



But I am still not happy with the pairs at:

Primary is in SIMBAD: BD+48 2520 -- Star
ICRS coord. (ep=2000) : 17 27 56.523 +47 54 30.72
Proper motions mas/yr [error ellipse]: -90.5 37.0 [5.1 5.0 90]
Spectral type: G0 D
V 9.1

The secondary is of V 9.75 but is not listed in SIMBAD.
The Separation A-B is just 10.5 arc-seconds making this a reasonably
close pair to be a genuine binary more than likely!

If I input the position you quote into the Digitized Sky Survey (or
indeed into Vizier) there is indeed a star at the position claimed (it
is TYC 3513-925-1) but there is not - repeat not - another 9.75
magnitude star within 10.5 arc seconds of TYC 3513-925-1.

TYC 3513-925-1 has a large proper motion - look at the PPMX listing.



And the third pair Hercules I am going to have to take another look,
as I didn't really bother with it after one glimpse:

There is no inclusion of this pair in Washington Double Star catalogue
and there is no result in SIMBAD either. The only match I could find
was in Stellarium:
J2000.0: RA = 18 04 40.3, Dec = +23 57 52.3
Mags of ~9.5 and ~10.0, separation ~5 arcseconds apart! Both appeared
slightly reddish. True binary!
The location is actually very close to the star HP 88528- Hide quoted
text -

- Show quoted text -

The well known pair STF2274 is close by but assuming your positions
are accurate then again I cannot find any photographic evidence of the
two close stars you have identified.

Have you actually seen them with your own eyes or are you relying on
planetarium software?

Thank you for checking. My telescope is problematic for seeing
overhead (zenith). This is actually one I glimpse last autumn when the
head of Draco was much off zenith. I did make a diagram of it, but now
its impossible since my tripod stops the tube on 200 EQ mount of my
skywatcher. Impossible for me this time of year.
If your telescope allows, would you mind having a look?

The Hercles pair I saw again last night: J2000 18 24 59.6, +16 41
55.5. The secondary is definitely there! I saw it about 23 arcseconds
away at mag 10 to 11. Can you check it in your Digitized Sky Survey
please?

---------------------------------------------------------------------------------------

MD advises:

Take a look at the Aladin Previewer in Simbad. This will give you a POSS II
Sky Survey image (jpg) or 2MASS (fits: needs a fits viewer installed) of a
12.9x12.9 arcmin area around the object. It's a fun tool, try it. You can
even ask for the images of the original POSS I.

Your star is the brightest in the field. Within about 30 arcsec there are 4
other objects a couple of magnitudes fainter of similar brightness to one
another. Your companion is the closest and brightest only by a small
margin, and looks much less red than the bright star. It doesn't look like
anything more than a random grouping of field stars. I see at least 4 or 5
other similar size groups of 4-5 stars of about the same brightness in the
image. You can ask Aladin to give you a colour view (composite of POSS II F
and J plates), and while your primary looks red (well, orange), the
surrounding stars are definitely yellower or white.

There is a neat close asterism of what looks like 5 white stars (white in
this combination = roughly class late A or F?? I'm guessing) maybe 14th mag
(?? uncertain), about 3 min away at about 1 o'clock. I'd love to think that
it is physical, but at this sort of level of brightness such things show up
a lot and are usually random alignments. (One would need a 5-m telescope to
prove otherwise). There is at least one fairly blue 10th mag star in the
field 10 or 11 arcmin away NW.

My best take on this: the secondary you found does not seem to be a physical
companion and is just another field star among many.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

In article ,
"Mike Dworetsky" wrote:

snip

I'm not sure--there may be somewhere an explanation of how stars get into
Simbad, and I don't think being only in the Guide Star Catalogue is enough,
so this may be the only source where there are any details at all.

Simbad's sources are listed at

http://cdsarc.u-strasbg.fr/cats/cats.html.

--
Odysseus

"Odysseus" wrote in message
news
In article ,
"Mike Dworetsky" wrote:

snip

I'm not sure--there may be somewhere an explanation of how stars get into
Simbad, and I don't think being only in the Guide Star Catalogue is
enough,
so this may be the only source where there are any details at all.

Simbad's sources are listed at

http://cdsarc.u-strasbg.fr/cats/cats.html.

--
Odysseus

Simbad has around 2.5 million objects (or is it more now?), the Guide Star
Catalogue about 15 million, so if an object is in the GSC it is far from
obvious that it will be in the Simbad list.

There are various software apps which interrogate the entire GSC, however.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)