Naked eye star splitting

Last night while observing the moon my youngest daughter who is 13 came out
to have a peek, she asked if there was anything to look at other than the
moon. I asked her if she would like to see a double star in the big dippers
handle. She asked what a double star was so I explained as I pointed the dob
in the direction of Mizar/Alcor double in Ursa Major. She asked me where I
was looking and I told her that I was pointing towards the second star in
the big dippers handle and she said "Oh you mean those two stars that are
side by side, is that what we are going to look at?" I aligned the bulls eye
in the Telrad up with Mizar and had her look through it to see if that was
indeed what she meant, and she said "yea those two in the center of the
little red circle" I was amazed, I see only one star there with my naked
eyes, she sees two and told me one was brighter than the other to boot! The
Moon was up and so because I could barely see Megrez I guessed the sky to be
about mag 3.5, my question is, is it normal for young children to be able to
see this double star with naked eyes? Now comes the kicker, I decided to
look at the M27, after I found it I had her look at it. She looked at it
through the telescope and then went to the Telrad, looked at the position it
was in the sky and told me she could see a fuzzy blob there without the
telescope! She swears this to be so, we were pretty well dark adapted and
hadn't looked at the moon in about 20 minutes. Is this possible given the
mag 3.5 sky? (as observed by me). I sure wish my eyes were that good!

Tom Wales

Tom Wales wrote:
my question is, is it normal for young children to be able to
see this double star with naked eyes?

Mizar/Alcor? Most certainly. The two stars are 12 arcminutes
apart--about 40 percent of the width of the Full Moon. Alcor, the
dimmer star, is about magnitude 4.0, so it's likely the reason you didn't
see it isn't the separation, but the dimness (in your bright sky). To
you, it was a magnitude 3.5 sky, maybe, but to her, it was at least as
good as magnitude 4.0.

Now comes the kicker, I decided to look at the M27, after I found it
I had her look at it. She looked at it through the telescope and then
went to the Telrad, looked at the position it was in the sky and told
me she could see a fuzzy blob there without the telescope! She swears
this to be so, we were pretty well dark adapted and hadn't looked at
the moon in about 20 minutes. Is this possible given the mag 3.5 sky?
(as observed by me). I sure wish my eyes were that good!

Gee...well, it seems pretty unlikely to me. I have M27 as magnitude 7.4,
which is considerably tougher than Alcor, especially as M27 is an extended
object (not a point source), and it's not a pristine sky, even if you
haven't looked directly at the Moon for 20 minutes. My guess is that she
saw a star at the limit of her visibility and confused it for M27, but
these kids--you never know.

Brian Tung
The Astronomy Corner at http://astro.isi.edu/
Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/
The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/
My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.txt

Tom Wales wrote:
my question is, is it normal for young children to be able to
see this double star with naked eyes?

Mizar/Alcor? Most certainly. The two stars are 12 arcminutes
apart--about 40 percent of the width of the Full Moon. Alcor, the
dimmer star, is about magnitude 4.0, so it's likely the reason you didn't
see it isn't the separation, but the dimness (in your bright sky). To
you, it was a magnitude 3.5 sky, maybe, but to her, it was at least as
good as magnitude 4.0.

Now comes the kicker, I decided to look at the M27, after I found it
I had her look at it. She looked at it through the telescope and then
went to the Telrad, looked at the position it was in the sky and told
me she could see a fuzzy blob there without the telescope! She swears
this to be so, we were pretty well dark adapted and hadn't looked at
the moon in about 20 minutes. Is this possible given the mag 3.5 sky?
(as observed by me). I sure wish my eyes were that good!

Gee...well, it seems pretty unlikely to me. I have M27 as magnitude 7.4,
which is considerably tougher than Alcor, especially as M27 is an extended
object (not a point source), and it's not a pristine sky, even if you
haven't looked directly at the Moon for 20 minutes. My guess is that she
saw a star at the limit of her visibility and confused it for M27, but
these kids--you never know.

Brian Tung
The Astronomy Corner at http://astro.isi.edu/
Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/
The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/
My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.txt

On Tue, 29 Jun 2004 17:14:13 GMT, "Tom Wales"
wrote:

Last night while observing the moon my youngest daughter who is 13 came out
to have a peek, she asked if there was anything to look at other than the
moon. I asked her if she would like to see a double star in the big dippers
handle. She asked what a double star was so I explained as I pointed the dob
in the direction of Mizar/Alcor double in Ursa Major. She asked me where I
was looking and I told her that I was pointing towards the second star in
the big dippers handle and she said "Oh you mean those two stars that are
side by side, is that what we are going to look at?" I aligned the bulls eye
in the Telrad up with Mizar and had her look through it to see if that was
indeed what she meant, and she said "yea those two in the center of the
little red circle" I was amazed, I see only one star there with my naked
eyes, she sees two and told me one was brighter than the other to boot! The
Moon was up and so because I could barely see Megrez I guessed the sky to be
about mag 3.5, my question is, is it normal for young children to be able to
see this double star with naked eyes? Now comes the kicker, I decided to
look at the M27, after I found it I had her look at it. She looked at it
through the telescope and then went to the Telrad, looked at the position it
was in the sky and told me she could see a fuzzy blob there without the
telescope! She swears this to be so, we were pretty well dark adapted and
hadn't looked at the moon in about 20 minutes. Is this possible given the
mag 3.5 sky? (as observed by me). I sure wish my eyes were that good!

Tom Wales

Tom-

You need to get your eyes checked. Although it is claimed that some ancient
cultures used Mizar/Alcor as a test of visual acuity, that is hard to believe.
Anyone with something approaching normal vision, at any age, should be able to
split them, and detect the nearly two magnitude difference. Most people I show
them to fail to figure out what I'm talking about at first because Alcor and
Mizar are so far apart- they are expecting a double to be tighter.

That said, it is common for children to have very good eyesight. I can just
split eta Lyra under good conditions (I'm 46), but I've seen a number of kids do
it with apparent ease.

I'd doubt anybody's ability to see M27 naked eye even under perfect skies, let
alone mag 3.5. Nearby M71, a globular, might be slightly more believable, but
again, not under your skies.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

On Tue, 29 Jun 2004 17:14:13 GMT, "Tom Wales"
wrote:

Last night while observing the moon my youngest daughter who is 13 came out
to have a peek, she asked if there was anything to look at other than the
moon. I asked her if she would like to see a double star in the big dippers
handle. She asked what a double star was so I explained as I pointed the dob
in the direction of Mizar/Alcor double in Ursa Major. She asked me where I
was looking and I told her that I was pointing towards the second star in
the big dippers handle and she said "Oh you mean those two stars that are
side by side, is that what we are going to look at?" I aligned the bulls eye
in the Telrad up with Mizar and had her look through it to see if that was
indeed what she meant, and she said "yea those two in the center of the
little red circle" I was amazed, I see only one star there with my naked
eyes, she sees two and told me one was brighter than the other to boot! The
Moon was up and so because I could barely see Megrez I guessed the sky to be
about mag 3.5, my question is, is it normal for young children to be able to
see this double star with naked eyes? Now comes the kicker, I decided to
look at the M27, after I found it I had her look at it. She looked at it
through the telescope and then went to the Telrad, looked at the position it
was in the sky and told me she could see a fuzzy blob there without the
telescope! She swears this to be so, we were pretty well dark adapted and
hadn't looked at the moon in about 20 minutes. Is this possible given the
mag 3.5 sky? (as observed by me). I sure wish my eyes were that good!

Tom Wales

Tom-

You need to get your eyes checked. Although it is claimed that some ancient
cultures used Mizar/Alcor as a test of visual acuity, that is hard to believe.
Anyone with something approaching normal vision, at any age, should be able to
split them, and detect the nearly two magnitude difference. Most people I show
them to fail to figure out what I'm talking about at first because Alcor and
Mizar are so far apart- they are expecting a double to be tighter.

That said, it is common for children to have very good eyesight. I can just
split eta Lyra under good conditions (I'm 46), but I've seen a number of kids do
it with apparent ease.

I'd doubt anybody's ability to see M27 naked eye even under perfect skies, let
alone mag 3.5. Nearby M71, a globular, might be slightly more believable, but
again, not under your skies.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

"Brian Tung" wrote,
Mizar/Alcor? Most certainly. The two stars are 12 arcminutes
apart--about 40 percent of the width of the Full Moon.

Thanks Brian, I am fairly new to astronomy and don't yet have a total grasp
of the whole arcminute/arcsecond thing but I don't understand how these two
stars are considered 40% of the width of the full moon apart. In my
telescope they just barely split at 30X, in contrast the full moon is a
large 3/4 apature filling object at the same power. I'm not questioning your
knowledge or abilities or even that fact that what you say may be true. Am I
missing something?

Tom Wales

"Brian Tung" wrote,
Mizar/Alcor? Most certainly. The two stars are 12 arcminutes
apart--about 40 percent of the width of the Full Moon.

Thanks Brian, I am fairly new to astronomy and don't yet have a total grasp
of the whole arcminute/arcsecond thing but I don't understand how these two
stars are considered 40% of the width of the full moon apart. In my
telescope they just barely split at 30X, in contrast the full moon is a
large 3/4 apature filling object at the same power. I'm not questioning your
knowledge or abilities or even that fact that what you say may be true. Am I
missing something?

Tom Wales

Chris L Peterson wrote:
That said, it is common for children to have very good eyesight. I can just
split eta Lyra under good conditions (I'm 46), but I've seen a number of
kids do it with apparent ease.

This is not a nitpick. Honest!

I've now seen you write eta Lyra (or Lyrae) twice now. Are you sure you
mean eta Lyrae and not epsilon Lyrae? The separation of eta Lyrae is
about 28 arcseconds. If anyone, young or not, can do that with apparent
ease (or heck, even without apparent ease), that is simply amazing.

On the other hand, epsilon Lyrae has a separation of 208 arcseconds and
that, indeed, I can split without much difficulty. The trouble around
here in Santa Monica is finding a night on which the sky is dark enough
to see the stars in the first place, but if I can see them, I can split
them.

Brian Tung
The Astronomy Corner at http://astro.isi.edu/
Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/
The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/
My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.txt

Chris L Peterson wrote:
That said, it is common for children to have very good eyesight. I can just
split eta Lyra under good conditions (I'm 46), but I've seen a number of
kids do it with apparent ease.

This is not a nitpick. Honest!

I've now seen you write eta Lyra (or Lyrae) twice now. Are you sure you
mean eta Lyrae and not epsilon Lyrae? The separation of eta Lyrae is
about 28 arcseconds. If anyone, young or not, can do that with apparent
ease (or heck, even without apparent ease), that is simply amazing.

On the other hand, epsilon Lyrae has a separation of 208 arcseconds and
that, indeed, I can split without much difficulty. The trouble around
here in Santa Monica is finding a night on which the sky is dark enough
to see the stars in the first place, but if I can see them, I can split
them.

Brian Tung
The Astronomy Corner at http://astro.isi.edu/
Unofficial C5+ Home Page at http://astro.isi.edu/c5plus/
The PleiadAtlas Home Page at http://astro.isi.edu/pleiadatlas/
My Own Personal FAQ (SAA) at http://astro.isi.edu/reference/faq.txt

Tom Wales wrote:

Last night while observing the moon my youngest daughter who is 13 came out
to have a peek, she asked if there was anything to look at other than the
moon. I asked her if she would like to see a double star in the big dippers
handle. She asked what a double star was so I explained as I pointed the dob
in the direction of Mizar/Alcor double in Ursa Major. She asked me where I
was looking and I told her that I was pointing towards the second star in
the big dippers handle and she said "Oh you mean those two stars that are
side by side, is that what we are going to look at?" I aligned the bulls eye
in the Telrad up with Mizar and had her look through it to see if that was
indeed what she meant, and she said "yea those two in the center of the
little red circle" I was amazed, I see only one star there with my naked
eyes, she sees two and told me one was brighter than the other to boot! The
Moon was up and so because I could barely see Megrez I guessed the sky to be
about mag 3.5, my question is, is it normal for young children to be able to
see this double star with naked eyes? Now comes the kicker, I decided to
look at the M27, after I found it I had her look at it. She looked at it
through the telescope and then went to the Telrad, looked at the position it
was in the sky and told me she could see a fuzzy blob there without the
telescope! She swears this to be so, we were pretty well dark adapted and
hadn't looked at the moon in about 20 minutes. Is this possible given the
mag 3.5 sky? (as observed by me). I sure wish my eyes were that good!

Tom Wales

When I was a kid (grew up on an iowa farm without light pollution) I
could see that Epsilon Lyra was a double star.... can't do it now
without optics.

Have your daughter look at Epsilon Lyra.

I'd be interested in how many stars of the Pleiades she can see.