2020-07-21, 07:22 PM
(This post was last modified: 2020-07-21, 07:26 PM by theskyhound.)
Hi,
You switched things up on me there. We were talking about deep sky objects when I said the objects had to be detectable to be displayed. But what you have posted are stars. Stars are handled differently. These are stars for an alignment, which we already talked about as a special case! So this particular list is not all that useful to pick apart.
But going with what you posted, the main reason people look at stars is to view a double-star pair. Most of your alignment stars are doubles. When viewing a double star pair, steady seeing is essential. The seeing is strongly affected by the altitude of the object. SkyTools looks at the pair and your optics on a case by case basis when it makes these determinations, but we can generalize. For excellent seeing you can go a lot closer to the horizon before everything is a blur and you are wasting your time. For average seeing, as you have selected, you need to stay away from the horizon. It's not good enough to just be able to see an object. As you note, we want a quality view. If you look at the quality for the stars you have selected, it is extremely poor at the time when they are filtered out. It is the quality that "Best Now" is looking at for the current time. Yes, you can technically see Arcturus, but given what you have told SkyTools about the seeing and other weather conditions it is going to be a big blurry blob near the horizon. So that is the equivalent of "don't bother."
I had anticipated screen captures of the deep sky list that you described that included the Veil nebula. From what you described it sounded like it should have been observable, but I suspect in fact that there was some reason that it was not. If, for instance, it is challenging in your telescope under your seeing, temperature, and humidity conditions, it may have to be high in the sky in order to be able to detect it. Without more information all I can do is speculate. But what I can tell you is that provided that you have correct information for your telescope, eyepieces, location, sky brightness, seeing, and weather conditions, then if an object is not listed there is a very good reason for it not to be. The Best Now does not list objects that are only at their best. It lists all objects that are "observable in a meaningful way" and then sorts the best objects to observe right now to the top.
You switched things up on me there. We were talking about deep sky objects when I said the objects had to be detectable to be displayed. But what you have posted are stars. Stars are handled differently. These are stars for an alignment, which we already talked about as a special case! So this particular list is not all that useful to pick apart.
But going with what you posted, the main reason people look at stars is to view a double-star pair. Most of your alignment stars are doubles. When viewing a double star pair, steady seeing is essential. The seeing is strongly affected by the altitude of the object. SkyTools looks at the pair and your optics on a case by case basis when it makes these determinations, but we can generalize. For excellent seeing you can go a lot closer to the horizon before everything is a blur and you are wasting your time. For average seeing, as you have selected, you need to stay away from the horizon. It's not good enough to just be able to see an object. As you note, we want a quality view. If you look at the quality for the stars you have selected, it is extremely poor at the time when they are filtered out. It is the quality that "Best Now" is looking at for the current time. Yes, you can technically see Arcturus, but given what you have told SkyTools about the seeing and other weather conditions it is going to be a big blurry blob near the horizon. So that is the equivalent of "don't bother."
I had anticipated screen captures of the deep sky list that you described that included the Veil nebula. From what you described it sounded like it should have been observable, but I suspect in fact that there was some reason that it was not. If, for instance, it is challenging in your telescope under your seeing, temperature, and humidity conditions, it may have to be high in the sky in order to be able to detect it. Without more information all I can do is speculate. But what I can tell you is that provided that you have correct information for your telescope, eyepieces, location, sky brightness, seeing, and weather conditions, then if an object is not listed there is a very good reason for it not to be. The Best Now does not list objects that are only at their best. It lists all objects that are "observable in a meaningful way" and then sorts the best objects to observe right now to the top.
Clear skies,
Greg
Head Dude at Skyhound
Greg
Head Dude at Skyhound