Kenny _____________ C-8, C-90, and C-14 in home built roll back roof backyard observatory
I don't believe in astrology. I am a Gemini and we're very skeptical.
Quote:If it makes you feel better, I have looked at the Ring with a 72" (yes really) for 10-15 secs, and could NOT see the central star!
I ache, therefore I am
12.5" Home built F-4.8 Eq Newt. Lightholder Optics mirror 12'x12' roll-off roof observatory 6" Home built f-6 Newt. w/Dick Wessling mirror on CG-5 Eq. mount. 4.5" Orion Starblast My equipment philosophy... If it ain't broke, fix it anyway.
Ken Fiscus- stargazing since 1980. Now observing from a green zone.
Z12 on custom mount, Atomic EQ platform, 100% flocked, OMI primary, Astrocrumb filter slide with O-III, NPB, & skyglow filters. Focuser & spider rotated 45 degrees. New springs & Bob's Knobs, Telrad & 9x50 straight finder 35 & 24 Pans, TV 13,7,5 T6s
Custom Orion XT10 with piggyback XT4.5 on Round Table EQ Platform
Present gear: 16-inch f/4.5 Dobsonian 50mm straight through-finder Green laser pointer 26mm, 32mm, and 38mm 70 degree field EPs 4.7mm, 14mm and 18mm 82 degree field EPs 8mm, 17mm, 21mm 68 degree field EPs 2X 2" Barlow Tirion star atlas (white stars, black background) hand-laminated Megastar Editor & co-founder Las Vegas Astronomical Society Observer's Challenge To nudge or not to nudge, that is the question www.fredrayworth.com
Quote:ok... thanks a lot to everyone for weighing in on this one. We still got a problem. No map to the whereabouts of this terrestrial sized 15th magnitude white dwarf that shines in uv and blue. Tomorrow when I get back home I'll look into this. If you got time to look into this that'd be awsome. There are still mysteries in one of the most popular objects on anyones list! Amazing!
Quote:So the central star of M57 catalogued at mag. 14.7 should be an easy object for me, right? No, it isn't. The "bright" background of the nebula makes it very difficult indeed ... perhaps more magnification might help ... I find the mag. 13 star just outside the ring to be really easy with 11" and can see it fairly easily with 4.3". My suspicion is that the magnitude of the central star is catalogued incorrectly.
Quote:I am skeptical of most claims. The only reported observation that I 100% accept is by my older son, who observed it in a 60" scope on Mt. Lemmon. He says that it was not super easy to see. Of course, my skepticism doesn't make other claimed sightings false, and everybody decides for themselves who and what to accept, and with what degree of certainty. I do know that it is very easy to see what you want to see, especially if you know the exact location of the target.
Quote:Here is a magnitude chart of surrounding stars. If you can't see some of these, you won't see the center star.
Quote:Again, the keys to viewing M57's central star are:1. modestly dark skies (and good dark adaptation).2. apertures larger than eight inches.3. very high power (well over 300x).4. very stable seeing.5. watch for an extended period of time.
Quote:It is OK to be somewhat skeptical sometimes, but in this case, the truth of the matter is, the central star of M57 can indeed be seen in amateur telescopes.
Quote:I will try watching M-57 for an extended period to see if it becomes visible that way.Taras
Homemade 14.5" f4.3 Truss Dobsonian
"I'd like to remind you at four in the morning my world is very still, The air is fresh under diamond skies, makes me glad to be alive." Randy Bachmann "Blue Collar"
“A mind is like a parachute. It doesn't work if it is not open.” ― Frank Zappa
LS60THa/B1200 Cerevolo 8" F5 MN Orion 11 SCT Tak EM200, Meade 6" F5 Newt, Starblast 4.5", ETX 90 C6 SCT, Meade 90 mm F9 refractor Meade 10"SN Canon T3, Mallincam Extreme
6'' Orion SkyQuest f/5 12.5" Astrotel truss dob f/3.3 20" Super FXQ Starmaster William Optics 80mm ZenithStar ED II 1855/2500 Observing sessions grand total for 2013, 49. So far in 2014, 14
Quote: Some say the star is variable in brightness and this may play a role in it's visibility.
Quote:Point 3: I'm skeptical of the need for more than 20x per inch of aperture. It's at about this point that the diffraction disc of a point object (star) starts to become extended and there is no further gain in contrast between star & background by going higher. Smearing out the star tends to reduce its visibility in the same way that poor seeing does.
I performed experiments during good seeing, and the results were that unless the power is fairly high, the star remains invisible. In my 10 inch f/5.6 Newtonian, I was unable to see it if the power was less than 300x (I was at 288x when doing the experiment), and it was decidedly easier to pick up at powers above 350x. In fact, most of the time when trying for the star, I use from 384x to 471x even in my 14 inch. It just takes a bit more power to dim down the interior glow of the nebula and let the star stand out a bit more, especially considering the low resolution of the dark adapted human eye using averted vision. The consensus among most experienced deep-sky observers is that to see the central star, something over 300x is often necessary. Indeed, Brian Skiff has recommended something closer to 500x:
Photometry of M57 Field Stars
Clear skies to you.
Quote:Quote:Here is a magnitude chart of surrounding stars. If you can't see some of these, you won't see the center star. Uh, that's MY chart BTW.... (prepared from a DSS image I processed with photometry provided by Brian Skiff of Lowell plus other sources).
C-11 SCT, XT10i Dob, C-6 SCT, ETX125PE Mak-Cass, TV102, & AT66
"We the People are the rightful master of both congress and the courts - not to overthrow the constitution, but to overthrow the men who pervert the constitution." Abraham Lincoln"
The heavens declare the glory of God; the skies proclaim the work of his hands." Psalms 19:1
My Blog http://buddybarbee.wordpress.com
Refractors Reflectors Two Cats A few eyepieces
A man is a small thing, and the night is very large and full of wonders.
John Hayes, Ph.D.
Adjunct Research Professor
College of Optical Sciences
University of Arizona
Quote:The central star is quite blue.. Integrated magnitude may be 14.6- 15.0. Visual it is 15.8-16.0 or even fainter. A good bit of the energy is in the far blue end of the spectrum as the surface temperature is about 100,000K. If you are a little older it might be more difficult. The spectral distribution makes it difficult. That being said, I saw it one time from a green Zone 30 years ago in a 16" F5 Cave. Seeing and transparency were very good that evening.We used a 5mm Clave' and a Barlowed 10.5mm RGO (mine) about 400x. It was not visible under about 300x.
Quote:...Viewing the central star in M57 depends largely on the stability of the atmosphere, so if seeing isn't rock-solid, you won't see it no matter how big the telescope is. Clear skies to you.