A Question from a Night-Sky Newbie

[emperor_of_localgroup]

<p><font size="2">What planet did I see tonight (7-17-08) with my 4+" refractor from Carolinas?&nbsp; It was the brightest dot in night sky next to our moon. Did I also see the planet's 4 moons? Or I need to get my eyes examed soon? Two of the moons were very close to the planet and the other 2 were a little far from the planet, all 4 appeared as bright dots.</font></p><p><font size="2">I'm just trying to verify that my telescope is working fine.&nbsp; And what is the deal with my 8" reflector telescope? The other night I looked at the same planet (I think)&nbsp; next to our moon with my 8" reflector, all I saw was a small bright dot as opposed to a&nbsp; bright ball&nbsp; I saw tonight with my smaller refractor. Did I waste my money buying a reflector? (I borrowed the refractor)</font></p> <div class="Discussion_UserSignature"> <font size="2" color="#ff0000"><strong>Earth is Boring</strong></font> </div>

 

[votefornimitz]

<p>You saw Jupiter...</p><p>And Yes, those were four of its moons</p><p>The Galilean Moons, as they are known, Io, Europa, Ganymede and Callisto. </p><p>&nbsp;</p><p>Generally reflectors are better for deep sky objects and refractors are better for the solar systems objects, but I can't imagine not being able to make out Jupiter and its moons with an 8" Dobsonian, atleast I hope not, as I am switching from my relfector to one of those next week... </p><p>&nbsp;</p> <div class="Discussion_UserSignature"> <span style="color:#993366">In the event of a full scale nuclear war or NEO impact event, there are two categories of underground shelters available to the public, distinguished by depth underground: bunkers and graves...</span> </div>

 

[3488]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'><font size="1" color="#ff0000">You saw Jupiter...And Yes, those were four of its moonsThe Galilean Moons, as they are known, Io, Europa, Ganymede and Callisto. &nbsp;Generally reflectors are better for deep sky objects and refractors are better for the solar systems objects, but I can't imagine not being able to make out Jupiter and its moons with an 8" Dobsonian, atleast I hope not, as I am switching from my relfector to one of those next week... &nbsp; <br />Posted by votefornimitz</font></DIV></p><p><strong><font size="2">The Galileans are visible in normal 7 x 50 Binoculars & even opera glasses.</font></strong></p><p><strong><font size="2">Ganymede is the brightest, Callisto despite being almost equal in size to Ganymede, Titan & Mercury is the faintest. due to the large amount of dark surface dust. on the cratered surface.&nbsp;Europa is brilliant white (to be expected being covered in ice)&nbsp;& Io can actually look yellowish (sulphur from the volcanoes) under excellent seeing, though normally appears white, just a little fainter than Europa.<br /></font></strong></p><p><strong><font size="2">I have seen them a great many times & never get bored. The Jupiter system is my favourite both observationally & scientifically, though the Saturn system is not far behind.</font></strong></p><p><strong><font size="2">Worth mentioning, that not all four will be visible all of the time. Oftem one or more can pass infront of (transit) Jupiter, or pass behind (occulted) the giant planet & at times hide each other. On one occassion, quite some time ago, Jupiter appeared moonless for a very short period, because all four galileans were either transiting, occulted, etc at the same time. Sometimes they may appear in order on one side Io, Europa Ganymede & Callisto, or even in reverse order, due to the line of site effect, two on each side, one on one side, three on the other, etc, always changing.</font></strong></p><p><strong><font size="2">Andrew Brown.</font></strong></p> <div class="Discussion_UserSignature"> <p><font color="#000080">"I suddenly noticed an anomaly to the left of Io, just off the rim of that world. It was extremely large with respect to the overall size of Io and crescent shaped. It seemed unbelievable that something that big had not been visible before".</font> <em><strong><font color="#000000">Linda Morabito </font></strong><font color="#800000">on discovering that the Jupiter moon Io was volcanically active. Friday 9th March 1979.</font></em></p><p><font size="1" color="#000080">http://www.launchphotography.com/</font><br /><br /><font size="1" color="#000080">http://anthmartian.googlepages.com/thisislandearth</font></p><p><font size="1" color="#000080">http://web.me.com/meridianijournal</font></p> </div>

 

[MeteorWayne]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>What planet did I see tonight (7-17-08) with my 4+" refractor from Carolinas?&nbsp; It was the brightest dot in night sky next to our moon. Did I also see the planet's 4 moons? Or I need to get my eyes examed soon? Two of the moons were very close to the planet and the other 2 were a little far from the planet, all 4 appeared as bright dots.I'm just trying to verify that my telescope is working fine.&nbsp; And what is the deal with my 8" reflector telescope? The other night I looked at the same planet (I think)&nbsp; next to our moon with my 8" reflector, all I saw was a small bright dot as opposed to a&nbsp; bright ball&nbsp; I saw tonight with my smaller refractor. Did I waste my money buying a reflector? (I borrowed the refractor) <br />Posted by emperor_of_localgroup</DIV><br /><br />Did you use you highest power eyepiece ( lowest "mm size" ) with the 8" reflector? If you use a low power eyepiece even with the larger scope it can appear smaller. <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[emperor_of_localgroup]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>You saw Jupiter...And Yes, those were four of its moonsThe Galilean Moons, as they are known, Io, Europa, Ganymede and Callisto. &nbsp;Generally reflectors are better for deep sky objects and refractors are better for the solar systems objects, but I can't imagine not being able to make out Jupiter and its moons with an 8" Dobsonian, atleast I hope not, as I am switching from my relfector to one of those next week... &nbsp; <br /> Posted by votefornimitz</DIV></p><p><font size="2">Thanks, guys. It was a sigh of relief for me. Finally I saw something right.&nbsp; I was so frustrated with my 8" reflector, I had to borrow the 4" refractor and still don't know what is wrong with my Nexstar 8i. Although I can see details of our moon better with 8" reflector than 4" refractor, but planets and deep sky stars&nbsp; look better with naked eyes than with 8" reflector.&nbsp; I know something's wrong. (yes, I see more stars with either tel). </font></p><p><font size="2" color="#ff0000">Did you use you highest power eyepiece ( lowest "mm size" ) with the 8" reflector? If you use a low power eyepiece even with the larger scope it can appear smaller. [Meteor]</font></p><p><font size="2">&nbsp;I tried all eyepieces I have, 25mm, 15mm, 9mm, 4mm. 25mm shows me a very bright sharp dot, as I move to 4mm, the dot gets somewhat bigger (but not as big as with refractor), but the sharpness gets lost, and can't see a single Jupiter moon.&nbsp;</font></p><p><font size="2">Anyway, now I can't wait to take a look at Saturn's ring. Anyone knows when will Saturn&nbsp; hang around us and in what part of the sky?</font></p><p><font size="2">&nbsp;</font></p> <div class="Discussion_UserSignature"> <font size="2" color="#ff0000"><strong>Earth is Boring</strong></font> </div>

 

[MeteorWayne]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Thanks, guys. It was a sigh of relief for me. Finally I saw something right.&nbsp; I was so frustrated with my 8" reflector, I had to borrow the 4" refractor and still don't know what is wrong with my Nexstar 8i. Although I can see details of our moon better with 8" reflector than 4" refractor, but planets and deep sky stars&nbsp; look better with naked eyes than with 8" reflector.&nbsp; I know something's wrong. (yes, I see more stars with either tel). Did you use you highest power eyepiece ( lowest "mm size" ) with the 8" reflector? If you use a low power eyepiece even with the larger scope it can appear smaller. [Meteor]&nbsp;I tried all eyepieces I have, 25mm, 15mm, 9mm, 4mm. 25mm shows me a very bright sharp dot, as I move to 4mm, the dot gets somewhat bigger (but not as big as with refractor), but the sharpness gets lost, and can't see a single Jupiter moon.&nbsp;Anyway, now I can't wait to take a look at Saturn's ring. Anyone knows when will Saturn&nbsp; hang around us and in what part of the sky?&nbsp; <br />Posted by emperor_of_localgroup</DIV><br /><br />Sounds like your 8" scope needs to be collimated for one thing. Have you done that? Do you know how to?</p><p>Also, did you gibe your 8" scope enough time to equalize temperatures? It takes at least an hour or more depending on the temperature difference between where it's stored and the outside air temperature. It can't really be rushed </p> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[BrianSlee]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>What planet did I see tonight (7-17-08) with my 4+" refractor from Carolinas?&nbsp; It was the brightest dot in night sky next to our moon. Did I also see the planet's 4 moons? Or I need to get my eyes examed soon? Two of the moons were very close to the planet and the other 2 were a little far from the planet, all 4 appeared as bright dots.I'm just trying to verify that my telescope is working fine.&nbsp; And what is the deal with my 8" reflector telescope? The other night I looked at the same planet (I think)&nbsp; next to our moon with my 8" reflector, all I saw was a small bright dot as opposed to a&nbsp; bright ball&nbsp; I saw tonight with my smaller refractor. Did I waste my money buying a reflector? (I borrowed the refractor) <br />Posted by emperor_of_localgroup</DIV><br /><br />I used to own a Meade 2080B Schmidt/Cassegrain (which&nbsp;uses an&nbsp;8" reflector) with a motor drive.&nbsp; Jupiter and Saturn were fairly spectacular when atmospheric conditions were good&nbsp;. My guess would be that you were not locked on to what you think you were or you were having focus issues.&nbsp; Here is a sample of what&nbsp;should be&nbsp;possible with an 8" reflector</p><p><img src="http://www.bro.lsu.edu/bras/images/wp_jupiter_thumb.jpg" border="2" alt="Download image" width="345" height="242" /></p><p>Credit Baton Rouge Astronomical Society.</p><p>This pic was taken with a 10" dobsonian but is still pretty close to the performance I would get with the 8" on a good night</p> <div class="Discussion_UserSignature"> <p> </p><p>"I am therefore I think" </p><p>"The only thing "I HAVE TO DO!!" is die, in everything else I have freewill" Brian P. Slee</p> </div>

 

[crazyeddie]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'> Although I can see details of our moon better with 8" reflector than 4" refractor, but planets and deep sky stars&nbsp; look better with naked eyes than with 8" reflector. </DIV></p><p>I find this very hard to believe. &nbsp;Any telescope, even a small one, should allow you to see the planets better than you could with the naked eye. &nbsp;Stars will look the same, however....only brighter. &nbsp;If the star happens to be a double or a triple, the telescope will help you split the components that the naked eye could not discern.</p><p>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I tried all eyepieces I have, 25mm, 15mm, 9mm, 4mm. 25mm shows me a very bright sharp dot, as I move to 4mm, the dot gets somewhat bigger (but not as big as with refractor), but the sharpness gets lost, and can't see a single Jupiter moon.&nbsp;Anyway, now I can't wait to take a look at Saturn's ring. Anyone knows when will Saturn&nbsp; hang around us and in what part of the sky?&nbsp; <br /> Posted by emperor_of_localgroup</DIV></p><p>A 4mm eyepiece gives too high a magnification for this telescope's abilities. &nbsp;Low-power views are almost always sharper than high-power views, if all the eyepieces are of similar design and quality. &nbsp;It's possible you didn't see any of Jupiter's moon because you happened to view it at one of those rare times when all four were either in eclipse or in front of the big planet's disk.</p><p>I suggest that you invest in a subscription to Astronomy or Sky and Telescope magazine, or Night Sky, which is for beginners. &nbsp;They all have maps that show you what is visible in the skies each month, and where.&nbsp;</p> <div class="Discussion_UserSignature"> </div>