6
$\begingroup$

I am a beginner and I am using a Celestron AstroMaster 114 telescope. Whenever I try to view distant planets such as Jupiter I am presented with a black circle that has black lines leading from it. In between these lines is a white blur. When I focus the telescope using the focus knob, the black circle along with the white blur shrink to the size of a star in the night sky before becoming larger. I don't have this viewing the moon and in fact was able to see a very breathtaking image of it. I am using the star finder with the red dot and I have aligned it during the day so my star finder and my telescope are looking at the same thing. Any help would be greatly appreciated.

$\endgroup$
5
  • 6
    $\begingroup$ What eyepiece are you using? It sounds like you're just using a low power eyepiece and aren't seeing details on Jupiter. $\endgroup$ Commented Jan 7, 2022 at 4:37
  • 3
    $\begingroup$ Can you Post an image, please? $\endgroup$ Commented Jan 7, 2022 at 21:58
  • $\begingroup$ @GregMiller I had this exact same thought. I am using a 20mm and a 10mm. I switched from the 20 to the 10 and I still get a tiny little white dot that is the same size despite the change in eyepiece. $\endgroup$
    – Keegan
    Commented Jan 8, 2022 at 4:25
  • $\begingroup$ Some telescopes (e.g. Cassegrain) don't have vanes and support the secondary on a glass window (lens) instead. Then you just get a "donut". See for example What is that donut-shaped object I see in my telescope? and Help identify a bright and round object photographed through a telescope and my goodness all of these as well! $\endgroup$
    – uhoh
    Commented Jan 8, 2022 at 5:12
  • $\begingroup$ If your telescope is in focus when you look at the Moon, it will be in focus when you look at Jupiter (unless you change the eyepiece). $\endgroup$ Commented Jan 10, 2022 at 12:03

3 Answers 3

9
$\begingroup$

Jupiter and the four largest moons are easily viewable with 8x to 10x binoculars, so I think the first step is to read the manual to learn how to set the focus to infinity. I'm rather surprised that there's much change in the focus knob between lunar and Jovian observation in the first place!

I agree with the other answers that you are somehow seeing the secondary & its mounting "spider", which suggests that you either have a significant misalignment or more likely are massively out of focus.

$\endgroup$
4
  • $\begingroup$ I did some digging and was reading that I should be in focus when the white blur becomes defines and the black circle disappears. Once I have this white dot when I trying to look at Jupiter, is that Jupiter? $\endgroup$
    – Keegan
    Commented Jan 8, 2022 at 1:06
  • 1
    $\begingroup$ @Keegan If it is jupiter, You must be seeing 4 or atleast 2 small dots aligned next to the Big dot in a straight line have you observed that ? $\endgroup$ Commented Jan 8, 2022 at 4:19
  • $\begingroup$ @kevinIshwaran Please forgive the delayed response, it has been cloudy for the past couple nights. I believe I have found Jupiter and two moons but that was with the 10mm eyepiece and still Jupiter was a tiny white ball. Notice I say ball so I believe I found the giant gas planet but shouldn't I be able to see more than a white ball when looking? Is the 10mm eyepiece not sufficient for viewing planets in great detail? Should I look into a 4mm eyepiece? $\endgroup$
    – Keegan
    Commented Jan 14, 2022 at 6:17
  • $\begingroup$ @Keegan Sorry for this very late response since I didnt get a notification of your Comment. I think it should be in focus since if you can see the two moons but not the ribbons means that you are observing in a wrong place and in a wrong time, the moons will not be visible like a star jf it ia out of focus given that the setup is of a 114mm aperture and 10mm eyepiece. If you cannot see the ribbons with the 10mm eyepiece, its not advisible to go for a 4mm. We need to conclude if it is due to weather conditions $\endgroup$ Commented Feb 11, 2022 at 13:20
9
$\begingroup$

What I can understand is, you are seeing the secondary mirror and the vanes while observing Jupiter, it is not a big problem since it arises only in you are not having the Jupiter in focus. In fact those "black lines" and "black circle" will help you collimate your telescope for better viewing experience. And if you want to see Uranus with a 114mm aperture telescope, I won't say you can't see it, but what you will see will be a dim star like object which may actually be Uranus. I don't know if you can see the greenish-blue colour. Sorry to have a pessimistic view. Good luck!

$\endgroup$
6
  • $\begingroup$ I appreciate your advise. If my problem is that I am seeing the secondary mirror would this be adjusted using the collimation screws on the telescope or the focus knobs near the eyes piece? $\endgroup$
    – Keegan
    Commented Jan 7, 2022 at 17:57
  • $\begingroup$ @Keegan You should see the secondary when out of focus. When a bright star is in the center of the field of view and out of focus, the secondary should be in the center of the blurry star. If the star isn't centered, the secondary won't be, so center the star carefully when doing this kind of test. BTW, I've seen Uranus in a 60mm scope. It's theoretically visible naked eye under very good conditions. $\endgroup$ Commented Jan 7, 2022 at 21:41
  • $\begingroup$ @TechInquisitor When I view Jupiter and all I see is a fate white blur accompanied by a black circle and black lines and when I move the focus knobs these lines shrink and the white light becomes small and clearer, is this Jupiter? How would I go about correcting this issue? $\endgroup$
    – Keegan
    Commented Jan 8, 2022 at 0:36
  • $\begingroup$ @Keegan Yes I guess it is jupiter, I think Celestron's 114eq comes with 20mm and 10mm , use 10 mm or the lowest number written on eyepiece you got, and you should be able to see jupiter since 20mm is a low power eyepiece, and collimation is needed only if your image is hazy or chromated which will, until your image is fine you dont need to touch it. $\endgroup$ Commented Jan 8, 2022 at 4:13
  • $\begingroup$ @KavinIshwaran I've switched between a 20mm and a 10mm and the image looks the exact same. I will try and post a picture tomorrow but it may be challenging since Jupiter is very low in the sky where I live currently $\endgroup$
    – Keegan
    Commented Jan 8, 2022 at 4:29
4
$\begingroup$

Is it four black lines at right angles from each other? Perhaps the black circle is the secondary mirror, with the unfocused target making the white blur. If so, first try focusing on something fainter, perhaps a double star or a cluster. Then swing back to Jupiter without changing focus. Also try varying the distance between your eye and the eyepiece lens.

$\endgroup$

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .