Pluto

Getting a shot of Pluto has been a long-held ambition of mine, and with it in the news and only just past opposition, a good clear night last night gave me my chance. At a declination of -20 deg it's very low in the sky from UK. I used my Celestron 8" Edge HD with 0.7x matched reducer, giving 1400mm at f/7, and my 7D set at ISO3200. Stacking 16x30s exposures gave me a very useful limiting magnitude of 16.9, which I was pleased with so low in the sky (it must have been clearer air than we normally get here!). I think the atmosphere probably accounts for the slight colour separation on the brighter stars. Anyway, with quite a bit of effort, looking at finder charts and comparing my frame with Wikisky, I positively identified the dwarf planet, 3 billion miles away. This is a crop of a little less than half the width of the original frame.

Incredible and congratulations!!!!!

Very cool!

I thought about attempting the same, but there's quite a bit of skyglow in the direction I would have to shoot from my site, so I saved myself the grief.

Although... I do have an Astronomik CLS clip in filter. Maybe I'll give it a shot next time conditions are favourable.

Where's Charon?

Where's the probe flying by?

Unbelievable by the way.

Congratulations Mark ! Very few images have been produced from a telescope . This is one image that proves "You Do Need A Telescope" if you are into astronomy . I have never been able to spot Pluto or Neptune . I have seen Uranus and imaged it also . That was exciting as it was but I can image how you felt when Pluto showed up ! Don't let the others that joke about it bother you . There is always some jokers in the deck .

Very interesting

Congratulations.

Congratulations but how are you sure about this

Madweasel wrote in post #17635372
Getting a shot of Pluto has been a long-held ambition of mine, and with it in the news and only just past opposition, a good clear night last night gave me my chance. At a declination of -20 deg it's very low in the sky from UK. I used my Celestron 8" Edge HD with 0.7x matched reducer, giving 1400mm at f/7, and my 7D set at ISO3200. Stacking 16x30s exposures gave me a very useful limiting magnitude of 16.9, which I was pleased with so low in the sky (it must have been clearer air than we normally get here!). I think the atmosphere probably accounts for the slight colour separation on the brighter stars. Anyway, with quite a bit of effort, looking at finder charts and comparing my frame with Wikisky, I positively identified the dwarf planet, 3 billion miles away. This is a crop of a little less than half the width of the original frame.

chaturanga wrote in post #17641424
Congratulations but how are you sure about this

Mmmm, looks to me like Madweasel did his homework. Just from his description of his equipment, how he acquired the image, and how he processed the image it seems that he is knowledgeable about astronomy and astro-photography. I suppose he could have went to extremes to verify the capture,...but, being a personal challenge to him, why would he if he's satisfied (and excited) about the capture?

Btw, I'm not giving you a hard time about your inquiry, just stating that I think he confirmed it "good enough" for his confidence in what it is. Star maps are pretty constant so for someone who is knowledgeable it is relatively easy to see a "moving" object among the star field. I'm definitely not educated in all of this, but I think Madweasel has more than a rudimentary knowledge.

Ed

I might also add to what Ed (Intheswamp) is verifying . A decent Go-To scope of a larger size (8" or bigger) are extremely helpful in finding many and most all objects in the sky . Planets are easiest to track when they are above the horizon and high enough to see over tree tops and house tops . The farther away a planet is out in orbit the slower it will move because it has such a vast orbit around the sun .

Planetarium software is extremely helpful in finding where objects are located in the sky and when they are available for viewing . Sky charts also are very helpful for locating night objects and if you have a star chart that shows down to 20 magnitude you can compare stars seen through a scope with your star charts . Usually this takes a dedicated amateur astronomer who knows how to read star charts and does a lot of viewing through their scopes besides just attaching a camera and taking a picture of what is available .

Now many objects are available without a telescope and many can be taken with short exposures that can be stacked but many of those call for costly equipment like a tracking mount of some type that can cost upwards close to $1000.00 when included with their tripod . And then to add to that some use telephoto lens and some costing into the thousands of $$$ . But one must still have some knowledge of the night sky of how to set it up and align it for imaging and then they are still limited .

However many objects such as Uranus , Neptune and Pluto in the sky cannot be verified with the above setup because of limitations . If a planet has color that can help but when taking images that are long exposures can burnout a planet making it look like any other star cause the color is not there in burnout images . The only exception is having star charts or Planetarium software and taking images of the same night sky section and comparing the images to see if a particular star has moved over a period of time .

Pluto is a good example . Pluto will stay in the same section for many months and looks like it never has moved but in a good scope you can definitely see the movement over a few weeks interval . I'm not talking about like watching Jupiter rotate over a couple hours period of time . Even in a scope you can locate Pluto and study the stars around it and then go back in a week or two or even a month and you will be able to see how far it has moved from the first location but you will not see movement during the first 24 hours of locating Pluto .

Many other night sky objects such as comets and asteroids on the other hand are completely opposite . They move at such a high rate and sometimes either in the opposite direction of earths rotation or they can be very close to earths orbit that movement can be seen watching it in a good scope over a matter of a couple hours viewing time and some depending how fast they are traveling in a matter of minutes . Some comets are naked eye but will never be in the same spot every night and can disappear from vision quickly !

Sorry for rambling on but a long story short , Not ALL objects in the night sky can be seen without a Telescope . Taking pictures from a tripod even with a tracking device cannot capture all objects in the sky . Even prime lens of 600-800mm without being very costly ! Telescopes ARE necessary to have if your going to study the night sky and learn what all is actually out there . But for the most part reguardless what setup you have you MUST have good star charts for comparison as well as good planetarium software . The ONLY WAY TO PROVE MOVEMENT of far away objects such as Pluto is By TIME and COMPARISON .

I'm not down grading the technique of using just a tripod and a tracking device , I've seen some excellent images here in this forum . But what is missing is the real excitement of Night Time Observing with a real telescope and actually seeing what is in our Night Sky out in Deep Space WITH our eyes' and not just in images that a camera produces .

Yes you can see all the pictures ever taken by some of the biggest ever scopes and the Hubble but until you actually get involved and get a real scope and star view the night sky and see with your own eyes' and not the cameras' viewer or results of output images you will never truly know the excitement of what a real amateur astronomer experiences doing just what I have always asked and encouraged ! How is the viewing through the EP with your scope ?? I'll never forget the first time I saw Saturn through a 16" SCT at the McDonalds Observatory at Ft.Davis Texas . It blew me away and I was hooked from that day til now ! You cannot replace that feeling with a camera on a tripod or a picture of Saturn taken through a scope . Seeing with my own eye's are just magnificent !!!

Well said, Celestron. The first (and only) time I saw Saturn through a telescope it floored me. I've seen better pictures of it in magazines and such, but standing there in the night and realizing that I was looking at another planet was just *too cool*!!!!!!!!

Ed

Thanks very much everyone for your supportive comments. It's a natural enough question, "How can you be sure?" when Pluto just looks like one of hundreds of other stars in even this small piece of sky. Well, Wikisky, which I used on the image above, is easily good enough to enable me to spot a "star" where there isn't one in the charts, but to satisfy any doubters here is the result of comparing the above shot with another I took four days later. The two halves of the image show exactly the same piece of sky and the arrows show Pluto's movement against the stars.

Interestingly, as someone said above, Pluto's actual movement is very small, since it takes 248 years to cover the whole 360 degrees of its orbit. Almost all of the movement shown here is due to the Earth's shifting position as it moves in its own much faster orbit. These images are "right way up", so Pluto is seen to be moving westwards; what astronomers call "retrograde" motion, opposite in direction to its orbital motion, because the Earth is effectively passing Pluto on the inside.

...and you see I did pick out the right "star" in the first image!

way cool shots, excellently done!

Thanks for the comparative illustration, Madweasel!!! Very educating. Well done!

Ed