Mars moons, Phobos & Deimos

[MarsG76]

Hello All,

Tonight and hopefully tomorrow night I was planing to see Phobos and/or Deimos.

I have two windows of opportunity tonight, at 20:50-21:20 AEST and 00:30-01:00 to see Phobos and tomorrow around 20:00 to see both Phobos and Deimos.

I covered half of my Ethos eyepiece opening with electrical tape to put Mars behind and look for Phobos. The shield worked a charm, but still Phobos did not pop into view at all.

Visually I was unsuccessful to see Phobos tonight but imaging at 1/15th second exposure I might have not only caught Phobos, but also Deimos coming around from the glare of Mars.

 The attached image was exposed one for Phobos, 1/15th sec with gain set at max gain and for Mars I exposed a 1/313th sec @ 60fps and no gain than combine both in photoshop.

I'm hoping to give it another go at 00:30-01:00.

Clear skies,

MG

 

[Knighty2112]

Excellent wok MarsG76!  

[MarsG76]

2 minutes ago, Knighty2112 said:

Excellent wok MarsG76!  

I might have another one and a potential confirmation of it being a moon.... basically if the point of light is on the other side at 00:40sh than that has to be Phobos. And if the other dot has moved than it is Deimos.... hopefully the clouds stay away.

 

[Demonperformer]

Great result. Presumably with the 8SE? It was something I was hoping to have a go at, but every time both satellites were at a reasonable distance from the planet, conditions did not allow for an attempt. Still, as a northerner, this gives me great promise for the October 2020 apparition.

[Demonperformer]

2 minutes ago, MarsG76 said:

I might have another one and a potential confirmation of it being a moon.... basically if the point of light is on the other side at 00:40sh than that has to be Phobos. And if the other dot has moved than it is Deimos.... hopefully the clouds stay away.

 

If you have Cartes du Ciel, you should be able to get the positions of the moons from your location at the time you took it.

[MarsG76]

Just now, Demonperformer said:

Great result. Presumably with the 8SE? It was something I was hoping to have a go at, but every time both satellites were at a reasonable distance from the planet, conditions did not allow for an attempt. Still, as a northerner, this gives me great promise for the October 2020 apparition.

Yeah it's with the 8SE... My 14" is inside waiting until I have a bit of time to spend on collimating those mirrors into perfection.....

[MarsG76]

Just now, Demonperformer said:

If you have Cartes du Ciel, you should be able to get the positions of the moons from your location at the time you took it.

AHHHHH YES... Thanks for the tip.... 

[Demonperformer]

Assuming I haven't screwed up the time calculations [and the star looks in about the right place], it looks as if you might have labelled the moons backwards?

[MarsG76]

3 minutes ago, Demonperformer said:

Assuming I haven't screwed up the time calculations [and the star looks in about the right place], it looks as if you might have labelled the moons backwards?

So it is the moons... interesting that the moons are backwards since I got the time estimates from Astronomy Now magazine and the said that Phobos was at western elongation at 10:54UTC... 

Do me a favour and have a look at 14:42, which is meant to be Photos at eastern elongation???

[Galen Gilmore]

Damn, that is impressive. I don't think that I will be seeing the martian moons anytime soon, at least not with my gear.

[Demonperformer]

Hang on a minute, I think I have screwed up timings.

01:16 UT ... is that UT on 5 Sep (Australia being ahead of the UK)? Then, BST (to which my version of CdC is set) is one hour ahead of UT, so it would be 02:16 BST not 00:16, as I did before. And with the speed at which Phobos moves (about 3h40m from elongation to elongation on the other side) the screenprint I produced is probably WAY out.

So here is one for 02:16 BST 5 Sep (01:16 UTC), which would make the object labelled Phobos the (15th mag!) star and what I thought was a star close to Mars, Phobos.

The other thing that might be confusing things is the orientation through the sct>camera. The image here is right/left inverted and up/down correct.

Once we have ascertained I am at least looking at it at the right time and in the right orientation, I will check your other time.

[Demonperformer]

I'm sorry, I am talking such a load of rubbish ...

21:16 4/9 AEST is 12:16 4/9 BST (got this from the internet). Here is a CdC screenprint for that time with no changes made to orientation at all. The red circle is a 1.0' fov.

The star on the far left side of the screenprint is UCAC4-322-213754 (mag 11.57) and the star near the 5 o'clock position of the circle is UCAC4-322-213772 (mag 16.34). Measuring your photo, that is a pretty good approximation for your label Phobos being UCAC4-322-213754 & your label Deimos being Phobos, which is quite a long way east of Mars.

[Demonperformer]

And here is a screenprint for 20:00 AEST 05/09 ... which seems to fit in with your prediction "to see both Phobos and Deimos". The stars in this one are all mag 15 and fainter, so P&D should be the brightest things in the area.

Hopefully I have managed to finally produce something that is (1) right and (2) useful. All you need now is a clear sky ...

[MarsG76]

1 hour ago, Demonperformer said:

And here is a screenprint for 20:00 AEST 05/09 ... which seems to fit in with your prediction "to see both Phobos and Deimos". The stars in this one are all mag 15 and fainter, so P&D should be the brightest things in the area.

Hopefully I have managed to finally produce something that is (1) right and (2) useful. All you need now is a clear sky ...

We both stuffed it up... I went outside to get some more data. When inside I double checked both captures against CdC and below is what I got...

[MarsG76]

I need to do a correction to the first labelling when comparing to CdC... I stated that its 1:16 UTC 4 September but in actual fact its 11:16 UTC...

 

 

The "star" below that I assume is Phobos in this correction might be Deimos since the size or Mars to the moons doesn't seem to the to scale.

 

[MarsG76]

I went out again to try at imaging the Martian moons again at 00:30 AEST and this is what I ended up with....

 

 

No sign of Deimos... but Phobos in the right spot.

 

 

AND with this post I have entered the "Main Sequence" with my 5000th post..... 

[Demonperformer]

Congratulations on both.

[Dave1]

Impressive indeed, well done MarsG76

[orion25]

Bravo, Mars! The imaging continues...

[Demonperformer]

10 hours ago, MarsG76 said:

No sign of Deimos... but Phobos in the right spot.

Taking another look at this, I am rather surprised that you did not get Deimos. It was roughly twice the (angular) distance from Mars as Phobos [so the glare would have been less of a problem] and the star is (I presume) UCAC4-322-213831, which at mag 15.76 is ~2.8 mag fainter than Deimos (mag 12.9). Going to take a bit of pondering methinks.

[MarsG76]

1 hour ago, Demonperformer said:

Taking another look at this, I am rather surprised that you did not get Deimos. It was roughly twice the (angular) distance from Mars as Phobos [so the glare would have been less of a problem] and the star is (I presume) UCAC4-322-213831, which at mag 15.76 is ~2.8 mag fainter than Deimos (mag 12.9). Going to take a bit of pondering methinks.

I was thinking the same thing, Deimos is bigger, brighter and further away from the glare of Mars and yet I did not capture it....

During the capture I did pan east/west looking for Deimos being outside of the frame but I did not come across anything so I captured the frame with Mars in this position.

I guess it is what it is, but I will try again in the near future, weather permitting, this time I'll use my DMK41 with the bigger FOV and higher resolution.

[MarsG76]

1 hour ago, Demonperformer said:

Taking another look at this, I am rather surprised that you did not get Deimos. It was roughly twice the (angular) distance from Mars as Phobos [so the glare would have been less of a problem] and the star is (I presume) UCAC4-322-213831, which at mag 15.76 is ~2.8 mag fainter than Deimos (mag 12.9). Going to take a bit of pondering methinks.

Although I'm quite happy with the initial result. I was hoping to catch a glimpse of any of the moons in the eyepiece, without success, and using the Astronomy Now extrapolated predictions and the flash based web site which showed the position of Mars' moons and the direction of Earth, I was really only hoping to see Phobos, since from my location at night time only Phobos was in its greatest elongations, the next night, ie Tonight is supposed to be where Phobos and Deimos are at their greatest elongations... but right now it's looking totally over cast, so we'll see how that pans out.

Thanks for the tip about CdC showing the positions of Mars moons, I haven't even though of CdC since I didn't use it much, but it'll be a great help in the future hunt... I'm just regretful that I got the idea to hunt Mars' moons so late in the season.

[MarsG76]

1 hour ago, Demonperformer said:

Taking another look at this, I am rather surprised that you did not get Deimos. It was roughly twice the (angular) distance from Mars as Phobos [so the glare would have been less of a problem] and the star is (I presume) UCAC4-322-213831, which at mag 15.76 is ~2.8 mag fainter than Deimos (mag 12.9). Going to take a bit of pondering methinks.

I was hoping to catch a glimpse of any of the moons in the eyepiece, I used my 17mm Ethos with half of it covered with black electrical tape and even though it definitely blocked the glare of Mars, I still couldn't spot Phobos in the EP... and I tried hard, even knowing where it's located.

The one thing that the hunt for Phobos revealed is that I had a very clear, still and transparent night... the view of Mars I had was AMAZING... way better than the last "best view of Mars ever" I had last time.... The dark markings were as obvious as the nose on my face, the polar cap glowed, the Y/bikini shape was like some kind of a "car logo" with various shades of orange/pinky throughout the huge disc... even using the 5mm X-Cel ep showed Mars massive and clear at 406X magnification.... the disc was so big and detailed that I really took almost no effort to see the features, and the eye floaters were no problem...WOW. 

Using the Baader Neodymium and Contrast booster filters really do reveal a staggering amount of planetary detail when the seeing is so good.

 

[Demonperformer]

I would be surprised if it were a FOV problem - the M/D distance appears to have been about twice the M/P distance and on roughly the same line as star-Phobos. That point would appear to be well within the frame.

Years back in read that it required at least a 12" aperture to view the Martian moons, but scopes have improved a bit since the 60s so it may be possible with an 8" today. Either way it is good you got such a great view if the planetary detail.

[MarsG76]

23 hours ago, orion25 said:

Bravo, Mars! The imaging continues...

Definitely does... now to do a 4 hours time lapse of the moon orbiting Mars...