Jupiter Last night - 5 moons?

[Patw#73]

About 11.30 last night I had a good clear view of Jupiter with the 4 galileans clearly visible - with Io and Europa really close to each other, really impressive in itself.

However, I was sure that I could see something else. On the same side of Jupieter's globe as IO and Europa (viewed through a SCT) at about seven o'clock I could see a speck of light, about the same distance away as Callisto was at the time. (Sorry I can't give the distances in degrees etc).

Question is, was this a fifth moon or was it a star?

Cheers

[dark knight]

We only saw 4 moons last night.

[dweller25]

Well spotted - It was a mag 8.75 star.

[Doc]

I agree we can only see 4 of Jupiter's moons. Shame really as it has alot more.

[Patw#73]

Can't say I'm not a little disappointed. I reall thought I'd got one there!

What's the likelyhood of coming across any of the other moons?

I'm using an 8" SCT.

[Doc]

Even the largest scopes can only see the top four moons. The rest are:

Io

3,643 kilometers diameter

421,800 kilometers from Jupiter

Europa

3,122 kilometers diameter

671,100 kilometers from Jupiter

Ganymede

5,262 kilometers diameter

1,070,400 kilometers from Jupiter

Callisto

4,821 kilometers diameter

1,882,700 kilometers from Jupiter

Prograde Irregular Satellites

Themisto (S/2000 J1): 9 kilometers diameter; 7,507,000 kilometers from Jupiter

Leda: 18 kilometers diameter; 11,165,000 kilometers from Jupiter

Himalia: 184 kilometers diameter; 11,461,000 kilometers from Jupiter

Lysithea: 38 kilometers diameter; 11,717,000 kilometers from Jupiter

Elara: 78 kilometers diameter; 11,741,000 kilometers from Jupiter

S/2000 J11: 4 kilometers diameter; 12,555,000 kilometers from Jupiter

Carpo (S/2003 J20): 3 kilometers diameter; 16,989,000 kilometers from Jupiter

Outer Retrograde Irregular Satellites

S/2003 J3: 2 kilometers diameter, 18,339,885 kilometers from Jupiter

S/2003 J12: 1 kilometers diameter, 19,002,480 kilometers from Jupiter

Euporie (S/2001 J10): 2 kilometers diameter, 19,302,000 kilometers from Jupiter

S/2003 J18: 2 kilometers diameter, 20,700,000 kilometers from Jupiter

Orthosie (S/2001 J9): 2 kilometers diameter, 20,721,000 kilometers from Jupiter

Euanthe (S/2001 J7): 3 kilometers diameter, 20,799,000 kilometers from Jupiter

Thyone (S/2001 J2): 4 kilometers diameter, 20,940,000 kilometers from Jupiter

S/2003 J16: 2 kilometers diameter, 21,000,000 kilometers from Jupiter

Mneme (S/2003 J21): 2 kilometers diameter, 21,069,000 kilometers from Jupiter

Harpalyke (S/2000 J5): 4 kilometers diameter, 21,105,000 kilometers from Jupiter

Hermippe (S/2001 J3): 4 kilometers diameter, 21,131,000 kilometers from Jupiter

Praxidike (S/2000 J7): 7 kilometers diameter, 21,147,000 kilometers from Jupiter

Thelxinoe (S/2003 J22): 2 kilometers diameter, 21,162,000 kilometers from Jupiter

Helike (S/2003 J6): 4 kilometers diameter, 21,263,000 kilometers from Jupiter

Iocaste (S/2000 J3): 5 kilometers diameter, 21,269,000 kilometers from Jupiter

Ananke: 28 kilometers diameter, 21,276,000 kilometers from Jupiter

S/2003 J15: 2 kilometers diameter, 22,000,000 kilometers from Jupiter

S/2003 J17: 2 kilometers diameter, 22,000,000 kilometers from Jupiter

S/2003 J9: 1 kilometers diameter, 22,441,680 kilometers from Jupiter

S/2003 J19: 2 kilometers diameter, 22,800,000 kilometers from Jupiter

Eurydome (S/2001 J4): 3 kilometers diameter, 22,865,000 kilometers from Jupiter

Arche (S/2002 J1): 3 kilometers diameter, 22,931,000 kilometers from Jupiter

Autonoe (S/2001 J1): 4 kilometers diameter, 23,039,000 kilometers from Jupiter

Pasithee (S/2001 J6): 2 kilometers diameter, 23,096,000 kilometers from Jupiter

Chaldene (S/2000 J10): 4 kilometers diameter, 23,179,000 kilometers from Jupiter

Kale (S/2001 J8): 2 kilometers diameter, 23,217,000 kilometers from Jupiter

Isonoe (S/2000 J6): 4 kilometers diameter, 23,217,000 kilometers from Jupiter

Aitne (S/2001 J11): 3 kilometers diameter, 23,231,000 kilometers from Jupiter

S/2003 J4: 2 kilometers diameter, 23,257,920 kilometers from Jupiter

Erinome (S/2000 J4): 3 kilometers diameter, 23,279,000 kilometers from Jupiter

Taygete (S/2000 J9): 5 kilometers diameter, 23,360,000 kilometers from Jupiter

Carme: 46 kilometers diameter, 23,404,000 kilometers from Jupiter

Sponde (S/2001 J5): 2 kilometers diameter, 23,487,000 kilometers from Jupiter

Kalyke (S/2000 J2): 5 kilometers diameter, 23,583,000 kilometers from Jupiter

Pasiphae: 58 kilometers diameter, 23,624,000 kilometers from Jupiter

Eukelade (S/2003 J1): 4 kilometers diameter, 23,661,000 kilometers from Jupiter

Megaclite (S/2000 J8): 6 kilometers diameter, 23,806,000 kilometers from Jupiter

Sinope: 38 kilometers diameter, 23,939,000 kilometers from Jupiter

Hegemone (S/2003 J8): 3 kilometers diameter, 23,947,000 kilometers from Jupiter

Aoede (S/2003 J7): 4 kilometers diameter, 23,981,000 kilometers from Jupiter

Kallichore (S/2003 J11): 2 kilometers diameter, 24,043,000 kilometers from Jupiter

S/2003 J23: 2 kilometers diameter, 24,055,500 kilometers from Jupiter

S/2003 J5: 4 kilometers diameter, 24,084,180 kilometers from Jupiter

Callirrhoe (S/1999 J1): 7 kilometers diameter, 24,102,000 kilometers from Jupiter

S/2003 J10: 2 kilometers diameter, 24,249,600 kilometers from Jupiter

Cyllene (S/2003 J13): 2 kilometers diameter, 24,349,000 kilometers from Jupiter

S/2003 J14: 2 kilometers diameter, 25,000,000 kilometers from Jupiter

S/2003 J2: 2 kilometers diameter, 28,570,410 kilometers from Jupiter

[dweller25]

Wow Doc, that's an amazing memory you have !!!!

[Doc]

All of the top of my head. pretty impressive eh!

[Patw#73]

Well that's me told!

While we're on about moons - is it possible to see Triton?

[Doc]

Yes I've seen Triton in my 16" dob. It's not easy under light polluted skies but was confirmed by looking at Cartes du ceil. It's very dim at mag 13.5.

[Macavity]

Having made a similar "non-discovery" quite RECENTLY (But with correct hunch-ed), I'm still quite impressed. Perhaps there are quite a lot of instances, where a star masquerades quite well as a Jovian satellite... or NOT, as the case may be?

More common still when, as with Saturn, satellites don't "line up", 'cos of it's axial tilt and there are a few more (mag 10 or so) + Titan (mag 8.3) candidates.

[Patw#73]

I would imagine that Triton is going to remain somewhat elusive for me from my back garden.

I did manage to spot Neptune last night though, which was encouraging.

What sort of mag would you recommend to get the most out of Neptune?

[afm038]

Doc,

What no magnitudes for them

Andy

[Doc]

I would imagine that Triton is going to remain somewhat elusive for me from my back garden.

I did manage to spot Neptune last night though, which was encouraging.

What sort of mag would you recommend to get the most out of Neptune?

Neptunes disk is ony 2.5' across, so to resolve this to a disk I would say at least x250. The higher the better really.

But to see it's moon I found about x150 mag was perfect to see it glimpse in and out of good seeing.

[John]

I spotted Neptune for the 1st time last week with my 4" refractor. At 189x I could discern a disk as opposed to a point of light but it is a very tiny disk !. No chance of Triton with my 4" frac methinks although I have seen a mag 13ish supernova with a 12" dob at the SGL4 starparty so there is hope with my Lightbridge 12" on an excellent night I guess.

John

[lennon890]

Yeah, i saw a planet and four of its moons last night. I didn't really observe it that much because i've only just got my new telescope and i'm still getting use to it. It was either Neptune or Jupiter, It looked like a very bright star to the naked eye and Jupiter is the brightest thing other than the moon so i think that it was Jupiter.

-Lennon890

[Doc]

Yeah, i saw a planet and four of its moons last night. I didn't really observe it that much because i've only just got my new telescope and i'm still getting use to it. It was either Neptune or Jupiter, It looked like a very bright star to the naked eye and Jupiter is the brightest thing other than the moon so i think that it was Jupiter.

-Lennon890

If it had 4 moons and was the brightest light in the sky it was jupiter you saw. Neptune would be very hard to see with the naked eye.