Dump question - Mars is the brightest

[SingleWord]

Is Mars the brightest "star" in the night sky(or evening) observed by naked eye?
Or Venus?

[Allan_L (Allan)]

Originally Posted by SingleWord

Is Mars the brightest "star" in the night sky(or evening) observed by naked eye?
Or Venus?

Taking "Star" to be celestial object, ...

In order of brightness: the sun (magnitude -27), the moon (-12.9), Venus (-3.8), Jupiter (-2.94), Mars (-2.91), Sirius (-1.4), Canopus (-0.7), Alpha Centauri (-0.2), Arcturus (0), Saturn (+0.1). The more negative the apparent magnitude, the brighter the object !

It's not that simple though. For one thing, the sun isn't up at night so it doesn't necessarily make sense to compare it to things that are (even though it is a STAR). And the moon will change brightness with its phases over the course of a month.

Also, the brightness of a planet will vary as it moves relative to or away from the earth, so the order of the list will change quite a bit during different parts of our year and the planets' years. This list is therefore arranged it by how bright the objects get when they're at their brightest.

[SingleWord]

I watched the Saturn crossed the Moon previous weeks and Saturn was so small (10 inch dob, 20mm ep and 2x barlow). So I want to know which is the easiest planet in our solar system to find/see in next step.

[julianh72 (Julian)]

Because the planets move around the Sun, it really changes day-to-day, week-to-week, and year-to-year - and also, what time of the night you are viewing, and where you are viewing from.

Right now (May 2014, southern hemisphere), ignoring the Sun and Moon (which are both pretty obvious when they are up!):

Jupiter is the brightest object in the early evening; look for it in the north-west sky, but it sets around 8:30 pm (and it sets a little earlier each successive day) so you have missed the best chance to view it. However, as it is the largest object in the Solar System (and currently, the biggest "apparent size" as seen from Earth), it still looks pretty spectacular if you set up your telescope early enough to catch a look. (Current magnitude: -1.9, current apparent size: 33.6")

Mars is the brightest object overhead through the evening, so is an easy find (look for a bright red "star", more or less overhead and to the North), but it is relatively small, so you may not see much "Wow" detail unless you can get a fair bit of magnification. (Current magnitude: -0.7, current apparent size: 12.8", or about 1/3 the apparent size of Jupiter when viewed through a telescope)

Saturn is a moderately bright yellowish "star" in the eastern sky in the evening - but it has the biggest instant "Wow!" factor of all the night-sky objects currently visible. (Current magnitude: +0.1, current apparent size: 18.6", not including the spectacular ring system)

Venus is the brightest planet of all right now, but you need to get up in the pre-dawn to see it (rises at about 3:30 am, and sets at about 3:00 pm) (Current magnitude: -4.0, much brighter than Jupiter or Mars at present, current apparent size: 14.8")

Mercury is pretty much a "no show" right now, as it rises at about 8:00 am and sets at about 6:30 pm.

Hope this helps!

[OzStarGazer]

Originally Posted by SingleWord

I watched the Saturn crossed the Moon previous weeks and Saturn was so small (10 inch dob, 20mm ep and 2x barlow). So I want to know which is the easiest planet in our solar system to find/see in next step.

You should be able to see Jupiter's bands as well as the Galilean moons pretty clearly.

[SingleWord]

Originally Posted by julianh72

...
Jupiter is the brightest object in the early evening; look for it in the north-west sky, but it sets around 8:30 pm (and it sets a little earlier each successive day) so you have missed the best chance to view it...

Mars is the brightest object overhead through the evening, so is an easy find (look for a bright red "star", more or less overhead and to the North), but it is relatively small, so you may not see much "Wow" detail unless you can get a fair bit of magnification. (Current magnitude: -0.7, current apparent size: 12.8", or about 1/3 the apparent size of Jupiter when viewed through a telescope)

Hope this helps!

I think I will be watching the planet at about 9pm onward so Jupiter is out of reach.

Yes, I also found few "red" stars looks like Mars (if I don't know the position without looking for at Stellarium).
Looks Mars will be my next watch.

Not sure the other galaxy, eg. Andromeda, Orion nebula.
Can I see the colour or clouds these 2 galaxies by the 10in dob?

[astro744]

Have a look at Alpha Scorpii or Antares which means 'Rival of Mars'.

Mars is the Roman god of war and Ares is the Greek equivalent. Mars and Antares (Anti-Mars) are very similar in colour and sometimes brightness, the latter depending on the distance to Mars.

The Great Orion Nebula (M42) is not a galaxy but a diffuse nebula and is probably one of the easiest and best known non-stellar objects and visible to the unaided eye.

[mental4astro (Alexander)]

In a 10" scope, the only colour you will regularly see is in stars, such as red, yellow, white, and blue (blue as you see in an electric spark).

In nebulae*, colour depends on three factors: 1, how colour blind you are; 2, the age of your eyes; 3, the size of your scope.

In a 10", no matter how young your eyes are or how good your colour rendition is, there is no chance to see colour. That you can get colour in a photograph from a tiny aperture is only due to the time exposure.

Colour would require an aperture starting around 16"/17" if your eyes are young. I saw pale pink and blue in the Orion nebula when I first got my 17.5", some five years ago. Today I can't say I can anymore.

Colour otherwise is only seen in the largest of apertures. I know of one fellow who owns a 40" scope and also with a passion for astro sketching like myself, who routinely sees colour in nebulae, both emission and planetary. But there we are talking about a 1m telescope!

* There are a few exceptions. Planetary nebulae as many of these will display a distinct bluish/green colour. M42 is bright enough that it too can appear bluish/green, here depending on the quality of colour rendition of your eyes. Bright reflection nebula can show blue - I saw a distinct purplely/blue colour in M20 with my 17.5" - most extraordinary as purple is one colour our eyes just don't see at low light levels, but there it was!

Galaxies - no colour. They are just not bright enough. But, with the closest/largest ones, it is possible to distinguish between the stellar continuum and the H2 regions where stars are being formed with the use of nothing more than an OIII filter.

A 10" will begin to show the spiral arm structure of the largest/brightest of the spiral galaxies, such as M31, NGC 1365, and M83 (real tough with this one though). Alas, aperture is KING when it comes to galaxies.

Why no colour? The colour is there - we see it is there because of photos. But our eyes are just not sensitive enough at such low levels of light that we only see things in shades of grey. It is not a fault of the telescope, nor the eyepieces, or any other bit of gear. All to do with having human eyes.

Please don't be too disappointed - photographs give a totally wrong impression about how things actually look like through a telescope. The result being too many people who buy a brand new telescope are quickly 'pissed off' by it as they cannot see objects through it as they appear in the pretty pictures,

[Renato1 (Renato)]

Originally Posted by mental4astro

* There are a few exceptions. Planetary nebulae as many of these will display a distinct bluish/green colour. M42 is bright enough that it too can appear bluish/green, here depending on the quality of colour rendition of your eyes. Bright reflection nebula can show blue - I saw a distinct purplely/blue colour in M20 with my 17.5" - most extraordinary as purple is one colour our eyes just don't see at low light levels, but there it was!

I'm partly colour blind, but is the actual colour in those nebulas aqua green or just plain aqua?

I've noticed checking around the net that some people think Aqua should be considered a colour in its own right, rather than being lumped in with green.

Certainly, to my limited colour vision, whatever that colour is in nebulas, it looks nothing like my lawn grass, but a lot like the "green" I see in some traffic lights.
Cheers,
Renato

[mental4astro (Alexander)]

"Aqua" is a pale blue-green colour. Aqua is one way to describe the colouration that is seen. Colour description is totally a subjective one. Me, I refrain from using the name 'aqua', and describe it a bluish-green, but that is me. Like I said, totally subjective. But as you allude to, colours are certainly not vivid, well, unless you have a 40" scope...

To make matters worse, 1/3 of all males are colour blind to some degree, from bugger all to nearly no colour rendition at all. Females are few who experience any degree of colour blindness.

[SingleWord]

So for a 10 inch dob, what I can see from the "galaxies" eg. M31 will be pale or in white? Other nebulae eg. Orion will be the same.

[Renato1 (Renato)]

Originally Posted by mental4astro

"Aqua" is a pale blue-green colour. Aqua is one way to describe the colouration that is seen. Colour description is totally a subjective one. Me, I refrain from using the name 'aqua', and describe it a bluish-green, but that is me. Like I said, totally subjective. But as you allude to, colours are certainly not vivid, well, unless you have a 40" scope...

To make matters worse, 1/3 of all males are colour blind to some degree, from bugger all to nearly no colour rendition at all. Females are few who experience any degree of colour blindness.

Thanks, yes people may well not know what is meant by Aqua. I often refer to it as the "bluey traffic light green" to others. That aqua or blue green colour does become a tad more obvious at times with a nebula filter on small bright planetarys (unless the filter is adjusting the colour?).

The down side to being colour blind is that we can't fly planes or figure out resistor values or sometimes pocket the brown ball instead of the red ball with some snooker ball sets. The upside is that like Schiaparelli, we actually see what's on Mars, rather than see lots of things that aren't there that normal visioned people saw on Mars. And apparently, during WW11, colour blind Aussies in airplanes had no difficulty spotting Japanese ground camouflage.

The strange thing is that at times, I've shown some people say the Orion nebula through my C8, and they have remarked at the amazing green colours - and all I see is grey.
Cheers,
Renato