Degrees above the Horizon

[Delphine]

Hello, is someone able to provide a picture or pretty good simple general explanation as to what denotes 10 degrees above the horizion and 22 degrees?

I thought when a person stands with their arm outstretched in an angle upwards, that was 10 degrees - did i get that wrong?

[LukeSkywatcher]

I really struggle to estimate angles above the horizon. Obviously i know 45 degrees and 90 degrees.

You could always invest in a Wixey digital angle guage:available from FLO. They make using a Dob much easier when trying to locate objects and finding angles above the horizon.

[Dunkster]

Yeah, clench your first and hold it at arms length with your thumb on top. From top to bottom, that's roughly 10 degrees. For me it works well, with 9 fists more or less going from horizontal to vertical.

I'm no expert on anatomy, but I'd suspect it might vary slightly from person to person depending on individual arm lengths and hand sizes, but still....

[Ibbo!]

A span of your open hand at arms length is about 22 degs and think a fist is about 10 degs thumb nail 1 deg little finger nail about 1/2 deg

Steve

[LukeSkywatcher]

Yeah, clench your first and hold it at arms length with your thumb on top. From top to bottom, that's roughly 10 degrees. For me it works well, with 9 fists more or less going from horizontal to vertical.

I'm no expert on anatomy, but I'd suspect it might vary slightly from person to person depending on individual arm lengths and hand sizes, but still....

I just tried that. It seems pretty accurate within a few degrees (depending on fist size).

Good tip. Thanks for that.

[sologuitarist61]

The main trouble with angles above the horizon is 'where is the horizon?'

Unless you are at sea level (or know where sea level would be taking into account trees, hills, etc.,) it is almost impossible to judge it anyway. 10 degrees above a low hill might in fact be 20 degrees above sea level in reality :icon_scratch:

[LukeSkywatcher]

The main trouble with angles above the horizon is 'where is the horizon?'

Unless you are at sea level (or know where sea level would be taking into account trees, hills, etc.,) it is almost impossible to judge it anyway. 10 degrees above a low hill might in fact be 20 degrees above sea level in reality :icon_scratch:

There is that issue. I consider my horizon to be exactly 90 degrees infront of me even though i am above sea level.

[sologuitarist61]

Depends how flat it is around your way Paul - you may be exactly right in your assumption

[LukeSkywatcher]

I'm on a headland. I know i am a couple of hundred metres above actual sea level. Its downhill to the local beach................so i may be out by a bit.

I tend not to worry too much as Go-To only needs to know where it is in relation to the celestial dome above. Sure it needs a roughly fixed location at ground level also.

TBH..............i'm probably 10-20 degrees above sea level. I really just dont know.

[sologuitarist61]

Sounds good Paul, no light pollution out to sea, so I guess your viewing is good when the weather behaves

[LukeSkywatcher]

Sounds good Paul, no light pollution out to sea, so I guess your viewing is good when the weather behaves

Not great but ok towards the east. I am about a mile inland at my location. It is my best least polluted view.

[coulthamst]

Defining "horizon" is an irrelevance and thinking in terms of height above sea level, when comparing that height with the radius/diameter of the earth and looking into what is as near as makes no difference infinity. "Horizontal" is satisfactory for all practical purposes.

[sologuitarist61]

Never mind at least you have a view and east isn't a bad one as far as I am concerned - away from the sunset and everything rises there first.

[Qualia]

I've jotted in my head the following, they're not that accurate but used with a little 'common sense' should be a helping guide:

With arm held outstretched in an angle upwards:

1º / 1.5º = Width of index finger's tip, that is, from one side of the nail to the other.

With arm outstretched and forming a C shape with thumb and index finger (if you do this with your right hand just reverse the C shape):

3º = From tip of index finger to first joint.

4º = From first joint to second joint (middle section).

6º = From second joint to knuckle.

5º = Distance between Dubhe and Merak.

25º = Distance between Dubhe and Polaris.

10º - 12º = (again, stretch out arm) the width of the back of a hand.

Polaris is seen at your latitude (if you live at 40º lat, then Polaris will be at 40º)

From Polaris + 90º, you arrive at the celestial equator which will be 0º.

Your Zenith will be the mid point directly overhead between Polaris and the celestial equator.

From the celestial equator to the southern horizon will be what remains from 180º. In our case here, from celestial equator (0º) to southern horizon, 50º.

I think this information is correct to my knowledge (it's what I use to find myself about), but please, please correct me if wrong!!

Other than that, hope this helps.

[billinforres]

This works. Just guess where horizontal is and measure away.

It isn't accurate but great for telling someone where an object is if you have a known starting point.