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Tasmania specific bushwalking discussion. Please avoid publishing details of access to sensitive areas with no tracks.Nightskys Jan2015
Sun 04 Jan, 2015 7:32 am
If your out of the tent of a night or two check out the comet aways NNW of Southern cross, between bright Sirius, Lepus and Columbia
http://www.skyandtelescope.com/astronom ... 122920141/
http://www.sydneyobservatory.com.au/wp- ... an2015.pdf
http://www.skyandtelescope.com/astronom ... 122920141/
http://www.sydneyobservatory.com.au/wp- ... an2015.pdf
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- Lovejoy_Schur_12-27-2014.jpg (56.7 KiB) Viewed 3786 times
Re: Nightskys Jan2015
Sun 04 Jan, 2015 9:22 am
Hi greyim,
I was looking at the night sky chart and have a question if I may
regarding the scale or coordinates along the edges.
What does the scale on the left refer to ie. is 0 degrees the horizon?
http://www.skyandtelescope.com/wp-conte ... -550px.gif
Thanks in advance. Neil.
I was looking at the night sky chart and have a question if I may
regarding the scale or coordinates along the edges.
What does the scale on the left refer to ie. is 0 degrees the horizon?
http://www.skyandtelescope.com/wp-conte ... -550px.gif
Thanks in advance. Neil.
Re: Nightskys Jan2015
Sun 04 Jan, 2015 11:49 am
Hi neilmny,
Just like on the earth's surface, the sky has coordinates so that astronomers can locate a particular object. North/south (equivalent to latitude on earth) is known as declination, this is the marking on the y axis. 0 degrees is what you would see in the sky immediately above your head if you are standing on the equator. Negative numbers indicate sky that is overhead further south. e.g. Brisbane is -28 degrees latitude, so the sky at -28 degrees declination will pass directly overhead as seen from Brisbane. Victoria would be further south still. This also means that stars in the far nothern hemisphere can never be seen from here; 90 degrees - 28 = +62 degrees is the most northerly can be seen from Brisbane. If you are in Melbourne, at 38 degrees south, 90 - 38 = +52 degrees north is the most northerly you will be able to see (e.g. the northern horizon will be pretty close to the top of that image). So by the end of January, it's going to be very tough for anyone in Vic or Tas to see the comet anymore.
East/west (equivalent to longitude on earth) is right ascension, this is the marking on the x axis. As the earth rotates, the sky appears to move above us through the right ascension. 1 hour of right ascension is equal to how much the sky appears to move in one hour as seen from anywhere on earth.
Unfortunately this is all very confusing, and can be difficult to equate to your horizon as you have to take into consideration your latitude, the time of day and the time of year. If you are keen to spot the comet, my recommendation would be to try and familiarise yourself with Orion and Taurus (look north - the major stars of both constellations are bright and should be easy to see, even from the city), and use binoculars to try and spot the comet. Bear in mind it will just be a little fuzzy blob, you won't see any bright colours like in the photo! Good luck!
Cheers,
Munch
Just like on the earth's surface, the sky has coordinates so that astronomers can locate a particular object. North/south (equivalent to latitude on earth) is known as declination, this is the marking on the y axis. 0 degrees is what you would see in the sky immediately above your head if you are standing on the equator. Negative numbers indicate sky that is overhead further south. e.g. Brisbane is -28 degrees latitude, so the sky at -28 degrees declination will pass directly overhead as seen from Brisbane. Victoria would be further south still. This also means that stars in the far nothern hemisphere can never be seen from here; 90 degrees - 28 = +62 degrees is the most northerly can be seen from Brisbane. If you are in Melbourne, at 38 degrees south, 90 - 38 = +52 degrees north is the most northerly you will be able to see (e.g. the northern horizon will be pretty close to the top of that image). So by the end of January, it's going to be very tough for anyone in Vic or Tas to see the comet anymore.
East/west (equivalent to longitude on earth) is right ascension, this is the marking on the x axis. As the earth rotates, the sky appears to move above us through the right ascension. 1 hour of right ascension is equal to how much the sky appears to move in one hour as seen from anywhere on earth.
Unfortunately this is all very confusing, and can be difficult to equate to your horizon as you have to take into consideration your latitude, the time of day and the time of year. If you are keen to spot the comet, my recommendation would be to try and familiarise yourself with Orion and Taurus (look north - the major stars of both constellations are bright and should be easy to see, even from the city), and use binoculars to try and spot the comet. Bear in mind it will just be a little fuzzy blob, you won't see any bright colours like in the photo! Good luck!
Cheers,
Munch
Re: Nightskys Jan2015
Sun 04 Jan, 2015 9:17 pm
Thanks Munch, that helps a lot.
Re: Nightskys Jan2015
Wed 07 Jan, 2015 8:43 pm
Hi greyim.. Steve here. Soon to be relocating to Tasmania. (A.S.V. member for 28 years). I recently had a crack at Lovejoy from my backyard at Doreen, Vic, but no luck yet. It's either "Astronomical Event Cloud", or a full moon, or both! Tried dredging my way through the haze with 15 X 60's, but to no avail. Spot on the location, but too hard to penetrate the gunk. lol. Oh well.. My motto for Astronomy is as for the SAS.... "Who Dares Wins!" Maybe when the 40 deg temps and driving rain have passed, Lovejoy will grace us with a nice mag 4 fuzzball!
Cheers.. Steve.
Cheers.. Steve.
Re: Nightskys Jan2015 moonshine
Thu 08 Jan, 2015 5:04 pm
Yes.. well... maybe next week !
Re: Nightskys Jan2015
Thu 08 Jan, 2015 7:38 pm
I spotted Comet Lovejoy last night in Sydney - with all the light pollution and the full moon. It was easily visible with binoculars - once your eyes were dark adapted, and you had to know roughly where to look. It is perhaps easier to spot with a camera - take a few long exposures with a wide angle lens - and look for the green fuzzy blob. It is very easy to locate Orion - and then Rigel and then look a bit to the left. Here is one of my photos -
Taken at 200 mm, 2 seconds, f4 at 16000 ISO (I used a 50 mm f 1.8 lens first to make sure I had the right area of sky). Photos when downloaded show an awful lot of sky fog - but if you shoot in raw, then you can post process to fix things up.
Dave
Taken at 200 mm, 2 seconds, f4 at 16000 ISO (I used a 50 mm f 1.8 lens first to make sure I had the right area of sky). Photos when downloaded show an awful lot of sky fog - but if you shoot in raw, then you can post process to fix things up.
Dave
Re: Nightskys Jan2015
Thu 08 Jan, 2015 10:10 pm
Nice shot Dave. Yeah, it's hard isn't it.. trying to ensure the object is in the field of view. But that pic shows nice fuzz. And the colour is good too. Reminds me of Hyakutake years ago.. 1996 I think? There must be some nice volatile compounds in that snowball. With a bit of luck, we may even get a nice straight, blue ion tail as well. Here's hoping. Cheers... Steve.
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