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Old 02-02-2013, 12:48 AM
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NEO 2012 DA14 visibility from Australia

Near Earth Asteroid 2012 DA14 will be visible from Australia dring its record breaking close approach on February 16 in the early morning, WA fares best, with the brightest and fastest part of the orbit occurring after astronomical twilight for the central and eastern states.

I have a map and links to Heavens Above, where you can generate local maps here

http://astroblogger.blogspot.com.au/...2012-da14.html
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Old 02-02-2013, 04:43 AM
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How do I generate a chart from heavens Above. I can't work out how
to do it for 2012 DA14
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Old 02-02-2013, 10:38 AM
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http://www.iceinspace.com.au/forum/s...d.php?t=101542

Have a look over this thread: there is plenty of help in there to make sure you find it.
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Old 02-02-2013, 12:00 PM
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Quote:
Originally Posted by Analog6 View Post
How do I generate a chart from heavens Above. I can't work out how to do it for 2012 DA14
Odille, have you defined your location in HA? When I logged on it immediately offered to draw a chart for me.

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Asteroid 2012 DA14 flyby
On February 15th/16th the asteroid 2012 DA14 will fly past the Earth at a distance of only 34000 km (inside the ring of geostationary satellites). At a maximum magnitude of about 7.4 it will not be visible to the naked eye, but should be visible through binoculars if you know where to look and live in the right part of the world. Click here for a sky chart and table of positions for your location.
The east coast only gets a couple of hours before twilight, starting around 02:00
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Old 03-02-2013, 09:53 AM
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OzEclipse (Joe Cali)
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A challenging observation

This will be a challenging observation from the east coast for an experienced observer. Early in the evening, it's apparent motion will be slow but it will be quite faint mag 14 Mag 14 is difficult in an 8 inch and easy in a 16inch scope analogous to observing Jupiter.

At dawn it will mag 9, easier in smaller scopes but moving very fast so that it moves through a typical wide angle telescope field (1 deg) every 2 minutes. You need to get ahead of it and wait for it whether you have goto or not. I won't cover advanced equipment that can track objects like this, those owners obviously don't need any advice.

At dawn with a basic GOTO scope, by the time you enter current coords and slew, the asteroid will be out of field. You'll need to slew ahead of the object and wait for it to come into field. Use the same approach if you don't have goto, find a star near the path and wait for the asteroid to pass through the field.

Planetarium programs are not producing accurate finder charts because most of these planetarium programs use a geocentric (centre of the Earth) reference point.

The object will be as close as 3.5 Earth radii. When a close object is overhead the geocentric view and the local view coincide but when the object is near the horizon, you are approaching being 6400km off the line of sight that a planetarium program uses. In the extreme, that can lead to a 15 degree error in plotted position if calculated correctly.

Parallax also leads to a difference in apparent position of about 1 degree between Brisbane and Sydney at 18:00UT so it is important that you don't use any finder chart but one accurately generated for your area. The accuracy of the chart depends on the field of view of the scope you will be using. A chart produced for a lat/long 100km from you will be about 0.1 degree out at 18:00UT. Insignificant if using a wide field refractor, more significant if using a large SCT.

No matter where you live, use the NASA horizons tool to generate coordinates for your general location and plot manually onto a star atlas.

http://ssd.jpl.nasa.gov/horizons.cgi#top

The geocentric (centre of the Earth) reference point is a perfectly valid approach for the vast majority of objects and reduces the number of calculations which in turn makes the program run faster.

The object will be as close as 3.5 Earth radii at its closest. When a close object is overhead to the observer, it is on a line between the center of the Earth and the object so the geocentric view and the local view coincide but when the object is away from the zenith, you are off the line of sight that a planetarium program uses. In the extreme, that can lead to an error in plotted position if calculated correctly. In the extreme case of DA 14 near the horizon when at closest approach of 22500km could lead to a 15 degree parallax error.

On the east coast, the asteroid disappears in twilight when it is about 44000km from Earth. At that time it is at an altitude of 60 deg here in Canberra which could lead to a parallax error of 4 degrees. In Perth, the object is observable at closest approach at a similar altitude and therefore could be off by around 8 degrees.

I use the latest version of starry night. It has DA 14 in the object list but the elements are a mile off. It miscalculated the position at 4am on the 16th by a whopping 35 degrees compared to the Horizons ephemeris. That's not parallax, it's something wrong with the elements used.

On the east coast, it's at its brightest (Mv=9) at astronomical twilight just after 18:00UT. At that time, it will be moving 0.5 degrees per minute. Most of this motion is in DEC. The RA apparent motion starts the night at 0.05 deg/min and only increases to about 0.06 at dawn. But DEC starts the night with almost zero drift and ramps up to about 0.5 deg/min at dawn.

None of this will be news to the many experienced observers on this forum but the many beginners should be aware this won't be an easy object to track. Don't blindly trust planetarium programs.

Joe Cali
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Old 03-02-2013, 10:27 AM
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Quote:
Originally Posted by OzEclipse View Post
........Don't blindly trust planetarium programs.

Joe Cali
No argument there Joe. The makers of Starry Night do not include some NEO's in their automatic updates. Instead I went through the process of manually adding the required data to Starry Night V6.3 and the results were way off when compared to the JPL data. Plotting the path of the asteroid on a paper star chart using the JPL data for my location was the solution.

Fingers crossed for clear skies.

Last edited by Shark Bait; 03-02-2013 at 01:02 PM.
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Old 03-02-2013, 02:45 PM
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Quote:
Originally Posted by Shark Bait View Post
No argument there Joe. The makers of Starry Night do not include some NEO's in their automatic updates. Instead I went through the process of manually adding the required data to Starry Night V6.3 and the results were way off when compared to the JPL data. Plotting the path of the asteroid on a paper star chart using the JPL data for my location was the solution.

Fingers crossed for clear skies.
Stu,
I only purchased v6 a week ago using the special $99 pricing deal they have for SN Pro plus 6. Probably means SN v7.0 will be out next week

So I'm running v6.4.3. I updated my objects list a few days ago after installing and DA 14 is in my SN object list but still generates completely wrong coordinates. It's not just parallax shifted but looks like the wrong inclination. I haven't compared the elements but it's obvious the orbital elements are very wrong. Inclination is out by 60 or so degrees.

The path shows DA 14 traveling between a point south of the SMC to a point south of the LMC.

The horizons path has it traveling mostly northwards accelerating during the night with a small and pretty constant eastwards motion.

Joe

Last edited by OzEclipse; 03-02-2013 at 03:01 PM. Reason: typo removed
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Old 03-02-2013, 03:02 PM
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Quote:
Originally Posted by Shark Bait View Post
No argument there Joe. The makers of Starry Night do not include some NEO's in their automatic updates. Instead I went through the process of manually adding the required data to Starry Night V6.3 and the results were way off when compared to the JPL data. Plotting the path of the asteroid on a paper star chart using the JPL data for my location was the solution.

Fingers crossed for clear skies.
Stu,
I only purchased v6 a week ago using the special $99 pricing deal they have for SN Pro plus 6. Probably means SN v7.0 will be out next week

So I'm running v6.4.3. I updated my objects list a few days ago after installing and DA 14 is in my SN object list but still generates completely wrong coordinates. It's not just parallax shifted but looks like the wrong inclination. I haven't compared the elements but it's obvious the orbital elements are very wrong. Inclination is out by 60 or so degrees.

The path shows DA 14 traveling between a point south of the SMC to a point south of the LMC.
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Old 03-02-2013, 03:04 PM
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Quote:
Originally Posted by ian musgrave View Post
Near Earth Asteroid 2012 DA14 will be visible from Australia dring its record breaking close approach on February 16 in the early morning, WA fares best, with the brightest and fastest part of the orbit occurring after astronomical twilight for the central and eastern states.

I have a map and links to Heavens Above, where you can generate local maps here

http://astroblogger.blogspot.com.au/...2012-da14.html
Thanks for the heads up Ian and the link to Heavens Above.
Gove NT will get good visibility & of course I will be on the east coast at that time in Cairns. I will certainly be giving it a go though !
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Old 03-02-2013, 04:06 PM
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Quote:
Originally Posted by OzEclipse View Post
Stu,
I only purchased v6 a week ago using the special $99 pricing deal they have for SN Pro plus 6. Probably means SN v7.0 will be out next week

So I'm running v6.4.3. I updated my objects list a few days ago after installing and DA 14 is in my SN object list but still generates completely wrong coordinates. It's not just parallax shifted but looks like the wrong inclination. I haven't compared the elements but it's obvious the orbital elements are very wrong. Inclination is out by 60 or so degrees.

The path shows DA 14 traveling between a point south of the SMC to a point south of the LMC.

The horizons path has it traveling mostly northwards accelerating during the night with a small and pretty constant eastwards motion.

Joe
I have just checked my copy of Starry Night Enthusiast and it is Version 6.4.3 as well. Since I last looked, Simulation Curriculum have released an automatic update that includes Asteroid 2012 DA14. Their orbital path almost matches the data that I manually added to the new asteroid objects but it is still a long way off when compared to the JPL data. Obviously, I will be using the JPL data for my location that I plotted onto the paper star charts.

To be fair, I am surprised that they added Asteroid 2012 DA14 to their updates. This is what they have to say about NEO's on their online help site:

Starry Night's asteroid data file (the Asteroids.txt file in your Sky Data folder# contains a selection of interesting objects. There are far more such objects available than we include in Starry Night; if we included the hundreds of thousands of known asteroids, the average home computer would not be able to run the simulation. In addition, the orbital data for some near-Earth asteroids #NEOs) are changing so quickly that we do not include them, in the interests of accuracy.

The rest of SN's help information for NEO's can be found at this link:
https://support.simulationcurriculum...n-starry-night
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Old 03-02-2013, 07:09 PM
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As the orbital data from JPL has been updated I went back to check the hourly markers on my paper star charts for Asteroid 2012 DA14. There are small alterations to the hourly positions but the path traced by the asteroid as it moves across the sky has not really shifted.

As an example of how far Starry Night is missing by (for my location), at 4am EST on the 16th Feb:

JPL's data has the asteroid passing through Eta Carinae Nebula

SN v6.4.3 shows the asteroid passing through Mensa heading towards the LMC.

This means that at 4am, SN is off the predicted path by approx 27 degrees.
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Old 03-02-2013, 07:45 PM
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Hi,

You better use geocentric orbital data for this asteroid. Heliocentric orbit is no good for this. Read Bill Gray post how he do that in own software GUIDE
http://tech.groups.yahoo.com/group/g...r/message/9270
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Old 03-02-2013, 10:09 PM
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Hi,

You better use geocentric orbital data for this asteroid. Heliocentric orbit is no good for this. Read Bill Gray post how he do that in own software GUIDE
http://tech.groups.yahoo.com/group/g...r/message/9270
Thanks Limax,

I have had a quick look at the site in your link. I will have to study it in more detail before I can make use of the information on offer.
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Old 03-02-2013, 11:12 PM
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Quote:
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Stu,
I only purchased v6 a week ago using the special $99 pricing deal they have for SN Pro plus 6. Probably means SN v7.0 will be out next week
Joe, where did you get that price? I can't see any specials on http://store.simulationcurriculum.com
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Old 04-02-2013, 10:16 AM
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"Netwolf" published a discount code in the software thread that you type in at checkout.
http://www.iceinspace.com.au/forum/s...d.php?t=102580

Code : The promo code is: pplusjan2013

When you type in the code during checkout, the price drops from $249 to $99. Unfortunately, the discount was for January only however I suggest you try it today and see because the USA February business month doesn't start until tonight. Others in the thread reported being able to use the code over the weekend.

Joe
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Old 10-02-2013, 07:54 AM
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Some interesting media (on ABC news at least) about this upcoming approach and even catching on in social media (I just saw a post from Jon Stewart, from the daily show). Given the Science article this week adding more evidence to the dinosaur impact extinction hypothesis, this might be a great opportunity for astronomy popularization at the local level.
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Old 14-02-2013, 05:01 PM
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Just spotted your article on the asteroid for ABC Science, Ian!
Loved it and so well explained.
And the scale you explained with the ball and the sesame seed was great fun to read and picture in my head.
Quote:
West is best
Your view of this asteroid depends on the state you are in. People in Western Australia have the best view seeing nearly the entire asteroid flyby.
There the asteroid becomes bright enough to see in binoculars around 2:30 am local time. Naturally, the amount of local light pollution is important; people in the countryside with dark skies will be able to see the asteroid earlier and easier than those in light polluted suburbs.
The central states have the next best views, with the brightest part of the pass occurring around astronomical twilight, when the skies are still quite dark (an hour and a half before sunrise, Darwin sees it before astronomical twilight at around 4:30 am local time Adelaide after at around 5:30 am).
The eastern states don't do as well. Brisbane, Sydney and Hobart have the brightest part of the pass deep in the twilight. Melbourne and inland sites such as Canberra see a little bit of the pass before it disappears in the twilight.
Lots more info here, Ian gives the locations and approx. times where it'll be bright enough.
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Old 14-02-2013, 09:46 PM
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Had a look at HA and the data it gave for our location,if I type in the coordinates of the 5 am position and start taking a few photos,would that be best?

I have a Vixen Sky Sensor 2000pc and I think it can be give comet data and track it,not sure if an astriod would be similar-and its been a while since I have used it,but looking at giving it ago.

not sure where to find a sky view map,I did see the link given which showed one for S.A area-certainly be handy if there was a S.E QLD one somewhere.
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Old 14-02-2013, 11:10 PM
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Quote:
Originally Posted by hotspur View Post
Had a look at HA and the data it gave for our location,if I type in the coordinates of the 5 am position and start taking a few photos,would that be best?

I have a Vixen Sky Sensor 2000pc and I think it can be give comet data and track it,not sure if an astriod would be similar-and its been a while since I have used it,but looking at giving it ago.

not sure where to find a sky view map,I did see the link given which showed one for S.A area-certainly be handy if there was a S.E QLD one somewhere.
5am is daylight Chris, So you would see nothing.
find your coordinates from here then find it visually.
http://ssd.jpl.nasa.gov/horizons.cgi#results
Best view for SEQ will be about 03:30 before it starts getting light.
The asteroid will still be only mag 9.7, so quite faint really,but should be
alright for imaging.
Cheers
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Old 15-02-2013, 07:21 AM
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5am is daylight Chris, So you would see nothing.
Here in Melbourne, Astronomical Dawn is at 5:11AM. Obviously, it's a close call, but I think people who view in the 3AM to 5AM should have a reasonable chance as DA14 approaches earth for its closest pass.

Of course location changes everything. But, even in Brisbane, it's 5:09AM, so I think it's still reasonable to have 5AM be the end of the viewing window. No?
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