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Wednesday, April 22, 2015

 

Geomagnetic Alert (22 April, 2015)

A geomagnetic alert has been issued by the Australian IPS for the 22nd (yes tonight) to possibly the morning of the 23rd due to a high speed solar wind stream from a coronal hole. Geomagnetic activity is rated at "Unsettled to Active, isolated minor storm periods possible." Aurora, if they occur, are likely to be seen only in Tasmania (possibly Victoria if the minor storm eventuates)

Aurora can occur at any time after nightfall (although around midnight or just after seems to be common). Dark sky sites have the best chance of seeing anything, and always allow around 5 minutes for your eyes to become dark adapted.
As always look to the south for shifting red/green glows, beams have been reported consistently over the last few aurora and a large green "blob" has been seen.

The all sky aurora camera in Southern Tasmania at Cressy may be helpful.
<http://www.ips.gov.au/Geophysical/4/2>

SUBJ: IPS GEOMAGNETIC DISTURBANCE WARNING 15/14
ISSUED AT 2339UT/21 APRIL 2015
BY THE AUSTRALIAN SPACE FORECAST CENTRE.

Due to continued effect of a high speed solar wind stream from
a coronal hole, isolated periods of minor geomagnetic storm may
be observed on 22 April.

INCREASED GEOMAGNETIC ACTIVITY EXPECTED
DUE TO CORONAL HOLE HIGH SPEED WIND STREAM
FOR 22 APRIL 2015
_____________________________________________________________

GEOMAGNETIC ACTIVITY FORECAST
22 Apr:  Unsettled to Active, isolated minor storm periods possible

Further monitoring at
http://www.ips.gov.au

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The 2015 Australian Lyrid Meteor Shower, Morning 23 April

The morning sky looking north as seen from Brisbane at 5:00 am AEST on April 23. The Lyrid radiant is marked with a yellow cross. Similar views will be seen elsewhere at an equivalent local time. The radiant will be higher in northern Australia, and lower in southern Australia (click to embiggen). 

The Lyrids, the debris of comet C/1861 G1 (Thatcher) are a weak but reliable shower that occurs every year between April 16- April 25, with the peak this year around 24 hrs UT on April 22 .

That's  around 10 am 23 April in east coast Australia, the radiant doesn't rise until 1 am on the 23rd, so the best time to view the Lyrids in Australia is from 4 am on the 23rd. 

The predicted ZHR this year is 18 meteors per hour. This means that under ideal conditions, you will see a meteor on average about once every three minutes. This can be as interesting as watching paint dry. Also, while that meteor every three minutes is the average, meteors are like buses, you wait for ages and then a whole bunch turn up. In Australia, the rate is even less, around 4-5 meteors an hour in Northern Australia. For southern Australia, the rate is even lower.

The predicted ZHR this year is 18 meteors per hour. This means that under ideal conditions, you will see a meteor on average about once every three minutes. This can be as interesting as watching paint dry. Also, while that meteor every three minutes is the average, meteors are like buses, you wait for ages and then a whole bunch turn up.
 
The rate is actually less than the ZHR, ZHR means Zenithal Hourly Rate, the number of meteors you could expect to see if the radiant (the apparent position where the meteors originate) was at the highest point of the sky, under dark sky conditions.

Of course under real conditions the Lyrids radiant will not rise that high for most places, and most places won't have really dark skies. The lower the radiant is, the thicker atmosphere will obscure the fainter meteors, and some of the meteors will start to "burn" below the horizon, so over all you will see fewer.

This is particularly true in Australia, where the radiant is very low to the horizon. In Australia the radiant rises about 1 am local time, but it is not really high enough for there to be any real chance of seeing meteors until around 4 am, when the radiant is between three handspans to four handspans above the horizon (see diagram above). The Moon has long set, so Moonlight is not a factor this year..

From Australia, at 4 am, under dark sky conditions, we will see between 3 meteors per hour (southern states) to 4-5 meteors per hour (Northern Territory and QLD).


 If you want to see what the rates will be like at your area, try the Meteor Flux Estimator. The illustration shows the output for dark sky sites in Brisbane.

Choose 6 April Lyrids from the drop down meteor shower Menu, the date (make sure that you set the year to 2015, and your location, most people will have to put in their latitude and longitude (strangely, Adelaide, Brisbane, Darwin and Perth are listed in the drop down menu, but Sydney, Melbourne and Hobart are not) under "other" in the location box.

This will give you a chart of the numbers of meteors per hour you can expect at various times (see image to the left).

The Lyrids are pretty poor in Australia, but if you are patient you may see the occasional meteor shooting up from below the horizon.

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Venus, Moon and Aldebaran, April 21 2015

Venus, the Moon and the Hyades on 21 April 2015. Orion is visible above them. Stack of 10x10 second exposures 400 ISO with my Canon IXUS. Click to embiggen to see both the Moon and Venus reflected in the sea..Venus, the Moon, Aldebaran (the brightest star) and the Hyades on 21 April 2015. Stack of 10x8 second exposures 400 ISO and 3 x Zoom with my Canon IXUS. Click to embiggen.

After days of terrible weather and inconvenient cloud, the sky was perfectly clear and I could see Venus and the crescent Moon clearly on the train on the way home. Got the camera set up at home and then watched the Moon and stars brighten as the twilight deepened and the Moon and Venus headed to the sea.


 Venus and the Moon (and Aldebaran if you click to embiggen) above the roof at around 6:00 pm.

Tomorrow  (22 April) the crescent Moon will be on the other side of Venus and Aldebaran. Lets hope its is clear as well. You should be able to see Venus in daylight by looking down from the Moon.

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Tuesday, April 21, 2015

 

The Sky This Week - Thursday April 23 to Thursday April 30

This is Global Astronomy Month. The First Quarter Moon is Sunday April 26. Venus is prominent in the twilight evening sky. Mars is lost in the twilight. Jupiter is the brightest object in the evening sky once Venus has set. The Moon visits Jupiter on the 26th. Saturn is in the head of the Scorpion and now visible in the evening. Mercury is lost to view. Lyrid Meteor shower morning 23rd.

The First Quarter Moon is Sunday April 26. The Moon is at apogee, when it is furthest from Earth, on the 29th.

Evening sky on  Saturday April 21 looking west as seen from Adelaide at 18:30 (6:30 pm) ACST in South Australia.  Venus is obvious in the early evening sky in line with the bright star Aldebaran. Similar views will be seen elsewhere at the equivalent local time (click to embiggen).

Venus is easy to see above the western horizon in the twilight. At nautical twilight, an hour after sunset, it is around two hand-spans above the horizon, and still visible at astronomical twilight.

During the week Venus heads away from the Hyades cluster and Aldebaran towards the stars Castor and Pollux, heading for a meeting with Jupiter later next month..

Mars  is lost in the twilight.

Evening sky on Sunday April 26 looking north-west as seen from Adelaide at 20:00 ACST showing Jupiter and the Moon.  The inset shows Jupiter's Moons at this time. Jupiter is the brightest object above the north-western horizon once Venus has set. (click to embiggen).

 Jupiter  is easily seen  in the evening sky. It is the brightest object above the northern horizon when twilight ends, and continues into the north-western sky as the night goes on. It is between the bright star Regulus in the sickle of Leo (this forms the head of the constellation of the  Lion) and Pollux in Cancer. It is also not far from the rather nice Beehive cluster in Cancer, and looks very good in binoculars.

Jupiter was  at opposition, when it is biggest and brightest in our sky, on 7 February, but it will be an excellent object for many weeks to come.  Jupiter is visible for most of the night, setting just after midnight, and is high enough for telescopic observation once twilight is over. Jupiter's Moons will be putting on a good display in both binoculars and small telescopes.

Evening sky on Saturday April 25 looking east as seen from Adelaide at 22:00 ACST.  Saturn is now easily visible above the horizon. The inset shows the telescopic view of Saturn at this time. (click to embiggen).

Saturn is now easily visible around 9 pm near the head of the constellation of the Scorpion not far from the bright red star Antares. The sight of the distinctive constellation of the Scorpion curled above the horizon, with bright Saturn in its head, is very nice indeed.

While Saturn is  readily visible from around 21:00, it is best for telescope observation from around 22:00 into the morning hours.

Mercury is low in the western evening sky, but is difficult to see in the twilight.

The morning sky looking north as seen from Brisbane at 5:00 am AEST on April 23. The Lyrid radiant is marked with a yellow cross. Similar views will be seen elsewhere at an equivalent local time the radiant will be higher in northern Australia, and lower in southern Australia (click to embiggen). 

The Lyrids, the debris of comet C/1861 G1 (Thatcher) are a weak but reliable shower that occurs every year between April 16- April 25, with the peak this year around 24 hrs UT on April 22 .

That's  around 10 am 23 April in east coast Australia, but as the radiant doesn't rise until 1 am, the best time to view the Lyrids in Australia is from 4 am on the 23rd. 

The predicted ZHR this year is 18 meteors per hour. This means that under ideal conditions, you will see a meteor on average about once every three minutes. This can be as interesting as watching paint dry. Also, while that meteor every three minutes is the average, meteors are like buses, you wait for ages and then a whole bunch turn up. In Australia, the rate is even less, around 6 meteors an hour in Northern Australia. For southern Australia, the rate is even lower.


This is Global Astronomy Month. See the Astronomers Without Borders site for a rundown of what's on. 
 
There are lots of interesting things in the sky to view with a telescope. Especially with Jupiter just past opposition and Saturn rising. If you don't have a telescope, now is a good time to visit one of your local astronomical societies open nights or the local planetariums.

Printable PDF maps of the Eastern sky at 10 pm AEST, Western sky at 10 pm AEDST. For further details and more information on what's up in the sky, see Southern Skywatch.

Cloud cover predictions can be found at SkippySky

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Friday, April 17, 2015

 

Aurora Watch (17-18 April)

An Aurora Watch and a geomagnetic alert has been issued by the Australian IPS for the 17th (yes tonight) to the 18th due to a high speed solar wind stream from a coronal hole. Given long lasting effects for the unexpected aurora on the 15th (which lasted into the morning of the 16th) and the bursts of geomagnetic activity that occurred during daylight hours today this could translate into aurora at any time. Geomagnetic activity is rated at "unsettled to active with isolated Minor Storm levels." Aurora, if they occur, are likely to be seen only in Tasmania (possibly Victoria if the minor storm eventuates), but in the last unexpected storm they were seen in WA as well.

Aurora can occur at any time after nightfall (although around midnight or just after seems to be common). Dark sky sites have the best chance of seeing anything, and always allow around 5 minutes for your eyes to become dark adapted.

As always look to the south for shifting red/green glows, beams have been reported consistently over the last few aurora and a large green "blob" has been seen.

The all sky aurora camera in Southern Tasmania at Cressy may be helpful.
<http://www.ips.gov.au/Geophysical/4/2>

GEOMAGNETIC ACTIVITY FORECAST
17 Apr:  Mostly unsettled to active with minor storm periods possible at high
latitudes

SUBJ: IPS AURORA WATCH
ISSUED AT 0713 UT ON 17 Apr 2015 BY IPS RADIO AND SPACE SERVICES
FROM THE AUSTRALIAN SPACE FORECAST CENTRE

A coronal hole solar wind stream has resulted in more significant and
sustained geomagnetic activity than anticipated during the past 24-48
hours with auroras observed in far southern Australian regions, eg
Tasmania. Should this activity continue further auroras may be
observed over these and other mid-high latitude regions tonight.
Aurora alerts will follow should favourable space weather activity
eventuate.


Further monitoring at
http://www.ips.gov.au

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My First Image of C/2015 G2 (MASTER) 15 April 2015

New comet C/2015 G2 MASTER, currently around magnitude 9 in the early morning sky. Imaged with iTelescope T9. A median stack of 3x180 second luminance exposures. Click to embiggen.

Nice long thin tail.

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Venus and the Hyades

Venus and the Hyades on 12 April 2015. The Pleiades are hidden by cloud. Stack of 10x15 second exposures 400 ISO with my Canon IXUS. Click to embiggen.Venus and the Hyades on 15 April 2015. The Pleiades are still hidden by cloud. Stack of 10x15 second exposures 400 ISO with my Canon IXUS. Click to embiggen.

Venus and the Pleiades had a close encounter over the weekend, I of course, had cloud. I did get some clear patches, enough that I got some shots though. None with the Pleiades in them though.

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Wednesday, April 15, 2015

 

Aurora Happening NOW! (11:28 PM 15 April)

Unaided eye aurora are being reported from Tasmania NOW, despite cloud. Kindex is 4, Bz North but impressive glows and beams are being reported. Go out and look NOW!

EDIT: Current reports Park Beach,  Old Beach, Howden (now clouded out), Murdunna  and Esperance WA!

Dark sky sites have the best chance of seeing anything, and always allow around 5 minutes for your eyes to become dark adapted.
As always look to the south for shifting red/green glows.


The all sky aurora camera in Southern Tasmania at Cressy may be helpful, beams are being picked up on it at the moment,
<http://www.ips.gov.au/Geophysical/4/2>

Further monitoring at
http://www.ips.gov.au

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Tuesday, April 14, 2015

 

The Sky This Week - Thursday April 16 to Thursday April 23

This is Global Astronomy Month. The New Moon is Sunday April 19. Venus is prominent in the twilight evening sky. The crescent Moon, Venus and the red star Aldebaran form a triangle in the evening sky. Mars is lost in the twilight. Jupiter is the brightest object in the evening sky once Venus has set. Saturn is in the head of the Scorpion and now visible in the evening. Mercury is lost to view.

The New Moon is Sunday April 19.

Evening sky on Tuesday April 21 looking west as seen from Adelaide at 18:30 (6:30 pm) ACST in South Australia.  Venus is obvious in the early evening sky and forms a triangle with the crescent Moon and the bright star Aldebaran. Similar views will be seen elsewhere at the equivalent local time (click to embiggen).

Venus is easy to see above the western horizon in the twilight. At nautical twilight, an hour after sunset, it is around two hand-spans above the horizon, and still visible at astronomical twilight.

During the week Venus heads towards the Hyades cluster and Aldebaran. Venus and Aldebaran are closest on the 19th. On the 21st and the 22nd the pair are joined by the crescent Moon, making an attractive triangle on these nights. The 21st is not quite the "Night of the Smiley Fritz" but will still look rather anthropomorphic.

Mars  is lost in the twilight.

Evening sky on Saturday April 18 looking north-west as seen from Adelaide at 22:00 ACST showing Jupiter.  The inset shows Jupiter's Moons at this time. Ganymede is about to come out from behind Jupiter at this time. Jupiter is the brightest object above the north-western horizon once Venus has set. (click to embiggen).

 Jupiter  is easily seen  in the evening sky. It is the brightest object above the northern horizon when twilight ends, and continues into the north-western sky as the night goes on. It is between the bright star Regulus in the sickle of Leo (this forms the head of the constellation of the  Lion) and Pollux in Cancer. It is also not far from the rather nice Beehive cluster in Cancer, and looks very good in binoculars.

Jupiter was  at opposition, when it is biggest and brightest in our sky, on 7 February, but it will be an excellent object for many weeks to come.  Jupiter is visible for most of the night, setting around 1 am, and is high enough for telescopic observation once twilight is over. Jupiter's Moons will be putting on a good display in both binoculars and small telescopes.

Evening sky on Saturday April 18 looking east as seen from Adelaide at 22:00 ACST.  Saturn is now easily visible above the horizon. The inset shows the telescopic view of Saturn at this time. (click to embiggen).

Saturn is now easily visible around 10pm near the head of the constellation of the Scorpion not far from the bright red star Antares. The sight of the distinctive constellation of the Scorpion curled above the horizon, with bright Saturn in its head, is very nice indeed.

While Saturn is  readily visible from around 22:00, it is best for telescope observation from around 23:00 into the morning hours.

Mercury re-enters the western evening sky, but is lost in the twilight.

This is Global Astronomy Month. See the Astronomers Without Borders site for a rundown of what's on. 
 
There are lots of interesting things in the sky to view with a telescope. Especially with Jupiter just past opposition and Saturn rising. If you don't have a telescope, now is a good time to visit one of your local astronomical societies open nights or the local planetariums.

Printable PDF maps of the Eastern sky at 10 pm AEST, Western sky at 10 pm AEDST. For further details and more information on what's up in the sky, see Southern Skywatch.

Cloud cover predictions can be found at SkippySky

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Saturday, April 11, 2015

 

Aurora Alert NOW (11 April)

An aurora alert has been issued by the Australian IPS for high latitudes, some reports of green glows from Tasmania, and a report of aurora from Dunedin NZ

Dark sky sites have the best chance of seeing anything, and always allow around 5 minutes for your eyes to become dark adapted.
As always look to the south for shifting red/green glows, beams have been reported too.

The waning Moon will interfere quite a bit after it rises around 10:00 pm.

The all sky aurora camera in Southern Tasmania at Cressy may be helpful, but has been on the blink lately,
<http://www.ips.gov.au/Geophysical/4/2>

SUBJ: IPS AURORA ALERT HIGH LATITUDES
ISSUED AT 0920 UT ON 11 Apr 2015 BY IPS RADIO AND SPACE SERVICES
FROM THE AUSTRALIAN SPACE FORECAST CENTRE

Further monitoring at
http://www.ips.gov.au

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Two Bright Planets, Two Clusters (11 April, 2015)

Evening sky on Saturday April 11 looking west as seen from Adelaide at 19:00 (7:00 pm) ACST in South Australia.  Venus is obvious in the early evening sky and is close to the Pleiades. Similar views will be seen elsewhere at the equivalent local time (click to embiggen).Evening sky on Saturday April 11 looking north-west as seen from Adelaide at 22:00 ACST showing Jupiter.  The right inset shows Jupiter's Moons at this time.The Left inset shows the Beehive cluster. Jupiter is the brightest object above the north-western horizon once Venus has set. (click to embiggen).

This weekend, ifwe are not clouded out, there will be a rather nice conjunction of bright plantes and star clusters.

On Saturday 11 April, Venus is at its closest to the beautiful Pleiades cluster. Venus has been edging closer to this iconic open cluster for some days now, and will be close for a few more after Saturday, but Saturday is when it is at its best. Even under suburban skies the cluster is easily visible to the unaided eye, and will look neat with Venus nearby in binoculars.

Venus is visible from around Sunset, but the Pleiades and Venus will be best around an hour after Sunset. This is a balance between the darkness of the sky and the height above the horizon (the Pleaides will be around a hand-span above the western-horizon at this time.

Over to the north-west is Jupiter, the brightest object in the sky after Venus, it is close to another iconic open cluster, the Beehive. The Beehive is fainter and less obvious than the Pleiades, and may be difficut to see with the unaided eye in suburban settings, but Jupiter and the Beehive will look good in binocuars together.

Unlike Venus and the Pleiades, Jupiter stays within binocular range of the Beehive for a couple of weeks.

So this weekend is a great time to see a rather unusual and beautiful sights, tow bright planets near two iconic (mostly) unaided eye visible open clusters.


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Friday, April 10, 2015

 

Geomagnetic storm happening NOW (10 April)

Hobart
 K-Index plot diagramThe coronal mass ejection hit in daylight, but a class 2 geomagnetic is still going on. At the moment the Kp is 4 Australia wide and 5 in Hobart. However the Bz is North, so this may not produce significant aurora.

Camera only colour has been reported in Tasmania.

However, the best thing is to keep on looking, while there is camera only colour, something stronger may occur, and if the polarity switches south then serious aurora should happen, possibly as far north as Victoria. Cloud is hampering reports from Tasmania, but it is well worthwhile popping out a regular intervals to check.

Dark sky sites have the best chance of seeing anything, and always allow around 5 minutes for your eyes to become dark adapted.
As always look to the south for shifting red/green glows, beams have been reported too.

The waning Moon will interfere quite a bit after it rises around 9:30 pm.

The all sky aurora camera in Southern Tasmania at Cressy may be helpful, but has been on the blink lately,
<http://www.ips.gov.au/Geophysical/4/2>http://www.ips.gov.au/Geophysical/4/2Further monitoring at
http://www.ips.gov.au

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