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Wednesday, October 18, 2017

 

Orionid Meteor Shower, Morning 21-23 October 2017

Morning sky as seen from Adelaide facing north-east at 4:00 am ACDST on 22 October, the Orionid radiant is indicated with a starburst. Similar views will be seen elsewhere in Australia at an equivalent local time. Click to embiggen.

The Orionids are a worthwhile shower that somewhat favours the Southern Hemisphere,best seen between 2-5 am, the radiant, the point where meteors appear to originate from, being just under Betelgueuse, the bright red star in Orion.

If you draw an imaginary line between Procyon and Aldebaran, then drop another imaginary line from Betelgeuse to the horizon, the radiant is just next to the intersection of those two lines.

The Orionids are the debris from Halley's comet. The Orionids maximum is on October 21 UT (October 22 Australian time).


This year the sky is nicely dark for the shower.

The best viewing is the morning of the 22nd, when between 3-5 am under dark skies you should see about a meteor every 3-4 minutes, although reasonable rates will be seen the mornings before and after (see table below).

You can find out the predicted rates for your location using the NASA meteor flux estimator (use 8 Orionids and make sure you set the dates to 21-22 October 2017). 
Unfortunately, both Chrome and Firefox have changed their security settings to prevent plugins from running, and the flux estimator only runs under Internet Explorer now.
You can follow the progress of the shower at the IMO Orionids live page.

If you decide to get up, allow at least 5 minutes for your eyes to adjust, and be patient, it may be several minutes before you are rewarded with you first meteor, then a couple will come along in quick succession.

Choose a viewing spot where you can see a large swathe of sky without trees or buildings getting in the way, or with street-lights getting in your eyes. The darker the spot the better (but do be sensible, don't choose a spot in an unsalubrious park for example). Look to the north-east, and the distinctive red star Betelgeuse below the saucepan will be easy to spot. The meteors should originate just below here. However, let your eyes roam a bit to pick up meteors that begin their "burn" a fair distance from the radiant.

A lawn chair or something similar will make your observing comfortable (or a picnic rug spread on the ground and a nice pillow), and having a Thermos of hot coffee, tea or chocolate to swig while watching will increase your comfort. (Here's some hints on dark adaption of your eyes so you can see meteors better).

The following table show the predicted peak rates at around 5 am local time on the mornings of the 21st, 22nd and 23rd of October for a number of cities under dark sky conditions. Rates will be similar at the same latitude as these cities, and rates will be intermediate at spots between these cities.

TownMorning October 21Morning October 22Morning October 23
Adelaide11 meteors/hr15 meteors/hr13 meteors/hr
Brisbane13 meteors/hr17 meteors/hr15 meteors/hr
Darwin16 meteors/hr21 meteors/hr18 meteors/hr
Perth12 meteors/hr16 meteors/hr14 meteors/hr
Melbourne10 meteors/hr14 meteors/hr12 meteors/hr

Here is the near-real time satellite view of the clouds http://satview.bom.gov.au/
Cloud cover predictions can be found at SkippySky.   

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The Sky This Week - Thursday October 19 to Thursday October 26

The New Moon is Friday, October 20. Jupiter is lost in the twilight.  Mercury returns low in the evening twilight, and is near the Moon on the 21st. Saturn is visible most of the evening in the heart of the Milky Way. Saturn is visited by the Moon on the 24th . Venus is now very low in  the morning twilight while Mars rises higher. Orionid meteor shower peaks on the mornings of the 21st and 22nd.

The New Moon is Friday, October 20. The moon is at apogee, when it is furthest from the Earth, on the 25th.

Evening sky on Saturday October 21 looking north-west as seen from Adelaide at 20:01 ACDST  (30 minutes after sunset). Mercury is very low above the horizon in the twilight with the thin crescent Moon nearby.

Similar views will be seen elsewhere in Australia at the equivalent local time (30 minutes after sunset). (click to embiggen).

Mercury is setting in early evening and is above the western horizon in the twilight. You will need a clear level horizon to see it, although by the end of the week it is more prominent. On the 21st the thin crescent Moon is near mercury.

Jupiter is lost in the twilight.

Evening sky on Tuesday October 24 looking west as seen from Adelaide at 21:05 ACDST, 90 minutes after sunset.

The inset shows the telescopic view of Saturn at this time. Similar views will be seen elsewhere in Australia at the equivalent local time. (90 minutes after sunset, click to embiggen).

Saturn was  at opposition on June the 15th, when it was biggest and brightest in the sky as seen from earth. Saturn is visible all evening long. Saturn is a good telescopic target from 9:00 pm daylight saving time until around  9:30 pm daylight saving time. It is poised next to the dark rifts in the Milky Way and is in a good area for binocular hunting. Although still high in the early evening sky, Saturn begins to sink into the western evening skies as the week progresses.  Saturn's rings are visible even in small telescopes and are always good to view. Saturn is close to the crescent Moon on the 24th.

The constellation of Scorpio is a good guide to locating Saturn. The distinctive curl of Scorpio is easy to see above the north-western horizon, locate the bright red star, Antares, and the look to the left of  that and slightly above, the next bright object is Saturn.

Morning sky on  Saturday October 21 looking east as seen from Adelaide at 6:00 ACDST (30 minutes before sunrise). Venus is bright just above the horizon and forms a line with Mars.

 Similar views will be seen throughout Australia at the equivalent local time (that is 30 minutes before sunrise, click to embiggen).

Venus  is lowering in the morning sky. This week Venus forms a line with  Mars. It is becoming much harder to see Venus in the early twilight, and you will need a clear unobstructed horizon to see the pair low in the twilight. 

 Mars is climbing higher the twilight, but sound be reasonably visible this week.



The location of the Orionid meteor radiant (starburst) as seen looking north-east at 3:00 am October 23 local daylight saving time from Adelaide. Similar views will be seen at equivalent local times elsewhere.

The Orionid Meteor shower peaks on October 21  in Australia, the radiant for the Orionids rises around  2 am on October 22, with the best meteor viewing being between 3:00 am and 4:00 am. You can expect to see roughly a meteor every 5 minutes or so under dark skies.

As the name suggest, the meteors will seem to originate just below Orion. Allow several minutes for your eyes to adjust to the darkness and be patent, it may take ages for a meteor to turn up, then you may see a few in a row.

You can use the Meteor Flux Estimator to predict the number of meteors you might see at your location. Choose 8 Orionids, and make sure the date is 2017 and you have DST on if you are in daylight saving zones.

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

Cloud cover predictions can be found at SkippySky.

Here is the near-real time satellite view of the clouds (day and night) http://satview.bom.gov.au/

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Saturday, October 14, 2017

 

Geomagnetic warning and Aurora Watch (14 October)

The SWS has issued a geomagnetic warning and aurora watch for 14 October (UT) due to expected arrival of a solar wind stream from a coronal hole. This is expected to arrive early in the UT day on the 14th (which is the evening of the 14th Australian time).  The SWS predicts active to minor storm conditions. The Space Weather Prediction Service has Predicted a G1 storm on the early evening of 14 October  and there was a minor geomagnetic storm in the daylight hours earlier.

If these geomagnetic events occur and result in aurora they could be seen from Tasmania weather permitting. The Moon is past last quarter and will not significantly interfere with aurora. Be patient, as the activity may rise and fall of the magnetic polarity of the wind may fluctuate significantly.

This event is unlikely to be as spectacular as those in September, but still worth a look.

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, as well as bright proton arcs and "picket fences". A double arc,  blobs, and curtains were seen in Septembers aurora despite the moonlight.

Here is the near-real time satellite view of the clouds http://satview.bom.gov.au/
Cloud cover predictions can be found at SkippySky.  

A new aurora camera is being installed at Campania, Tasmania. A live feed of the images from this camera is  sill not available.

SUBJ: SWS GEOMAGNETIC DISTURBANCE WARNING 17/51
ISSUED AT 2319UT/13 OCTOBER 2017
BY THE AUSTRALIAN SPACE FORECAST CENTRE.

The previous geomagnetic warning is extended for one more day.
The high speed streams associated with a recurrent positive polarity
Northern hemisphere coronal hole is expected to persist for a
few days. If the Bz component of the IMF turned strongly southward
for prolonged periods, earth could experience Minor Storm conditions
13 October.

INCREASED GEOMAGNETIC ACTIVITY EXPECTED
DUE TO CORONAL HOLE HIGH SPEED WIND STREAM
FOR 14 OCTOBER 2017
_____________________________________________________________

GEOMAGNETIC ACTIVITY FORECAST
14 Oct:  Active to Minor Storm

_____________________________________________________________
SUBJ: SWS AURORA WATCH
ISSUED AT 0031 UT ON 14 Oct 2017 by Space Weather Services
FROM THE AUSTRALIAN SPACE FORECAST CENTRE

Due the current elevated solar wind streams associated with a
recurrent a coronal hole, expect geomagnetic storming to continue over
the next 24 hours with a chance of visible auroras during local
nighttime hours from southernmost Australian regions.


Our Aurora forecasting tool, located at
http://www.sws.bom.gov.au/Aurora/3/1, may help to estimate regions
from where aurora would be visible.

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Friday, October 13, 2017

 

Near Earth Object 2012 TC4 Flys by (12 October 2017)

Asteroid 2012 TC4 imaged with iTelescope T20 on 11 October 2017. MAX stack of  8 x 60 second luminance images, stacked in ImageJ. Over enhanced to show the asteroid. Click to embiggen.Animation of all 8 frames, made with ImageJ. CLick to embiggen.

Five years ago to the day, NEO 2012 TC4 passed 0.2 Earth Moon distances away from us. This time the asteroid was even closer, at 0.13 Earth Moon distances (a mere 50,150 km) and hurtling though the sky at a blistering 13 arc minutes a second. At this speed the iTelescopes cannot track the asteroid. Even with a 60 second exposure the asteroid is a mere streak 45 minutes before closest approach.

I managed to capture it by camping out where the Minor Planet Ephemeris center predicted it would be and waiting until the time it would be predicted to pass across the field of view before imaging.

The asteroid zipped across the field in a mere 12 minutes. The asteroid is a fast rotator, with a period of 12 minutes and 14 seconds, and the asteroid can be seen to dim midfield.

There are quite a few good images of the  asteroid on the web, like this one from the SONEAR observatory.

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Wednesday, October 11, 2017

 

The Sky This Week - Thursday October 12 to Thursday October 19

The Last Quarter Moon is Thursday, October 12. Jupiter is low in the twilight sky.  Saturn is visible most of the evening in the heart of the Milky Way. Venus is now very low in  the morning twilight and forms a line with the crescent Moon and Mars on the 18th.

The Last Quarter Moon is Thursday, October 12.

Evening sky on Saturday October 14 looking north-west as seen from Adelaide at 19:55 ACDST  (30 minutes after sunset). Jupiter is very low above the horizon, deep in the twilight.

Similar views will be seen elsewhere in Australia at the equivalent local time (30 minutes after sunset). (click to embiggen).

Jupiter is setting early evening and is above the western horizon in the twilight. You will need a clear level horizon to see it.

Opposition, when Jupiter is biggest and brightest as seen from Earth, was on April the 8th. Jupiter sets around 8:13 pm local daylight saving time. Jupiter is now too low to be a good telescopic target.

Mercury is lost in the twilight.
 
Evening sky on Saturday October 7 looking west as seen from Adelaide at 20:55 ACDST, 90 minutes after sunset.

The inset shows the telescopic view of Saturn at this time. Similar views will be seen elsewhere in Australia at the equivalent local time. (90 minutes after sunset, click to embiggen).

Saturn was  at opposition on June the 15th, when it was biggest and brightest in the sky as seen from earth. Saturn is visible all evening long. Saturn is a good telescopic target from 9:00 pm daylight saving time until around 11 pm daylight saving time. It is poised next to the dark rifts in the Milky Way and is in a good area for binocular hunting. Although still high in the early evening sky, Saturn begins to sink into the western evening skies as the week progresses.  Saturn's rings are visible even in small telescopes and are always good to view.

The constellation of Scorpio is a good guide to locating Saturn. The distinctive curl of Scorpio is easy to see above the north-western horizon, locate the bright red star, Antares, and the look to the left of  that and slightly above, the next bright object is Saturn.

Morning sky on  Wednesday October 18 looking east as seen from Adelaide at 6:09 ACDST (30 minutes before sunrise). Venus is bright just above the horizon and forms a line with the thin crescent Moon and  Mars.

 Similar views will be seen throughout Australia at the equivalent local time (that is 30 minutes before sunrise, click to embiggen).

Venus  is lowering in the morning sky. This week Venus forms a line with the thin crescent Moon and  Mars. It is becoming hard to see Venus in the early twilight, and you will need a clear unobstructed horizon to see the lineup low in the twilight. 

 Mars is climbing higher the twilight, but sound be reasonably (just) visible this week.

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

Cloud cover predictions can be found at SkippySky.

Here is the near-real time satellite view of the clouds (day and night) http://satview.bom.gov.au/

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Sunday, October 08, 2017

 

Southern Skywatch October 2017 edition is now out!

Morning sky as seen on September 18 half an hour before sunrise. The crescent Moon is close to Venus and forms a triangle with Mars. Similar views will be seen elsewhere in Australia at the equivalent local time. (click to embiggen).

The October edition of Southern Skywatch is  now up. Sorry this is late again, but I was up in QLD with dodgy internet celebrating mum's 95th Birthday.

This month  Mars climbs higher in the morniing sky and is close to Venus.

 Jupiter comes closer to the western horizon and it is lost to view by the end of the month.

Saturn is still high in the early evening sky this month. This is still a good time to watch this ringed world in a telescope, although the window of good observation is narrowing. On the 24th Saturn is close to the  crescent Moon.

Mercury enters the evening sky late this month but is very difficult to see low on the horizon. Next Month it will be very good viewing.

Venus gets lower in the  morning sky this month. The crescent Moon is close to Venus on the 18th, forming a triangle with Mars. Venus is also lost to view by the end of the month.

The Orionid meteor shower is active towards the end of the month, with the best rates in the early morning of the 21st and 22nd.

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Saturday, October 07, 2017

 

Astrophiz Podcast 44 (Galaxy Detective edition) is Out!

Astrophiz Podcast 44 is out now.

To understand how galaxies evolve, Dr Rebecca Allen uses Hubble and Keck images to study star-forming galaxies and galaxies that are not forming stars.

Rebecca’s passion for both outreach and research makes for a exceptional episode as she paints a clear picture of galactic evolution to help us understand some of the fundamental elements of our cosmos.

 For observers and astrophotographers, I continue with ‘What’s Up Doc’ and tells you when, where and what to look for in morning and evening skies. In Ian’s Tangent, I helps you understand more about the new discovery of Binary Comets.

You can follow me  @ianfmusgrave on Twitter and southern skywatch on facebook.

In the News:  
The discovery of the 4th Gravitational Wave announced as a result of a collaboration between researchers at the Italian GW facility and the LIGO detector.

The 2017 Nobel Prize for Physics awarded to 3 men (out of the hundreds of) researchers who created LIGO and the first GW detection.

Dame Jocelyn Bell Burnett still not recognised by the Nobel Committee for her discovery and analysis of Pulsars. That honour was snagged by the bloke who ‘supervised ’her research. 

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Wednesday, October 04, 2017

 

The Sky This Week - Thursday October 5 to Thursday October 12

The Full Moon is Friday October 6 the last Quarter Moon is Thursday, October 12. Jupiter and the bright star Spica are nearby in the early twilight sky.  Saturn is visible all evening in the heart of the Milky Way. Venus is now low in  the morning twilight and is very close to Mars on the 6th.

The Full Moon is Friday October 6 the last Quarter Moon is Thursday, October 12. The Moon is at perigee, closest to the Earth on the 9th.

Evening sky on Saturday October 7 looking north-west as seen from Adelaide at 19:49 ACDST  (30 minutes after sunset). Jupiter is low above the horizon near the bright star Spica.

Similar views will be seen elsewhere in Australia at the equivalent local time (30 minutes after sunset). (click to embiggen).

Jupiter is setting early evening and is above the western horizon in the twilight. It is close to the bright star Spica, the brightest star in the constellation of Virgo. Over the week Jupiter moves away from Spica.

Opposition, when Jupiter is biggest and brightest as seen from Earth, was on April the 8th. Jupiter sets around 8:30 pm local daylight saving time. Jupiter is now too low to be a good telescopic target.

Mercury is lost in the twilight.

Evening sky on Saturday October 7 looking west as seen from Adelaide at 20:50 ACDST, 90 minutes after sunset.

The inset shows the telescopic view of Saturn at this time. Similar views will be seen elsewhere in Australia at the equivalent local time. (90 minutes after sunset, click to embiggen).

Saturn was  at opposition on June the 15th, when it was biggest and brightest in the sky as seen from earth. Saturn is visible all evening long. Saturn is a good telescopic target from 9:00 pm daylight saving time until midnight. It is poised above the dark rifts in the Milky Way and is in a good area for binocular hunting. Although still high in the early evening sky, Saturn begins to sink into the western evening skies as the week progresses.  Saturn's rings are visible even in small telescopes and are always good to view.

The constellation of Scorpio is a good guide to locating Saturn. The distinctive curl of Scorpio is easy to see above the north-western horizon, locate the bright red star, Antares, and the look to the left of  that, the next bright object is Saturn.

Morning sky on  Friday October 6 looking east as seen from Adelaide at 6:19 ACDST (30 minutes before sunrise). Venus is bright just above the horizon and is extremely close to Mars.

 Similar views will be seen throughout Australia at the equivalent local time (that is 30 minutes before sunrise, click to embiggen).

Venus  is lowering in the morning sky. This week Venus comes close to Mars. It is becoming hard to see Venus in the early twilight, but it is still brilliant enough to be obvious shortly before sunrise. Over the Week Venus comes closer to the planet Mars, but you will probably need binoculars to pick up Mars in the twilight. The pair are closest on the 6th, when they are less than half a finger-width apart, they will look good in binoculars, or a small etelscope if you can get it to point that low to the horizon.

 Mars is still emerging from the twilight, but will be difficult to see for some time. It may be more readily visible by the end of the week.

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

Cloud cover predictions can be found at SkippySky.

Here is the near-real time satellite view of the clouds (day and night) http://satview.bom.gov.au/

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