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Monday, November 20, 2017

 

Astrophiz Podcast 47 (Sqaure Kilometer Array edition) is Out!

Astrophiz Podcast 47 is out now.

This episode we are speaking with Dr Phil Edwards, Australia’s SKA leader from the CSIRO. He is now Head of ATNF (Australia Telescope National Facility) Science at the CSIRO and SKA Project Scientist.

Phil is originally from South Australia and did his BSc, BScHons and PhD at the University of Adelaide, and he gives some great insights on the often meandering career paths of scientists.

As well as giving us an inside look at the Square Kilometre Array (the SKA), he explains about a recent discovery of high energy neutrinos from beyond our galaxy. He is one of the Australian members of an international team that follows up some neutrino detections that came about by bugging a cubic kilometre of ice down in the Antarctica. This is big science, using monstrous detectors looking for the tiniest particles that give us new understandings of our cosmos.

For observers and astrophotographers, I tells you what when and where to look for objects in the morning and evening skies, including current meteor showers.

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

In the News: A newly published paper that casts further light on those mysterious FRBs

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Thursday, November 16, 2017

 

Seeing Asteroid 7 Iris from Australia (16-20 November, 2017)

The location of asteroid 7 Iris as seen from Adelaide at local midnight (daylight savings time). Similar views will be seen from the rest of Australia at the equivalent local time. (click to embiggen).

Asteroid 7 Iris is the 4th brightest asteroid, and one of the main belt asteroids. Normally at opposition it is around magnitude 7.8, around the limit of strong binoculars in suburban settings, but this opposition is a favourable one, with the asteroid currently magnitude 7.3, too dim for the unaided eye, but achivable with 10x50 or stronger binoculars and small telescopes under suburban skies.

As well, the asteroid is near some obvious guide stars. The asteroid is near gamma Arietis, the dimmiest of the three bright stars in Aries. At midnight the threes will be almost due north, to the left of the distinctive triangle of the Hyades, the head of Taurus the bull.

Printable black and white chart suitable for binoculars showing the field of view around the three bright stars of Aries. Hamal the brightest star is shown in this chart and the chart above for orientation, the field of view of 10x50 binoculars is shown as the large circle, and the field of view of a 24mm eyepiece with a 114 mm Newtonian reflector is the small circle. The chart is in the same orientation as the chart above (click to embiggen and print).

Gamma Arietis is easily found star hopping up from the obvious Hamal to beta Areitis, then gamma. From the 16th to 20th 7 Iris is the brightest object near gamma Arietis. You may need to watch it from night to night to see it move. On the 22nd it is close to the moderately bright (in binoculars and telescopes anyway, it is just on unaided eye limit) HIP 8689, which is the emext brightest star in the field hopping up from gamma Arietis.

Printable black and white chart suitable for telescopes showing the field of view around gamma Arietis. This chart is in telescope orientsion so is upside down from the two charts above. The field of view of a 24mm eyepiece with a 114 mm Newtonian reflector is the circle. (click to embiggen and print).


The asteroid is at its highest around 11:30 pm (daylight savings time) and is reasonably high for good observation.


Ephemeris of Iris
Date        Mag Ast Twi  Rise     Altitude     Transit  Set      Ast Twi B 
16 Nov 2017 7.2 21:38:35 18:21:32 +35° 35' 02" 23:27:57 04:38:30 04:23:07 
17 Nov 2017 7.3 21:39:56 18:16:40 +35° 35' 39" 23:23:34 04:34:34 04:22:07 
18 Nov 2017 7.3 21:41:18 18:11:51 +35° 35' 00" 23:19:13 04:30:39 04:21:09 
19 Nov 2017 7.3 21:42:39 18:07:04 +35° 33' 07" 23:14:54 04:26:46 04:20:14 
20 Nov 2017 7.3 21:44:00 18:02:20 +35° 30' 00" 23:10:36 04:22:55 04:19:20 
21 Nov 2017 7.4 21:45:21 17:57:38 +35° 25' 41" 23:06:21 04:19:05 04:18:28 
22 Nov 2017 7.4 21:46:41 17:52:58 +35° 20' 11" 23:02:08 04:15:16 04:17:38 
23 Nov 2017 7.4 21:48:01 17:48:22 +35° 13' 32" 22:57:57 04:11:29 04:16:50 
24 Nov 2017 7.5 21:49:19 17:43:48 +35° 05' 46" 22:53:49 04:07:44 04:16:04 
25 Nov 2017 7.5 21:50:38 17:39:17 +34° 56' 55" 22:49:42 04:04:00 04:15:21 
26 Nov 2017 7.5 21:51:55 17:34:48 +34° 46' 59" 22:45:38 04:00:18 04:14:39 
27 Nov 2017 7.6 21:53:12 17:30:23 +34° 36' 02" 22:41:35 03:56:37 04:14:00 
28 Nov 2017 7.6 21:54:27 17:26:00 +34° 24' 05" 22:37:35 03:52:58 04:13:23 
29 Nov 2017 7.6 21:55:42 17:21:40 +34° 11' 10" 22:33:38 03:49:20 04:12:49 
30 Nov 2017 7.6 21:56:55 17:17:23 +33° 57' 19" 22:29:42 03:45:45 04:12:17 
01 Dec 2017 7.7 21:58:07 17:13:09 +33° 42' 35" 22:25:49 03:42:10 04:11:47 
02 Dec 2017 7.7 21:59:18 17:08:58 +33° 27' 00" 22:21:58 03:38:37 04:11:20 
03 Dec 2017 7.7 22:00:27 17:04:50 +33° 10' 35" 22:18:09 03:35:06 04:10:56 
04 Dec 2017 7.8 22:01:35 17:00:45 +32° 53' 23" 22:14:22 03:31:36 04:10:34 
05 Dec 2017 7.8 22:02:42 16:56:42 +32° 35' 25" 22:10:38 03:28:08 04:10:15 

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Wednesday, November 15, 2017

 

Leonid Meteor Shower, November 17-18, 2015

North-eastern horizon at around 4:00 am (daylight saving time, 3:00 am standard time) on the morning of Saturday, November 18 (click to embiggen). The starburst indicates the radiant, the apparent point of origin of the meteors (they can actually first appear much further away from the radiant).

The Leonids are an iconic meteor shower due to spectacular displays in 1833, 1966, 2001 and 2002. They are due to dusty debris from Comet Tempel-Tuttle slamming into Earth's atmosphere. While occasional Leonid meteors can be seen most of November, the rate rises to a peak in mid-November. However, the spectacular rates of the storm years are long gone and will not reoccur for some time, For the foreseeable future only the occasional meteor will be seen, even at the peak.

This year the peak is on Saturday, November 18, with estimates of between 10-15 ZHR (Zenithal Hourly Rate - the number of meteors you could expect to see if the radiant was at the Zenith under dark skies). However, the radiant never gets very high in Australia, and although the peak occurs 3:30 am in Australia, we expect to see far fewer meteors than the ZHR. Somewhere in the range of one meteor every 20 minutes is likely even under dark skies. However, this year the meteors are expected to be quite bright.


As well, this year there may be an early peak. The IMO is advising of possible enhanced Leonids activity on November 17 at 4 am AEDST ( November 16, 17h07m UT), this is November. A ZHR of 12 composed of brighter than usual meteors may be seen (this translates to about a meteor every 15 minutes).

While we can expect to see very few meteors, the morning will be a beautiful sight anyway.Orion the Hunter is stretched out overhead, and the Pleiades nearby. You might even see a satellite or two (but not the ISS or iridium flares). To check the weather forecast, go to the Meterology Departments forecast site, or alternately the Weather Channel.

When to look: The best time is between 3:00 am to 5:00 am daylight saving time (2-4 am standard time) on the mornings of the 17th to 18th.

Where to look: Face north-east. About five hand spans above the horizon you should see bright Saturn. A hand span to the right brings you to the bright white star Alpha Leonis, Regulus. Following down and to the left from Regulus you will see a number of fainter stars which form a sickle shape, the head of the lion. The radiant of the Leonid shower will be roughly in the center of the curve of the sickle, about one finger width up (see image above). However, the meteors can turn up almost anywhere in the eastern half of the sky, so make sure you have a spot with a fairly clear field of view, without any bright street-lights in the way. Use common sense in choosing a viewing site. Lone persons should not choose dark parks in the seedy part of town to watch the Leonids, as a mugging can ruin your entire day.

What do you need: For meteor watching, very little is needed. Basically, all you need is you. If you want to try and count the meteors, you will need a couple of sheets of paper, a pencil and a good watch. Bundle up against the pre-dawn cold, warns shoes, thick socks, sensible pants and a good jumper and possibly a blanket to wrap yourself in (I really mean this, last time I had a jumper and a windproof and I was seriously cold). Bring a reclining chair if you have one, or just a picnic chair or a good picnic blanket, and find a dark site with a wide-open view of the sky. Then just lie back, relax, and look up at the stars. Optional extras are a torch with red cellophane over the business end (otherwise you ruin your night vision everytime you turn it on), and a thermos of something warm to drink. Mosquito repellent is also a very good idea.

Give it some time: Many people wander out, look around for five minutes, see nothing and wander back in. It will take about five minutes for your eyes to become accustomed to the dark. Also, meteors tend to come in bursts, and if you wander out in a lull, you may miss lots. As well, our time perception sucks. You may think you have been watching for 10 minutes, but in reality only about 2 minutes has passed. Give it time, watch the stars, and enjoy.

IMO Leonids Live! IMO weekly meteor outlook.

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Tuesday, November 14, 2017

 

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

The New Moon is Saturday, November 18.  Mercury climbs higher in the evening twilight and forms a line with Antares and Saturn low in the early evening sky.  On the 20th Mercury, Saturn and the crescent Moon make a triangle, on the 21st The Moon, Saturn, Mercury and Antares form a line. Venus is now very low in  the morning twilight. Venus, Jupiter and the thin crescent Moon are very close on the on the 18th.  Leonid meteor shower peaks this week.

The New Moon is Saturday, November 18. The Moon is at apogee, when it is furthest from the Earth, on the 22nd.

Evening sky on Monday November 20 looking north-west as seen from Adelaide at 21:06 ACDST  (60 minutes after sunset). Mercury is low above the horizon and forms a triangle with with Saturn and the thin crescent Moon.

Similar views will be seen elsewhere in Australia at the equivalent local time (60 minutes after sunset). (click to embiggen).

Mercury is visible in early evening and is above the western horizon in the late twilight. Mercury is becoming more prominent, and is well worth watching as it rises into the evening sky up the body of the Scorpion. This week it forms a line with bright star Antares in the body of the scorpion and Saturn. On the 20th Mercury, Saturn and the crescent Moon make a triangle, on the 21st The Moon, Saturn, Mercury and Antares form a line.. Mercury is visible well after civil twilight, but you need a clear level horizon to see it at its best.

Saturn is visible in the early evening setting around 10:30 pm local time. Saturn is no longer a viable telescopic target, being too close to the horizon when the sky is fully dark. Saturn continues to sink into the western evening skies as the week progresses but the line up with the crescent Moon on the21st is very nice. 

The constellation of Scorpio is still a good guide to locating Saturn. The distinctive curl of Scorpio is setting but still projects above the north-western horizon, locate the bright red star, Antares, and the look to the left of  that and above, the next bright object is Saturn. Antares is only briefly visible in the twilight though.

Morning sky on  Saturday November 18 looking east as seen from Adelaide at 5:33 ACDST (30 minutes before sunrise). Venus is bright just above the horizon and forms a triangle  with the thin crescent Moon and Jupiter.

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

Venus  continues to lower in the morning sky. This week Venus is close to Jupiter the crescent Moon. It is becoming very difficult to see Venus in the twilight, and you will need a clear unobstructed horizon to see the Venus low in the twilight.

Jupiter climbs higher in the morning twilight and is close to Venus and the crescent Moon on 18th. You will need a clear, level unobstructed horizon, like the ocean or desert, to see this, and you will need binoculars to pick up Jupiter.

 Mars is climbing higher the twilight, and is now reasonably visible in the twilight.
  
Morning sky looking north-east as seen from Adelaide at 4:00 am local daylight saving time on Wednesday November 18 and Thursday November 189 showing Jupiter, Mars and Venus near Leo, with the Leonid Meteor shower radiant indicated with a starburst. Similar views will be seen elsewhere at the equivalent local time. Click to embiggen.

On the morning of Saturday November 18 the Leonid Meteor shower peaks (from the point of view of Australians, that's 17 November UT), with the best time being between 3-4 am. However, there may be another peak on the morning of the 16th (16th UT)

Despite the peaks, very few meteors will be visible (maybe one every 5-10 minutes).

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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A year without Jack



A year ago today, sometime in the early morning, our sonJack died. A year ago, stunned, shocked, uncomprehending we flew out of Adelaide, into Melbourne and a world without Jack. A year on, many tests later we still do not know why he died. Something like 50% of all sudden deaths in young healthy people never do have definitive explanations. The most likely explanation is a rogue electrical storm seized his heart. 

We have been tested for the commonest forms of heritable heart disease that can cause such lethal storms. We are all clear of them, MiddleOne at the very least is free of these forms, and is probably no more likely than most people to succumb to a cardiac storm. 

Can you imagine what it would be like to be a teenager with that hanging over you? Exams, career planning none of that matters when your future could be taken from you in an instant. Now the Damocles sword has been removed and life can move on past the year without Jack. 

A year without Jack. The final anniversary in the dreadful countdown but not the end of the process. There will always be a gap, a space where Jack was. A bus station where he will not arrive, a fencing club he will not go to, a phone number that will not answer. 

We can navigate that space now, rather than tiptoe around it as we move into the future. Our friends and Jacks friends, our family, the Farrago community and the Medley community have all worked together to find our paths around this gap. We will continue to journey on. Jacks friends will branch out into the wider world, continuing to forge their identities, facing new challenges, new successes and failures (for how do we learn if we do not fail occasionally). Possibly wearing pink fencing socks.

His brothers too are charting their own futures in their own ways. They will make their own impacts, whether in music or some other sphere, enriching the lives they touch. Not in the same way Jack enriched others’ lives, but in their own special ways. One year past Jack the future beckons. 

A year without Jack, but a year with his stories. Hopefully his stories, his beautiful powerful stories, will inspire people to continue on the journey started by Brave Ulysses and the world will in fact not be without Jack.

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Wednesday, November 08, 2017

 

Another good Week for ISS passes, (9 November - 16 November 2017)

The ISS passes below Saturn, as seen from Melbourne on the evening of Sunday 12 November at 22:23 AEST. Simulated in Stellarium (the ISS will actually be a bright dot), click to embiggen.The ISS passes near the tail of Scorpius, as seen from Adelaide on the evening of Sunday 12 November at 22:52 ACST. Simulated in Stellarium (the ISS will actually be a bright dot), click to embiggen.The ISS passes between the pointers and the tail of Scorpius, as seen from Perth on the evening of  Sunday 12 November at 19:55 AWST. Simulated in Stellarium (the ISS will actually be a bright dot), click to embiggen.
All sky chart showing local times from Heavens Above for Sunday 12 November for Melbourne.All sky chart showing local  times from Heavens Above for Sunday 12 November for Adelaide.All sky chart showing local times from Heavens Above for Sunday 12 November for Perth.

Starting Thursday there are a series of bright evening passes of the International Space Station lasting around seven days. Some are low to the horizon, some rapidly enter earth's shadow, but for many places in Australia this series has the ISS gliding either close to Saturn or a series of bright stars (except Darwin, which only gets three bright evening passes low above the horizon).
 
The ISS passes extremely close to the bright stars alpha and Beta Centauri and Fomalhaut during some of these passes (check your local predictions). The following tables are from data provided from Heavens Above.

Passes from Adelaide

Date Brightness Start Highest point End Pass type
(mag) Time Alt. Az. Time Alt. Az. Time Alt. Az.
08 Nov-1.621:08:4810°SSW21:11:0717°SSE21:12:3314°ESEvisible
08 Nov-0.722:44:3410°WSW22:45:1215°WSW22:45:1215°WSWvisible
09 Nov-3.221:52:2010°SW21:55:0655°SSW21:55:0655°SSWvisible
10 Nov-2.721:00:2010°SSW21:03:2735°SE21:05:0322°Evisible
10 Nov-0.722:37:2310°W22:37:4312°W22:37:4312°Wvisible
11 Nov-2.821:44:3510°WSW21:47:4237°NW21:47:4237°NWvisible
12 Nov-3.820:52:1210°SW20:55:3485°NW20:57:4520°NEvisible
13 Nov-1.321:37:4110°W21:39:3014°NW21:40:3212°NNWvisible
14 Nov-2.120:44:3110°WSW20:47:2728°NW20:50:2210°NNEvisible
16 Nov-0.820:38:2310°WNW20:39:0911°NW20:39:5410°NWvisible
Passes from Brisbane

Date Brightness Start Highest point End Pass type
(mag) Time Alt. Az. Time Alt. Az. Time Alt. Az.
08 Nov-0.420:42:2510°SSW20:42:3311°S20:42:3311°Svisible
09 Nov-1.119:51:3010°SSE19:52:2711°SSE19:52:2711°SSEvisible
10 Nov-1.020:33:5710°SW20:35:0319°SSW20:35:0319°SSWvisible
11 Nov-2.419:42:0710°SSW19:45:0227°SE19:45:0227°SEvisible
12 Nov-1.518:50:4510°S18:52:4114°SE18:54:3510°ESEvisible
12 Nov-1.520:26:0910°WSW20:27:4523°WSW20:27:4523°WSWvisible
13 Nov-3.919:33:4610°SW19:37:0787°SE19:37:5151°NEvisible
14 Nov-2.918:41:4510°SSW18:44:5235°SE18:47:5710°ENEvisible
14 Nov-0.920:19:4410°W20:20:4212°WNW20:20:4212°WNWvisible
15 Nov-2.019:26:0610°WSW19:28:5827°NW19:30:5715°Nvisible
 
 
Passes from Melbourne

Date Brightness Start Highest point End Pass type
(mag) Time Alt. Az. Time Alt. Az. Time Alt. Az.
08 Nov-3.021:38:4010°SW21:41:5442°SE21:42:3337°ESEvisible
09 Nov-2.120:46:4410°SSW20:49:3625°SSE20:52:2610°Evisible
09 Nov-2.022:23:0210°WSW22:25:0628°W22:25:0628°Wvisible
10 Nov-3.821:30:4110°SW21:34:0377°NW21:35:0342°NEvisible
11 Nov-3.320:38:3210°SW20:41:5153°SE20:45:0210°ENEvisible
11 Nov-1.222:16:0810°W22:17:4214°WNW22:17:4214°WNWvisible
12 Nov-2.221:23:0310°WSW21:25:5928°NW21:27:4517°Nvisible
14 Nov-1.021:16:4410°WNW21:17:4311°NW21:18:4010°NWvisible
Passes from Perth

Date Brightness Start Highest point End Pass type
(mag) Time Alt. Az. Time Alt. Az. Time Alt. Az.
08 Nov-1.220:12:4910°S20:14:1812°SSE20:15:1211°SEvisible
08 Nov-0.221:47:4710°SW21:47:5211°SW21:47:5211°SWvisible
09 Nov-2.120:55:4010°SW20:57:4632°SSW20:57:4632°SSWvisible
10 Nov-2.320:03:4910°SSW20:06:4226°SE20:07:4322°ESEvisible
11 Nov-2.720:47:4610°SW20:50:2242°W20:50:2242°Wvisible
12 Nov-3.819:55:3010°SW19:58:5070°SE20:00:2528°ENEvisible
13 Nov-1.520:40:3810°W20:42:5117°NW20:43:1216°NWvisible
14 Nov-2.619:47:4010°WSW19:50:4636°NW19:53:2313°NNEvisible
16 Nov-1.019:40:5710°W19:42:2913°NW19:44:0210°NNWvisible

Passes from Sydney


Date Brightness Start Highest point End Pass type
(mag) Time Alt. Az. Time Alt. Az. Time Alt. Az.
08 Nov-2.021:40:2510°SSW21:42:3330°S21:42:3330°Svisible
09 Nov-2.020:48:3610°SSW20:51:2123°SE20:52:2719°ESEvisible
09 Nov-0.522:24:5210°WSW22:25:0611°WSW22:25:0611°WSWvisible
10 Nov-1.319:57:0510°S19:58:5714°SSE20:00:4810°ESEvisible
10 Nov-2.921:32:2510°SW21:35:0349°WSW21:35:0349°WSWvisible
11 Nov-3.420:40:1610°SW20:43:3454°SE20:45:0228°ENEvisible
12 Nov-1.921:24:5810°WSW21:27:3922°NW21:27:4522°NWvisible
13 Nov-3.120:32:1910°WSW20:35:3549°NW20:37:5117°NNEvisible
15 Nov-1.320:25:0310°W20:27:2117°NW20:29:3810°Nvisible
   
When and what you will see is VERY location dependent, so you need to use either Heavens Above or CalSky to get site specific predictions for your location, a small difference in location can mean the difference between the ISS passing over a star or missing it completely.
 
Start looking several minutes before the pass is going to start to get yourself oriented and your eyes dark adapted. Be patient, there may be slight differences in the time of the ISS appearing due to orbit changes not picked up by the predictions. Use the most recent prediction for your site.

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The Sky This Week - Thursday November 9 to Thursday November 16

The Last Quarter Moon is Saturday, November 11.  Mercury climbs higher in the evening twilight and meets Antares on the 13th. Saturn is visible in the low in the early evening sky.  Venus is now very low in  the morning twilight and is close to Jupiter on the 13th. Mars is close to the Moon on the 15th, a series of bright ISS passes starts on the 9th. Leonid meteor shower peaks next week.

The Last Quarter Moon is Saturday, November 11.

Evening sky on Monday November 13 looking north-west as seen from Adelaide at 20:45 ACDST  (45 minutes after sunset). Mercury is low above the horizon close to the star Antares with Saturn above.

Similar views will be seen elsewhere in Australia at the equivalent local time (45 minutes after sunset). (click to embiggen).

Mercury is visible in early evening and is above the western horizon in the late twilight. Mercury is becoming more prominent, and is well worth watching as it rises into the evening sky up the body of the Scorpion. This week it comes close to the bright star Antares in the body of the scorpion on the 13th. This is the second of an interesting series of encounters over the coming weeks. Mercury is visible well after civil twilight, but you need a claer level hoizon to see it at its best.



Saturn is visible in the early evening setting around 10:30 pm local time. Saturn is no longer a viable telescopic target, being too close to the horizon when the sky is full dark. Saturn continues to sink into the western evening skies as the week progresses. 

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

Morning sky on  Monday November 13 looking east as seen from Adelaide at 5:36 ACDST (30 minutes before sunrise). Venus is bright just above the horizon and forms a line with Mars and the Moon. Jupiter is very close to Venus.

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

Venus  continues to lower in the morning sky. This week Venus is close to Jupiter and forms a line with  Mars and the crescent Moon. It is becoming much harder to see Venus in the twilight, and you will need a clear unobstructed horizon to see the Venus low in the twilight. 


Jupiter enters the morning twilight and is close to Venus on the 13th. You will need a clear, level unobstructed horizon, like the ocean or desert, to see the, and you will need binoculars to pick up Jupiter. .

 Mars is climbing higher the twilight, and is now reasonably visible in the twilight. It is visited by the crescent Moon on the 15th.



Evening sky on Sunday November 12 looking north-west as seen from Adelaide at 20:54 ACDST . Mercury is low above the horizon close to the star Anatres with Saturn above. The International Space Station passes next to them.




This week  there are a series of bright evening passes of the International Space Station. Some are low to the horizon others pass close to bright stars. When and what you will see is VERY location dependent, so you need to use either Heavens Above or CalSky to get site specific predictions for your location.

  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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Tuesday, November 07, 2017

 

Aurora Visible NOW! and G1 storm alert (7 November)

Aurora have been reported from multiple sites in Tasmania with beams, and unconfirmed reports of aurora in Bendigo and ACT. There is a current G1 storm alert. This is despite the conditions for aurora being marginal, Velocity: 426 km/sec Bz: -4.0 nT Density = 24.0 p/cc  but with dark skies it will be well worth having a look. The SWS predicts active conditions will continue for the next day or so. The Space Weather Prediction Service has Predicted a G1 storm around now and the current Kindex is 5 (hence the G1 storm alert).

If the Bz becomes more negative aurora may become more widespread and intense. The Moon is waning, and will not significantly interfere with aurora in the early part of the evening. Especially now be patient, as the activity may rise and fall of the magnetic polarity of the wind may fluctuate significantly.

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 last weeks 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 ALERT
ISSUED AT 1040 UT ON 07 NOV 2017 BY SPACE WEATHER SERVICES
FROM THE AUSTRALIAN SPACE FORECAST CENTRE

MINOR (G1 - MINOR) GEOMAGNETIC DISTURBANCE IN PROGRESS (K OF 5 REACHED)
PRELIMINARY AUSTRALIAN REGION K INDICES FOR 07 11 17: 1335 ----


FOLLOW THE PROGRESS OF THIS EVENT ON THE SWS SPACE WEATHER STATUS PANEL,
HTTP://WWW.SWS.BOM.GOV.AU > SPACE WEATHER

-------------------------------------------------------------------------
SUBJ: SWS AURORA WATCH
ISSUED AT 0256 UT ON 06 Nov 2017 by Space Weather Services
FROM THE AUSTRALIAN SPACE FORECAST CENTRE

Effects of a recurrent coronal hole are expected to impact the Earth
within the next 48 hours, possibly resulting in significant
geomagnetic activity and visible auroras during local nighttime hours.
Aurora alerts will follow if significant geomagnetic activity actually
occurs.
---------------------------------------------------------------------------------------------------

SUBJ: SWS GEOMAGNETIC DISTURBANCE WARNING 17/54
ISSUED AT 0242UT/06 NOVEMBER 2017
BY THE AUSTRALIAN SPACE FORECAST CENTRE.

A recurrent northern hemisphere coronal hole will soon reach
the geoeffective location on the solar disk. A corotating interaction
region associated with the coronal hole is expected to effect
Earth from late UT day 6 November. On the subsequent two days
(7-8 November) Active to Minor Storm conditions may occur provided
IMF Bz will turn southward for a prolonged period.

INCREASED GEOMAGNETIC ACTIVITY EXPECTED
DUE TO CORONAL HOLE HIGH SPEED WIND STREAM
FROM 07-08 NOVEMBER 2017
_____________________________________________________________

GEOMAGNETIC ACTIVITY FORECAST
07 Nov:  Active
08 Nov:  Active



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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Saturday, November 04, 2017

 

Comet 96P/Machholz zooms past the sun

Single image of comet 96P Machholz from the SOHO LASCO C3 instrument on 27 October 2017. Click on any image to embiggenComposte series of images as the comet swung around the sun fro 26-28 October. The gap is where some images were not takenAnimation of the same series.

Comet 96P/Machholz came to perihelion on October 27, unfortunately, it was too close to the sun for us Earth-bound observers, but fortunately a bevy of sun-observing spacecraft watched intently as it passed by. It was picked up by the Solar and Heliospheric Observatory (SOHO) and the Solar TErrestrial RElations Observatory Ahead (STEREO-A) spacecraft.

This visitation wasn't as spectacular as the one in 2002, but was very interesting nonetheless. Most importantly, high-resolution images from SOHO LASCO 3 showed the presence of 3 fragments.

Two of these fragments had been seen in the 2012 passage of the comet, the third was new.

You can read about the background to the comet, other observations and its fragmentation in far more detail at the excellent skyhunt blog (go now, you won't be disappointed, I'll wait).
I won't try and duplicate Trygve Prestgard's excellent work,I will just presnt my images from the STEREO spacecraft where I hunted for the fragments. Despite high resolution COR2A images, I found no fragments.

Comet 99P Macholz in the STEREO COR2 Imager on 26 OctoberAnimation of 26 October images, note tail movement

Single image of STEREO COR2A from 28 October, 2017Animation of 28 October images

Comet 96P Machholz in the STEREO H1A imager on 23 October (right down the bottom left) click to emggenAnimation of the comets brief sojourn in the H1A imager field of view

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