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Thursday, December 12, 2019

 

An unusual series of Bright ISS passes (14-19 December, 2019)

The ISS just before it enters Earth's shadow as seen from Sydney on the evening of Saturday 14 December  at 22:38 AEDST. Simulated in Stellarium (the ISS will actually be a bright dot), click to embiggen.The ISS  before it enters Earth's shadow as seen from Adelaide on the evening of Saturday 14 December  at at 22:38 ACDST. Simulated in Stellarium (the ISS will actually be a bright dot), click to embiggen.The ISS passes close to Canopus, as seen from Perth on the evening of Saturday 14 December at 21:13 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 Saturday 14 December  for Sydney.All sky chart showing local  times from Heavens Above for Saturday 14 December for Adelaide.All sky chart showing local times from Heavens Above for Saturday 14 December for Perth.

Over the next few days there are a series of  bright ISS passes in the early evening where you get to see something not exactly common. The ISS entering and leaving the Earths shadow. Seeing the ISS wink out as it slides into earths shadow is relatively common, but to see it reappear again is much rarer. This will be  seen on the 14th for most of the east coast and south Australia. 

Aside from this, on the 15 the ISS passs through Orion in many cities, there are some close bright star passes and from Brisbane there is a close pass to Venu on the 16th. 

The following tables are from data provided from Heavens Above.

Passes from Adelaide (ACDST)

Date Brightness Start Highest point End Pass type
(mag) Time Alt. Az. Time Alt. Az. Time Alt. Az.
12 Dec-0.505:27:2910°S05:29:1613°SSE05:31:0310°ESEvisible
14 Dec-0.300:34:5112°SSW00:35:0312°SSW00:36:2510°Svisible
14 Dec-1.305:26:1510°SSW05:29:1728°SE05:32:1610°Evisible
14 Dec-3.322:05:5610°NNW22:10:0044°E22:12:3910°SEvisible
14 Dec-0.723:43:5510°WSW23:46:1617°SSW23:48:3710°SSEvisible
15 Dec-0.604:38:0510°SSW04:40:3518°SSE04:43:0310°ESEvisible
15 Dec-2.821:17:5210°NNW21:20:5028°NE21:23:4910°ESEvisible
15 Dec-1.422:54:3610°W22:57:3226°SW23:00:3010°SSEvisible
16 Dec-0.303:50:1010°S03:51:4813°SSE03:53:2610°SEvisible
16 Dec-3.705:25:3410°SW05:29:0087°SE05:32:2210°NEvisible
16 Dec-2.422:05:3610°WNW22:08:5243°SW22:12:1110°SEvisible
17 Dec-2.504:37:0610°SW04:40:2545°SE04:43:4110°ENEvisible
17 Dec-3.621:16:5210°NW21:20:1783°SW21:23:4310°SEvisible
17 Dec-0.222:55:5510°SW22:57:2913°SSW22:59:0410°Svisible
18 Dec-1.403:48:4610°SSW03:51:4426°SE03:54:4010°Evisible
18 Dec-2.705:25:3110°WSW05:28:2626°NW05:31:1810°Nvisible
18 Dec-0.622:06:1310°WSW22:08:4018°SSW22:11:0910°SSEvisible
19 Dec-0.703:00:3610°SSW03:02:5917°SSE03:05:2210°ESEvisible
19 Dec-3.704:36:3710°WSW04:39:5752°NW04:43:1410°NNEvisible
19 Dec-1.321:16:5510°W21:19:5528°SW21:22:5710°SSEvisible
20 Dec-0.302:12:4310°S02:14:0912°SSE02:15:3610°SEvisible
20 Dec-3.703:47:5810°SW03:51:2378°SE03:54:4610°NEvisible
21 Dec-0.702:59:2910°SW02:59:4311°SSW02:59:4311°SSWvisible
21 Dec-0.421:18:0010°WSW21:19:4513°SSW21:21:3210°Svisible


Passes from Brisbane (AEST)

Date Brightness Start Highest point End Pass type
(mag) Time Alt. Az. Time Alt. Az. Time Alt. Az.
14 Dec-3.520:00:2810°NNW20:03:4346°NE20:03:5545°ENEvisible
14 Dec-0.421:39:5912°SW21:40:3813°SW21:42:1710°Svisible
15 Dec-0.904:11:5210°SSW04:14:4023°SE04:17:2610°Evisible
15 Dec-2.519:12:3910°N19:15:2022°NE19:18:0310°ESEvisible
15 Dec-1.120:49:1510°W20:51:5922°SW20:54:4310°SSEvisible
16 Dec-0.303:24:1310°S03:26:0214°SE03:27:4910°ESEvisible
16 Dec-2.320:00:1010°WNW20:03:2341°SW20:06:4010°SSEvisible
17 Dec-3.704:11:0210°SW04:14:2887°ESE04:17:4810°NEvisible
17 Dec-3.719:11:2810°NW19:14:5288°SW19:18:1810°SEvisible
18 Dec-2.303:22:4110°SSW03:25:5540°SE03:29:0710°ENEvisible
18 Dec-0.320:01:2410°WSW20:03:1614°SW20:05:1010°Svisible
19 Dec-1.102:34:3610°SSW02:37:1821°SE02:39:5810°Evisible
19 Dec-2.504:11:1610°WSW04:13:5622°NW04:16:3610°Nvisible
19 Dec-0.919:11:4610°W19:14:3524°SW19:17:2610°SSEvisible
20 Dec-0.301:47:0210°S01:48:3713°SE01:50:1010°ESEvisible
20 Dec-3.603:22:1510°SW03:25:3146°NW03:28:4410°NNEvisible


Passesfrom Darwin (ACDT)

Date Brightness Start Highest point End Pass type
(mag) Time Alt. Az. Time Alt. Az. Time Alt. Az.
14 Dec-1.819:25:4810°NNE19:27:1012°NE19:28:3210°Evisible
14 Dec-1.321:00:5210°WNW21:03:4024°SW21:06:2910°Svisible
15 Dec-3.020:11:5210°NW20:15:1056°SW20:18:3110°SSEvisible
17 Dec-0.505:18:1310°S05:20:3318°SE05:22:5310°Evisible
17 Dec-0.220:13:1510°WSW20:14:5413°SW20:16:3410°SSWvisible
19 Dec-3.805:16:5110°SW05:20:1385°ESE05:23:3210°NEvisible
20 Dec-2.004:28:3710°SSW04:31:4233°SE04:34:4510°ENEvisible


Passes from Hobart (AEDST)

Date Brightness Start Highest point End Pass type
(mag) Time Alt. Az. Time Alt. Az. Time Alt. Az.
12 Dec-2.501:08:0342°S01:08:0342°S01:11:0110°SEvisible
12 Dec-1.002:42:2710°SW02:45:0420°S02:47:4010°SEvisible
12 Dec-1.204:19:4910°SW04:22:3923°SSE04:25:2910°ESEvisible
13 Dec-2.400:20:2535°SE00:20:2535°SE00:22:3610°SEvisible
13 Dec-1.201:53:3710°WSW01:56:2322°SSW01:59:0910°SEvisible
13 Dec-0.903:31:1910°SW03:33:5920°S03:36:3810°ESEvisible
13 Dec-2.423:32:1031°ESE23:32:1031°ESE23:34:0710°ESEvisible
14 Dec-1.501:04:5511°WSW01:07:4326°SSW01:10:4110°SEvisible
14 Dec-0.802:42:4410°SW02:45:1719°S02:47:4910°SEvisible
14 Dec-2.004:19:3110°SW04:22:4436°SSE04:25:5510°Evisible
14 Dec-3.522:39:5918°NNW22:42:1444°NE22:45:3310°ESEvisible
15 Dec-2.000:15:5310°W00:19:0433°SSW00:22:1510°SEvisible
15 Dec-0.801:54:0010°SW01:56:3319°S01:59:0510°SEvisible
15 Dec-1.403:31:0510°SW03:34:0628°SSE03:37:0610°Evisible
15 Dec-2.721:50:5710°NNW21:53:5226°NE21:56:4710°ESEvisible
15 Dec-2.723:27:0810°WNW23:30:2747°SSW23:33:5010°SEvisible
16 Dec-0.901:05:1110°WSW01:07:4920°S01:10:2710°SEvisible
16 Dec-1.102:42:3610°SW02:45:2523°SSE02:48:1310°ESEvisible
16 Dec-3.504:19:0910°SW04:22:3577°SSE04:26:0010°ENEvisible
16 Dec-3.522:38:2810°WNW22:41:5472°SSW22:45:2110°SEvisible
17 Dec-1.100:16:1810°WSW00:19:0622°SSW00:21:5410°SEvisible
17 Dec-0.901:54:0210°SW01:56:4220°S01:59:2010°ESEvisible
17 Dec-2.703:30:4010°SW03:34:0249°SSE03:37:2110°ENEvisible
17 Dec-3.821:49:5810°NW21:53:2370°NE21:56:5010°ESEvisible
17 Dec-1.423:27:2310°WSW23:30:2327°SSW23:33:2410°SEvisible
18 Dec-0.801:05:2310°SW01:07:5719°S01:10:2910°SEvisible
18 Dec-2.002:42:1210°SW02:45:2535°SSE02:48:3510°Evisible
18 Dec-3.304:18:5710°WSW04:22:1240°NW04:25:2510°NNEvisible
18 Dec-1.922:38:3010°W22:41:4335°SSW22:44:5610°SEvisible
19 Dec-0.800:16:3710°SW00:19:1119°S00:21:4310°SEvisible
19 Dec-1.501:53:4410°SW01:56:4327°SSE01:59:4210°ESEvisible
19 Dec-3.903:30:1910°WSW03:33:4470°NW03:37:0710°NEvisible
19 Dec-2.621:49:4210°WNW21:53:0450°SSW21:56:2710°SEvisible
19 Dec-0.923:27:4510°WSW23:30:2420°S23:33:0310°SEvisible
20 Dec-1.101:05:1210°SW01:08:0022°SSE01:10:4610°ESEvisible
20 Dec-3.502:41:4510°SW02:45:1272°SSE02:48:3610°ENEvisible
20 Dec-2.104:19:2510°W04:21:3416°NW04:23:4110°Nvisible
20 Dec-1.122:38:4810°WSW22:41:3823°SSW22:44:2910°SEvisible
21 Dec-0.900:16:3610°SW00:19:1420°S00:21:5110°ESEvisible
21 Dec-2.701:53:1410°SW01:56:3546°SSE01:57:2637°ESEvisible
21 Dec-1.421:49:5110°W21:52:5328°SSW21:55:5610°SEvisible
21 Dec-0.923:27:5310°SW23:30:2619°S23:32:5810°SEvisible


Passes from Melbourne (AEDST)

Date Brightness Start Highest point End Pass type
(mag) Time Alt. Az. Time Alt. Az. Time Alt. Az.
12 Dec-0.801:08:0418°S01:08:0418°S01:09:2810°SSEvisible
13 Dec-0.900:20:2515°SSE00:20:2515°SSE00:21:1410°SEvisible
13 Dec-0.301:54:4010°SSW01:55:3411°SSW01:56:2810°Svisible
13 Dec-0.805:08:4910°SSW05:11:3021°SSE05:14:0910°ESEvisible
13 Dec-1.123:32:1015°SE23:32:1015°SE23:32:5310°SEvisible
14 Dec-0.401:04:5910°SW01:06:4813°SSW01:08:3610°SSEvisible
14 Dec-0.504:20:4110°SSW04:22:4815°SSE04:24:5510°ESEvisible
14 Dec-3.922:37:3410°NW22:40:5974°NE22:44:2510°SEvisible
15 Dec-0.800:15:3810°WSW00:18:0418°SSW00:20:3110°SSEvisible
15 Dec-0.303:32:3910°S03:34:0212°SSE03:35:2510°SEvisible
15 Dec-2.405:08:1010°SW05:11:3045°SE05:14:4510°ENEvisible
15 Dec-3.321:49:2110°NNW21:52:3339°NE21:55:4710°ESEvisible
15 Dec-1.323:26:2910°W23:29:2225°SSW23:32:1810°SSEvisible
16 Dec-1.504:19:5110°SSW04:22:5328°SSE04:25:5410°Evisible
16 Dec-2.222:37:3010°WNW22:40:4538°SSW22:44:0010°SEvisible
17 Dec0.000:17:1210°SSW00:18:1611°SSW00:19:2110°Svisible
17 Dec-0.803:31:3610°SSW03:34:1320°SSE03:36:4810°ESEvisible
17 Dec-3.705:07:5010°WSW05:11:1258°NW05:14:3110°NEvisible
17 Dec-3.321:48:4610°WNW21:52:1066°SW21:55:3610°SEvisible
17 Dec-0.323:27:3310°SW23:29:2814°SSW23:31:2310°SSEvisible
18 Dec-0.402:43:2610°SSW02:45:2815°SSE02:47:2910°ESEvisible
18 Dec-3.604:19:1610°SW04:22:4375°SE04:26:0510°NEvisible
18 Dec-0.722:38:1110°WSW22:40:4119°SSW22:43:1310°SSEvisible
19 Dec-0.101:55:2310°S01:56:3912°SSE01:57:5510°SEvisible
19 Dec-2.403:30:5010°SW03:34:0842°SE03:37:2310°ENEvisible
19 Dec-2.305:08:1110°W05:10:3919°NW05:13:0510°Nvisible
19 Dec-1.221:49:0010°W21:51:5726°SSW21:54:5710°SSEvisible
20 Dec-1.502:42:2910°SSW02:45:2827°SSE02:48:2610°Evisible
20 Dec-3.104:19:0710°WSW04:22:1534°NW04:25:2010°NNEvisible
20 Dec-0.322:39:3310°SW22:40:4811°SSW22:42:0210°Svisible
21 Dec-1.001:54:1210°SSW01:56:4519°SSE01:57:2618°SEvisible
21 Dec-0.521:49:5510°WSW21:51:5715°SSW21:53:5810°SSEvisible


Passes from Perth (AWST)

Date Brightness Start Highest point End Pass type
(mag) Time Alt. Az. Time Alt. Az. Time Alt. Az.
14 Dec-0.704:30:0910°SSW04:32:5121°SE04:35:3010°Evisible
14 Dec-3.821:08:2610°NW21:11:5088°SW21:15:1710°SEvisible
14 Dec-0.222:48:0710°SW22:49:0211°SSW22:49:5610°SSWvisible
15 Dec-0.303:42:2210°S03:44:1013°SSE03:45:5610°ESEvisible
15 Dec-3.420:20:0910°NNW20:23:2444°NE20:26:4110°ESEvisible
15 Dec-0.621:58:0010°WSW22:00:1817°SW22:02:3610°Svisible
16 Dec-3.204:29:2010°SW04:32:4364°SE04:36:0410°NEvisible
16 Dec-1.421:08:4010°W21:11:3827°SW21:14:3710°SSEvisible
17 Dec-1.803:41:0110°SSW03:44:0933°SE03:47:1510°ENEvisible
17 Dec-2.620:19:4310°WNW20:23:0248°SW20:26:2310°SEvisible
18 Dec-0.902:52:5610°SSW02:55:3020°SE02:58:0510°Evisible
18 Dec-3.004:29:1310°WSW04:32:1832°NW04:35:2010°NNEvisible
18 Dec-0.121:10:2410°SW21:11:3811°SSW21:12:5210°Svisible
19 Dec-0.302:05:1110°S02:06:4713°SSE02:08:2210°ESEvisible
19 Dec-3.903:40:2710°SW03:43:5169°NW03:47:1110°NEvisible
19 Dec-0.520:20:2810°W20:22:5318°SW20:25:1910°Svisible
20 Dec-2.802:51:5710°SW02:57:2620°ENE02:58:3910°ENEvisible


Passes from Sydney (AEDST)

13 Dec-0.100:20:2410°S00:20:2410°S00:20:2910°Svisible
13 Dec-0.523:32:0712°SSE23:32:0712°SSE23:32:3510°SSEvisible
14 Dec-0.304:23:0110°S04:24:2712°SSE04:25:5410°SEvisible
14 Dec-2.121:02:1110°N21:08:26ESE21:03:4517°NNEvisible
14 Dec-2.022:38:0610°WNW22:41:1433°SW22:44:2410°SSEvisible
15 Dec-3.221:49:1510°WNW21:52:3861°SW21:56:0310°SEvisible
15 Dec0.023:29:4810°SSW23:29:5710°SSW23:30:0610°SSWvisible
16 Dec-1.304:21:3010°SSW04:24:2626°SE04:27:2110°Evisible
16 Dec-3.821:00:4210°NW21:04:0567°NE21:07:3010°SEvisible
16 Dec-0.422:39:0710°WSW22:41:0815°SSW22:43:0910°Svisible
17 Dec-0.503:33:2310°SSW03:35:4317°SSE03:38:0110°ESEvisible
17 Dec-1.021:49:3710°W21:52:2222°SW21:55:0810°SSEvisible
18 Dec-0.102:45:4110°S02:46:5411°SSE02:48:0710°SEvisible
18 Dec-3.704:20:4210°SW04:24:0780°SE04:27:3010°NEvisible
18 Dec-1.921:00:2910°WNW21:03:4036°SW21:06:5310°SSEvisible
19 Dec-2.403:32:1510°SSW03:35:3141°SE03:38:4410°ENEvisible
19 Dec-2.005:09:5710°W05:11:5715°NW05:13:5610°NNWvisible
19 Dec-0.121:51:2910°SW21:52:1811°SSW21:53:0910°SSWvisible
20 Dec-1.402:43:5710°SSW02:46:4924°SE02:49:3910°Evisible
20 Dec-2.904:20:3310°WSW04:23:3228°NW04:26:2710°Nvisible
20 Dec-0.521:01:1810°WSW21:03:2716°SSW21:05:3710°Svisible
21 Dec-0.501:55:5010°S01:56:5914°S01:56:5914°Svisible


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 planet or missing it completely. As always, 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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Wednesday, December 11, 2019

 

Geminid Meteor Shower 13-15 December 2019

The northern horizon at 4:00 am ACDST as seen from Adelaide on Sunday December 15. The Geminid radiant is marked with a starburst. Similar views will be seen elsewhere in Australia at  a similar latitude and the equivalent local time. (click to embiggen).The northern horizon at 3:00 am AEST as seen from Brisbane on Sunday December 15. The Geminid radiant is marked with a starburst. Similar views will be seen elsewhere in Australia at  a similar latitude and the equivalent local time. (click to embiggen).

The Geminids are unusual meteor shower in that their parent body is 3200 Phaethon, an asteroid, rather than a comet. It is speculated though that Phaeton is actually a "gassed out" comet, and so the debris that makes up the Geminids may still be cometary particles, but is more likely broken rock fragments from its close approach to the sun.

The Geminids are usually a fairly reliable meteor shower however this year moonlight from the nearly full Moon nearly on top of the radiant  will significantly interfere.

Despite the Geminids having a broad peak and will show good activity well before and after the peak, and on the day before and after. The peak is December 14, between 02h and 23 h UT. That is 13:00pm AEDST December 14 to 9:00 AEDST 15th in Australia.  As the Moon is almost on top of the radiant there will be poor rates but the best viewing will be from around 2-3 am AEDST (1-2 am AEST) on the morning of the 15th in Australia. As the radiant doesn't rise until just before midnight (daylight saving time) in most of Australia, so you will still have to disturb your sleep for this one.

Northern Australians should see a meteor every 4 to 5  minutes under dark skies in the early morning of the 15th between 1:00 am and 4:00 am local daylight saving time.

It is best if you can find some  object to obscure the Moon so your night vision is not too compromised by the brightness.

You can find predictions for your local site at the meteor flux estimator (choose 4 Geminids and date 14-15 December, don't forget to change the date to 2019). I have also made a table for major cities below.

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 Geminids Live page.

At 1.00 am in the morning AEDST (midnight, AEST) Castor (alpha Geminorum) is about two hand-spans above the horizon and 10 hand-spans to the right of due north. Pollux, the other twin, is less than a hand-span to the right again. The radiant is just below Pollux.

When you get up, allow at least 5 minutes for your eyes to adjust and become dark adapted (even if you have stumbled out of bed in the dark, here's some hints on dark adaption of your eyes so you can see meteors better). With the Full Moon almost on top of the radiant this makes dark adaptation very difficult. Again, it is best if you can find some  object like a tree of a post to obscure the Moon so your night vision is not too compromised by the brightness. If the object is a wall this cuts oiut a chunk of the sky so you will see fewer meteors.

Be patient, it may be several minutes before you are rewarded with you first meteor, then a couple will come along in quick succession (a meteor every 4 to 5 minutes is an average, they won't turn up like a ticking clock but more or less randomly).

Predicted meteor rates for selected towns

TownMorning December 14 Morning December 15Morning December 16
Adelaide5 meteors/hr12 meteors/hr3 meteors/hr
Brisbane5 meteors/hr16 meteors/hr4 meteors/hr
Darwin8 meteors/hr21 meteors/hr4 meteors/hr
Perth6 meteors/hr11 meteors/hr3 meteors/hr
Melbourne5 meteors/hr15meteors/hr3 meteors/hr
Hobart4 meteors/hr10 meteors/hr5 meteors/hr

Choose a viewing spot where you can see a large swathe of sky without trees or buildings getting in the way (except to block the Moon), 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 insalubrious park for example). While the radiant is where the meteors appear to originate from, most of the meteors will be seen away from the radiant, so don't fixate on the radiant, but keep your eye on a broad swath of sky roughly centred just above the radiant (as the radiant doesn't rise very high, looking exactly at the radiant will mean you miss some higher up).

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. Despite it being summer, make sure you have a jumper or something as the night can still get cold.

Guides to taking meteor photos are here and here.

As well, Orion and the Hyades will be visible. So it will be a quite nice morning for sky watching. Keep an eye out for satellites! There may be an ISS pass on the mroning of the 15th from your location.

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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Betelgeuse Fades

Evening sky at 22:10 ACDST on Saturday December 14 (90 minutes after sunset), Orion is readily visible. Betelgeuse is the bright red star below the "saucepan" of Orion.

Betelgeuse is a red giant star which forms a distinctive part of the Constellation of Orion the Hunter.

While familiar to almost all casual observers of the night sky, not may people know it is a variable star, with small fluctuations in brightness not visible to the casual observer.


A 9 year light curve of Betelgeuse from the light curve generator at the AAVSO.  It's a bit messy because of all the observations , but if you pick out the yellow line you can see the recent dip in brightness that has everyone excited.

 The variability of Betelgeuse is complex, with a
dominant period of 420 days, superimposed on a long period of 5-6 years and a shorter term variability of around 180 days. The 420 day variability was likely observed by Indigenous Australians and incorporated into their sky stories.

However now it has been reported that Betelgeuse has dimmed substantially, (see curve above) to a 25 year low (even though it is still bright to us). It is well worth keeping an eye on it, to see if it dims further.

What the dimming means is not clear. It is thought that  Betelgeuse's  variability is due to the star expanding and contracting in size, with dimming due to contraction. The unusual dip in brightness may be due to its' multiple cycles lining up, or possibly dust being brought up to the surface.

Betelgeuse may be getting a bit more attention as we expect it to go Supernova, but we don't expect that to happen for tousands, if not millions, of years from now.

At the moment getting a good fix on Betelgeuse's brightness will be a bit difficult, as the nealy full moon will make determining its brightness harder, but by the week end there should be enough time before the moon rise to get a good feel for it. Achernar (magnitude 0.45), Alpha Crucis  (magnitude 0.61) and Beta Centauri (magnitude 0.55) and the red giant star Aldebaran (magnitude 0.85) are good comparison  stars. All in all  Betelgeuse will be an interesting object over the coming month.

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Tuesday, December 10, 2019

 

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

The Full Moon is Thursday December 12, the Last Quarter Moon is Thursday December 19.  Saturn is above Jupiter and Venus in the western evening skies at the beginning of the week.Venus climbs even higher in the evening twilight leaving Saturn behind.  This is the last week to see Jupiter before it disappears in the evening twilight.  Mars and Mercury visible in the morning twilight. Bright star Betelgeuse dims. Geminid meteor shower morning 15th.

The Full Moon is Thursday December 12, the Last Quarter Moon is Thursday December 19.The Moon is at perigee, when it is closest to the Earth, on the 19th.

Sky at 20:53 ACDST on Saturday December 14 (30 minutes after sunset) looking west as seen from Adelaide. Venus is above Saturn and Jupiter is just above the horizon.








Similar views will be seen elsewhere in Australia 30 minutes after sunset, click to embiggen.

Morning sky at 5:26 ACDST facing east as seen from Adelaide on Friday 13 December 30 minutes before sunrise.

Mars is low above the horizon below Spica and above Mercury. You may need binoculars to see Mercury.Mars is at its closest to the star Zubenelgenubi at this time, but you may need binoculars to see it as well.



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



Evening sky at 22:10 ACDST on Saturday December 14 (90 minutes after sunset), Orion is readily visible. Betelgeuse is the bright red star below the "saucepan" of Orion.

Betelgeuse is a red giant star which forms a distinctive part of the Constellation of Orion. It is a variable star, with small fluctuations in brightness not visible to the casual observer.

However now it has been reported that Betelgeuse has dimmed substantially, to a 25 year low (even though it is still bright to us). It is well worth keeping an eye on it, to see if it dims further. What the dimming means is not clear, but Betelgeuse will be an interesting object over the coming month.

Geminid radiant seen facing north in the southern Hemisphere at 4:00 am daylight saving time, December 15.

The Geminids are normally a fairly reliable meteor shower, with rates of about a meteor per minute at their best.

This is a poor year for Geminids, as the Full Moon is almost on top of the radiant. The radiant doesn't rise until just before midnight (daylight saving time) in most of Australia, so you will have to disturb your sleep for this one. At 1.00 am in the morning AEDST (midnight, AEST) Castor (alpha Geminorum) is about two hand-spans above the horizon and 10 hand-spans to the left of due north. Pollux, the other twin, is less than a hand-span to the left again. The radiant is just below Castor. Australians should see a meteor every 12 minutes under dark skies in the early morning of the 15th, between 2:00 am and 4:00 am.


Venus is higher above the western horizon in the late evening twilight. Venus is now readily seen up to 90 minutes after sunset.Venus leaves Saturn behind over the week.

Mercury is low in  the twilight but is still difficult to see.

Jupiter   is barely visible low in the western twilight below Saturn and Venus. Jupiter sets around 45 minutes after sunset. This is the final week to see Jupiter before it disappears in the twilight glow.

Mars is visible in the morning twilight  above Mercury. It is closest to the second brightest star in Libra, Zubenelgenubi, on the 13th.

Saturn  is above Jupiter and below Venus and near the "handle" of the "teapot of Sagittarius.


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




Star Map via Virtual sky. Use your mouse to scroll around and press 8 when your pointer is in the map to set to current time.

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, December 03, 2019

 

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

The Full Moon is Thursday December 12.  Saturn is above Jupiter and Venus in the western evening skies at the beginning of the week.Venus climbs even higher in the evening twilight closing in on Saturn and is at its closest on the 11th.  Jupiter is difficult to see low in the evening twilight.  Mars and Mercury visible in the morning twilight. Variable star Mira still bright.

The Full Moon is Thursday December 12. 

Sky at 21:28 ACDST on Wednesday December 12 (60 minutes after sunset) looking west as seen from Adelaide. Venus and Saturn are at their closest.

The left upper insert shows the telescopic view of Jupiter at this time. The lower right insert shows the telescopic view of Saturn and the lower left is Venus at the same magnification .

Similar views will be seen elsewhere in Australia 60 minutes after sunset, click to embiggen.

Morning sky at 5:28 ACDST facing east as seen from Adelaide on Saturday 7 December 30 minutes before sunrise.

Mars is low above the horizon below Spica and above Mercury. You may need binoculars to see Mercury.



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


Cetus looking north-west at 22:04 pm ACDST on Saturday 7 December (90 minutes after sunset), Mira is indicated by the circle.

Mira (omicron ceti), a star in the constellation of Cetus the whale, is a long period pulsating red giant and changes brightness from below naked eye visibility to a peak of round magnitude 2 (roughly as bright as beta Crucis in the Southern Cross) in around 330 days.

Mira was predicted to peak with maximum of 3.4 around 24 October. However, many observers are still reporting it as bright(ish). Mira may be seen above the northern horizon from around 90 minutes after sunset. Mira is currently visible to the unaided eye and may noticeably fade over December. Similar views will be seen elsewhere in Australia 90 minutes after sunset, click to embiggen.


Venus is higher above the western horizon in the late evening twilight. Venus is now readily seen up to 90 minutes after sunset.Venus comes closer to Saturn over the week as it leaves Jupiter behind.Venus and Saturn are at their closest on the 11th.

Mercury is low in  the twilight but is still difficult to see.

Jupiter   is still visible low in the western twilight below Venus. Jupiter sets around 60 minutes after sunset. This is the last week to easily see Jupiter before it disapears in the twilight glow.

Mars is visible in the morning twilight  above Mercury

Saturn  is above Jupiter and Venus and near the "handle" of the "teapot of Sagittarius. Venus comes closer to Saturn over the week and the pair are at their closest on the 11th.


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




Star Map via Virtual sky. Use your mouse to scroll around and press 8 when your pointer is in the map to set to current time.

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/

Labels:


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