Astroblog

The Last Quarter Moon is Monday April 21.  Jupiter and Mars are visible in the evening sky. Jupiter forms a line with the stars Aldebaran and Elnath and sets mid evening. Mars is high in the early evening sky forming a line with the bright stars Castor and Pollux. Look for the constellation Corona Borealis in the morning skies, the blaze star T Coronae Borealis (TCrB) may go Nova eventually.  Saturn, Venus and Mercury are visible in the morning twilight. Mercury is close to Neptune on the 17th and 18th and  at its highest on the 22nd.

The Last Quarter Moon is Monday April 21. 

Saturn is visible in the twilight forming a triangle with Mercury and Venus. Mercury is close to Uranus

The inset is the binocular view of Mercury and Uranus  at this time.  (click to embiggen).

Similar views will be seen from the rest of Australia at roughly the equivalent local time (60 minutes before sunrise). 

 

Eastern twilight sky on the morning of Thursday, April 24 as seen from Adelaide at 05:51 ACST (60 minutes before sunrise, click to embiggen).

Saturn is visible in the twilight close to Venus with Mercury below. The waning moon is above making a nice lineup.

The inset is the telescope view of Venus at this time.  (click to embiggen).

 

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time (60 minutes before sunrise). 

 

If you look to the North at astronomical twilight (90 minutes before sunrise), you will see a prominent bright white star, Vega, if you look northwest you will see a dainty circlet of stars. Corona Borealis, the northern crown. The blaze star T CrB is located on the right-hand side to the circlet, where the line of stars turns down, there are no other bright stars in the region, so when it erupts it will be easily visible. Viewing tips at my T CrB post.

Similar views will be seen from the rest of Australia at roughly the equivalent local time (90 minutes before sunrise).

 

North-western sky on Saturday, April 19 as seen from Adelaide at 19:11 ACST (90 minutes after sunset, click to embiggen). Jupiter is in the north-west forming a line with the stars Aldebaran and Elnath; Mars forms a line with Castor and Pollux.

 

The insets are the telescope views of  Jupiter and Mars at this time.  (click to embiggen).   

 

 

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time (90 minutes after sunset). 

 

Whole sky on Saturday, Saturday, April 19 as seen from Adelaide at 19:11 ACST, 90 minutes after sunset (click to embiggen).

Jupiter is in the north-west.  Mars is in the north. 

 

Orion  the hunter is lowering in the north-west.

 

The Southern Cross is rising in the Southern sky.  The moon is waxing and the fainter clusters and nebula are becoming harder to see.      

 

 Elsewhere in Australia will see a similar view at the equivalent time (90 minutes after sunset).

 

 

Mercury climbs higher in the morning twilight. Mercury is close to Neptune on the 17th and 18th and  at its highest on the 22nd.

Venus climbs higher in the morning twilight. It forms a pair with Saturn.

Mars is high in the evening sky. Mars forms a line with the bright stars Castor and Pollux.

Jupiter is sinking in the the north-western evening sky when the sky is fully dark. Jupiter forms a line with the stars Aldebaran and Elnath. 

Saturn is rising in the morning the twilight. It forms a pair with Venus.

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.


 

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

# posted by Ian Musgrave @ 6:41 pm 0 comments

The Full Moon is Sunday April 13.  Jupiter and Mars are visible in the evening sky. Jupiter forms a line with the stars Aldebaran and Elnath and sets in the late evening. Mars is high in the early evening sky forming a line with the bright stars Castor and Pollux. Look for the constellation Corona Borealis in the morning skies, the blaze star T Coronae Borealis (TCrB) may go Nova eventually.  Saturn, Venus and Mercury are visible in the morning twilight. Mercury is close to Saturn between the 10th and 12th forming a triangle with Venus.

The Full Moon is Sunday April 13. Apogee, when the Moon is furthest from the earth, is on the 14th.

Saturn is visible in the twilight forming a triangle with Mercury and Venus. 

The inset is the telescope view of Venus at this time.  (click to embiggen).

If you look to the North-west at astronomical twilight (90 minutes before sunrise), you will see a prominent bright orange star, Arcturus, if you look northwardst you will see a dainty circlet of stars. Corona Borealis, the northern crown. The blaze star T CrB is located on the right-hand side to the circlet, where the line of stars turns down, there are no other bright stars in the region, so when it erupts it will be easily visible. Viewing tips at my T CrB post.

Similar views will be seen from the rest of Australia at roughly the equivalent local time (90 minutes before sunrise).

 

North-western sky on Saturday, April 12 as seen from Adelaide at 19:20 ACST (90 minutes after sunset, click to embiggen). Jupiter is in the north-west forming a line with the stars Aldebaran and Elnath; Mars forms a line with Castor and Pollux.

 

The insets are the telescope views of  Jupiter and Mars at this time.  (click to embiggen).   

 

 

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time (90 minutes after sunset). 

 

Whole sky on Saturday, Saturday, April 12 as seen from Adelaide at 19:11 ACST, 90 minutes after sunset (click to embiggen).

Jupiter is in the north-west.  Mars is in the north. 

 

Orion  the hunter is lowering in the north-west.

 

The Southern Cross is rising in the Southern sky.  The moon is waxing and the fainter clusters and nebula are becoming harder to see.      

 

 Elsewhere in Australia will see a similar view at the equivalent time (90 minutes after sunset).

 

 

Mercury climbs higher in the morning twilight. On the 10th to the 12th Mercury is close to Saturn forming a triangle with Venus.

Venus climbs higher in the morning twilight. It is near to Mercury and Saturn

Mars is high in the evening sky. Mars was at opposition, when it is biggest and brightest as seen from Earth, on January the 16th. Mars forms a line with the bright stars Castor and Pollux.

Jupiter is sinking in the the north-western evening sky when the sky is fully dark. Jupiter forms a line with the stars Aldebaran and Elnath. 

Saturn is rising in the morning the twilight. On the 10th to the 12th Mercury is close to Saturn forming a triangle with Venus.

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.


 

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

# posted by Ian Musgrave @ 9:03 pm 0 comments

The Lunar X and V (indicated) as visible in telescopic views. Click to embiggen for a clearer view.	Western evening sky on Saturday April 5 as seen from Adelaide at 23:17 ACDST	Western evening sky on Saturday April 55 as seen from Brisbane at 22:43 AEST
Sunrise on the Moon: Moon at 20:00 ACDST, the Lunar V is just visible.	Sunrise on the Moon: Moon at 21:00 ACDST, the Lunar V is becoming visible. Some crater walls are beginning to light up	Sunrise on the Moon: Moon at 21:00 ACDST, the Lunar V is  visible. Some crater walls are lighting up and the frist hints of the Lunar X are there

The Lunar X (also known as the Werner X) and the Lunar V will be visible this Saturday as the moon reaches First Quarter. The Lunar X is a chiaroscuro effect in which strong contrasts of light and shadow create the appearance of a letter 'X' on the rim of the Lunar craters Blanchinus, La Caille and Purbach and a letter V from the rim of the crater Ukert, along with several smaller craters. 

The X and V are seen at first quarter, visible on the lunar surface for about 4 hours. However, the Moon is not always above the horizon from a given vantage point when this happens. This month is okay for Australian observers, with the Moon low to the horizon in the eastern sates, and reasonably high on the west coast.

Lunar X occurs on Saturday April 5, 12:43 UT, 23:43 AEDST,  22:43 AEST, 23:17 ACDST, 22:17 ACST, 20:43 AWST). This is later than official first Quarter which occurs at 12:45 ACDST.

This is a telescope (and maybe good binoculars) only event. For the west coast the start of the Lunar X occurs with the Moon being 25° above the horizon, central states see it at 11° above the horizon, and for the east coast at 6° above the horizon.

Upcoming Lunar X' s are shown below:

Dates and time Lunar X and V are visible. Typically visible from about 4hours from the starting time, times in colour are daylight saving times.

If you are setting up to see the Lunar X, why not start early so you can watch sunrise on the Moon? You can watch the sides of crater walls light up as hours progressStarting from nautical twilight, an hour after sunset, image the Moon through binoculars of a telescope every hour until around moon set and you can see the walls of the Lunar V light up, then the walls of the X. 

Also if you are setting up early, catch the reappearance of Iota Geminorum from occultation by the Moon.

Iota Geminorum about to be occulted by the Moon as seen from Brisbane at 19:09 AEST	Iota Geminorum emerging from behind the Moon as seen from Brisbane at 20:09 AEST

Labels: Lunar X, Moon, telescope

# posted by Ian Musgrave @ 12:14 am 2 comments

The First Quarter Moon is Saturday April 5.  The Lunar X will be visible then. daylight savings ends on the 6th. Jupiter and Mars are visible in the evening sky. Jupiter is past opposition and is visible all evening long, forming a line with the stars Aldebaran and Elnath. The Moon joins the line-up with Jupiter on the 3rd. Mars is high in the early evening sky and is close to the Moon on the 5th. Look for the constellation Corona Borealis in the morning skies, the blaze star T Coronae Borealis (TCrB) may go Nova eventually.  Saturn, Venus and Mercury are visible low in the morning twilight.

The First Quarter Moon is Saturday April 5. The Lunar X will be visible then (see table below for time the Lunar X starts to be visible add one hour for daylight savings time). daylight savings ends on the 6th.

Saturn is visible low in the twilight forming a line with Mercury and Venus. You may need binoculars to see Mercury. 

The inset is the telescope view of Venus at this time.  (click to embiggen).

If you look to the North at astronomical twilight (90 minutes before sunrise), you will see a prominent bright orange star, Arcturus, if you look downwards and to the right you will see a dainty circlet of stars. Corona Borealis, the northern crown. The blaze star T CrB is located on the right-hand side to the circlet, where the line of stars turns down, there are no other bright stars in the region, so when it erupts it will be easily visible. Viewing tips at my T CrB post.

North-western evening sky on Thursday, April 3 as seen from Adelaide at 20:32 ACDST (90 minutes after sunset), Jupiter is in the north-west forming a line with the stars Aldebaran and Elnath and the crescent Moon.

The inset is the telescope view of  Jupiter at this time.  (click to embiggen). 

 

 Similar views will be seen from the rest of Australia at roughly the equivalent local time (90 minutes after sunset).

Northern sky on Saturday, April 5 as seen from Adelaide at 20:29 ACDST (90 minutes after sunset, click to embiggen). Mars forms a line with Castor and Pollux. The first quarter Moon forms a triangle with Mars and Pollux. There is also an occultation of Iota Geminorum.

 

The insets are (clockwise) the telescope view of  Mars at this time.  The View of the moon as Iota Geminorum reappears at 20:25 ACDST and the appearance of the Lunar X at 23:00 ACDST  (click to embiggen).   

 

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time (90 minutes after sunset). 

 

Whole sky on Saturday, Saturday, April 5 as seen from Adelaide at 20:38 ACDST, 90 minutes after sunset (click to embiggen).

Jupiter is in the north-west.  Mars is in the north. 

 

Orion  the hunter is lowering in the north-west.

 

The Southern Cross is rising in the Southern sky.  The moon is waxing and the fainter clusters and nebula are becoming harder to see.     

 

 Elsewhere in Australia will see a similar view at the equivalent time (90 minutes after sunset).

 

 

Mercury returns to the morning twilight.

Venus returns to the morning twilight. 

Mars is high in the evening sky. Mars was at opposition, when it is biggest and brightest as seen from Earth, on January the 16th. Mars is close to the first quarter Moon on the 5th.

Jupiter is high in the the north-western evening sky when the sky is fully dark. Jupiter forms a line with the stars Aldebaran and Elnath. The Moon joins the line-up Jupiter on the 3rd.

Saturn is low in the morning the twilight. 

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.


 

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

# posted by Ian Musgrave @ 11:14 pm 0 comments

Sky chart facing north west on Sunday, March 30 as seen from Adelaide at 06:02 ACST (90 minutes before sunrise, click to embiggen). The location of T CrB is shown with a circle. Similar views will be seen 90 minutes after Sunset elsewhere in Australia.	Printable black and White Sky chart facing north west on Sunday, March 30 as seen from Adelaide at 06:o2 ACST (90 minutes before sunrise, click to embiggen and print). The location of T CrB is shown with a dark square The field of view of 10x50 binoculars is shown with circle. Similar views will be seen 90 minutes after Sunset elsewhere in Australia.

Some recent postings about the "Blaze Star" T Coronae Borealis (T Crb) are suggesting it might go Nova Real Soon Now. It hasn't, but spectral indications suggest it may be ready to go "soonish" (where soonish is anywhere between now and November 2025).

Although you need to be up in the early hours of the morning to see it, T CrB goes nova roughly every 80 years, where it flaers from being invisible to the unaided eye to brighter than the brightest star in its constellation (~ magnitude 2).  So its worth while  keeping an eye out for this rare event.

Labels: astrophotography, citizen science, nova, T CrB

# posted by Ian Musgrave @ 2:14 pm 0 comments

The New Moon is Saturday March 29. Jupiter and Mars are visible in the evening sky. Jupiter is past opposition and is visible all evening long, forming a line with the stars Aldebaran and Elnath. The Moon joins the line-up with Jupiter on the 3rd. Mars is high in the early evening sky. Look for the constellation Corona Borealis in the morning skies, the blaze star T Coronae Borealis (TCrB) may go Nova eventually.  The Crescent Moon is near Saturn in the morning twilight on the 28th.

The New Moon is Saturday March 29. The moon is at perigee, when it is closet to the Earth, on the 30th.

Saturn is visible low in the twilight. Below the thin crescent moon.

If you look to the North at astronomical twilight (90 minutes before sunrise), you will see a prominent bright orange star, Arcturus, if you look downwards and to the right you will see a dainty circlet of stars. Corona Borealis, the northern crown. The blaze star T CrB is located on the right-hand side to the circlet, where the line of stars turns down, there are no other bright stars in the region, so when it erupts it will be easily visible. Viewing tips at my T CrB post.

North-western evening sky on Thursday, April 3 as seen from Adelaide at 20:32 ACDST (90 minutes after sunset), Jupiter is in the north-west forming a line with the stars Aldebaran and Elnath and the crescent Moon.

The inset is the telescope view of  Jupiter at this time.  (click to embiggen). 

 

 Similar views will be seen from the rest of Australia at roughly the equivalent local time (90 minutes after sunset).

Northern sky on Saturday, March 29 as seen from Adelaide at 20:38 ACDST (90 minutes after sunset, click to embiggen). Mars forms a triangle with Castor and Pollux. 

 

The inset is the telescope view of  Mars at this time.  (click to embiggen).

   

 

 

 

Similar views will be seen from the rest of Australia at roughly the equivalent local time (90 minutes after sunset). 

Whole sky on Saturday, Saturday, March 29 as seen from Adelaide at 20:38 ACDST, 90 minutes after sunset (click to embiggen).

Jupiter is in the north-west.  Mars is in the north. 

 

Orion  the hunter is high in the north-west.

 

The Southern Cross is rising in the Southern sky.  The moon is new and the fainter clusters and nebula are easier to see.     

 

 Elsewhere in Australia will see a similar view at the equivalent time (90 minutes after sunset).

 

 

Mercury is lost in the evening twilight.

Venus is lost in the twilight. 

Mars is high in the evening sky. Mars was at opposition, when it is biggest and brightest as seen from Earth, on January the 16th. 

Jupiter is high in the the north-western evening sky when the sky is fully dark. Jupiter forms a line with the stars Aldebaran and Elnath. The Moon joins the line-up Jupiter on the 3rd.

Saturn returns to the morning the twilight. It is near the crescent Moon on the 28th.

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.


 

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

# posted by Ian Musgrave @ 11:48 pm 0 comments

Sky chart facing north on Saturday, March 22 as seen from Adelaide at 05:56 ACST (90 minutes before sunrise, click to embiggen). The location of T CrB is shown with a circle. Similar views will be seen 90 minutes after Sunset elsewhere in Australia.	Sky chart facing north on Saturday, March 22 as seen from Adelaide at 05:56 (90 minutes before sunrise, click to embiggen). Constellation names and lines are shown for clarity.

My image of Corona Borealis taken on 10 August with my Samsung S24 in astrophography mode at 5x zoom. Stars down to magnitude 7.5 are visible. The approximate location of T CrB is shown with a star above Ɛ CrB.	AAVSO chart of Corona Borealis showing the magnitude of surrounding stars. The decimal points have been omitted eg 22 is 2.2, 89 is 8.9

T Coronae borealis (T CrB) did not go Nova Last September as predicted. However, Thuringian State Observatory noticed the emission lines in the spectrum of T CrB have risen sharply, indicating a greatly increased accretion rate, and possibly an outburst is coming soon. See also https://www.astronomerstelegram.org/?read=17041

Unfortunately, Corona Borealis is in the morning sky now, so you have to get up at dark o'clock to see it.

If you look to the North in the morning at astronomical twilight (90 minutes before sunrise), you will see a prominent bright orange star, Arcturus (see top chart), if you look downwards and to the right you will see a dainty circlet of stars. Corona Borealis, the northern crown.

While pretty in its own right, it houses a most unusual star, T Coronae borealis (T CrB), also known as the blaze star. T CrB is a recurrent nova, a binary system where gas from a red giant star accretes on a white dwarf companion. Eventually the gas builds up to a density where a nuclear explosion occurs and this is seen as  a nova. 

A recurrent nova is one where there is a (semi) regular patter of repeated outbursts. T CrB seems to erupt every 80 years, with the last in 1946. Recent patterns of brightening and dimming look like the pre outburst phase of the 1946 eruption. It was predicted that T CrB may go nova between August and the end of September 2024. That didn't happen, but the new spectral changes may herald the long awaited outburts

When that happens, T CrB will rapidly rise to from its current magnitude 10 (well below eye or binocular visibility)  around magnitude 2 about the same brightness as Alphecca, 𝛂 Coronae Borealis (see bottom left-hand panel), the brightest star in the constellation. It will only remain above unaided eye visibility for a week or so. 

T CrB is located on the right-hand side to the circlet, just above Ɛ CrB (see bottom left-hand panel) where the line of stars turn down, there are no other bright stars in the region, so when it erupts it will be easily visible.

The challenge:  

Take an image of Corona Borealis every clear morning during March-April awaiting the eruption. You will need a stack of ~ 10 images at high ISO of around 1 second duration, then stacked in appropriate software to pick up the faint stars. It would be best if you zoomed in so that Corona Borealis occupies most of the camera field (with a bit of space on the right-hand side so you don’t miss out on T CrB. That way hopefully you will catch not only the eruption, but the fade as well, doing a bit of backyard astrophysics. 

Be patient, after a few night astrophotography you will become familiar with the stars and will easily see when T CrB erupts. 

You can also follow the T CRB Nova Watch on Space weather (in the the righthand panel). Currently magnitude 10.

Labels: astrophotography, citizen science, nova, T CrB

# posted by Ian Musgrave @ 6:12 pm 0 comments