Astroblog

 Evening sky showing the track of comet C/2022 E3 from Monday February 6 to Tuesday February 14 as seen from Adelaide at 21:56 ACDST, 90 minutes after sunset (click to embiggen). The comet is easily visible in binoculars and can be located by sweeping up from the bright star Capella above the northern horizon towards Mars and the star Aldebaran. For more detailed carts and spotters maps see my C/2022 E3 page.

 

The February edition of Southern Skywatch is now up. 

This month the planetary action is largely in the evening skies, with Venus. Jupiter and Mars prominent and bright, Saturn is lost in the twilight and Mercury begins to leave morning sky. February is also when the long-awaited comet C/2022 E3 enters the evening sky.

February 4; apogee Moon. February 6; Full Moon. February 5-6; comet C/2022 E3 becomes visible in Australian skies. February 14; Last Quarter Moon. February 19; the thin crescent moon near Mercury in the morning sky. February 19; Moon at perigee. February 20; New Moon. February 22; the crescent Moon is very close to Venus in the twilight. February 22-23; Jupiter, the crescent Moon and Venus make a nice line-up. February 26; the crescent Moon is close to Jupiter. February 29; First Quarter Moon. February 28; the Moon is close to Mars, Venus and Jupiter close. 

Mercury begins to fall back towards the eastern horizon sky this month. On the 19th the thin crescent moon is less than 4° above Mercury. You will need a level, unobstructed horizon to see the pair at their best. You may need binoculars to clearly see the pair. On the 1st Mercury is just one and a half hand-spans from from the eastern horizon an hour before sunrise. On the 15th Mercury is just under one and a half hand-spans from from the eastern horizon an hour before sunrise. By the 28th Mercury is just one and a half hand-spans from from the eastern horizon half an hour before sunrise.

 Venus climbs higher in the evening sky this month; the low angle of the ecliptic means it never gets really high although it is prominent at nautical twilight by the end of the month Venus has three close encounters this month. On the 15th Venus and Neptune are just 10 arc-minutes apart, but this will be almost impossible to observe. On the 22nd Venus will be just 1° from the crescent moon, making a fine binocular sight. Venus currently looks like a gibbous Moon. Venus and Jupiter have been approaching each other all month, and on the 28th are just 2° apart and will be even closer in March, they will make a fine binocular pair but telescopic observation will be tricky.  

Mars is well past opposition this Month but is still prominent, making a triangle with Aldebaran and the Pleiades. As the month progress mars fades more as it moves down the “horns” of Taurus the Bull. By the end of the Month Mars forms a triangle with Beta and Zeta Taurii (the tips of the horns). Mars is shrinking in telescopic view but is still a worthwhile telescopic object this month. On the 28th Mars is around 3° from the waxing moon (very obvious as the brightest object near the moon), mid power binocular fields will fit the pair in.  

Jupiter is lowering in the north-western evening sky. It is a difficult telescopic object best captured just before astronomical twilight early in the month. On the 22nd and the 23rd Jupiter the crescent Moon, and Venus make a pleasing line up in the twilight. Venus and Jupiter have been approaching each other all month, and on the 28th are just 2° apart and will be even closer in March.  

Saturn is lost in the twilight and will enter the morning skies mid-March.

Labels: southern skywatch

The Full Moon is Monday February 6 (apogee mini moon). Jupiter is easy to see as brightest object in the western evening sky aside from the Moon. Jupiter is sinking towards the horizon coming closer to Venus which is challenging Jupiter for brightest evening object as it climbs out to the twilight. Bright Mars, the red star Aldebaran and the Pleiades cluster form a triangle. Comet C/2022 E3 enters the evening sky and is visible in binoculars. 

The Full Moon is Monday February 6. The Moon is at Apogee February 4.

Morning sky on Saturday, February 4  as seen from Adelaide at 05:36 ACDST, (60 minutes before sunrise, click to embiggen). Mercury is below the Scorpius.

   

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

 

Evening sky on Saturday, February 4 as seen from Adelaide at 21:03 ACDST, (45 minutes after sunset, click to embiggen). Venus is low above the horizon with Jupiter above.You will need a low, unobstructed horizon to see Venus at its best.

   

Similar views will be seen from the rest of Australia at the equivalent local time (45 minutes after sunset). 

 Evening sky on Saturday February 4 as seen from Adelaide at 21:56 ACDST, 90 minutes after sunset (click to embiggen). Mars, the red star Aldebaran and and the Pleiades cluster form a triangle. 

Jupiter is seen low in the west

 

Mars was at opposition, when was at its biggest and brightest as seen from Earth, on December the 8th, but is still an excellent sight. The insets are the telescopic views of Mars and Jupiter at this time.

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

 

Labels: weekly sky

Track of comet C/2022 as seen from Adelaide at astronomical twilight (an hour after sunset) when the sky is fully dark (21:53 ACDST). The positions of the comet from 6-14 February are shown. Click to embiggen. Similar views will be seen elsewhere in Australia at astronomical twilight. Simulated in Stellarium.	Location of comet C/2022 on 6 February 20:04 as seen from Brisbane at astronomical twilight (an hour after sunset) when the sky is fully dark . Click to embiggen. Simulated in Stellarium.	Location of comet C/2022 on 6 February 21:32 as seen from Melbourne at astronomical twilight (an hour after sunset) when the sky is fully dark . Click to embiggen. Simulated in Stellarium.
Black and white guide map suitable for printing (use with a red light torch to keep your night vision intact). Click to embiggen and print.	Black and white binocular spotters map with guide stars identified, suitable for printing (use with a red light torch to keep your night vision intact). Click to embiggen and print.	Black and white binocular map for the night of February 6 with guide stars identified, suitable for printing (use with a red light torch to keep your night vision intact). Click to embiggen and print. The circle is the approximate field of view of 10x50 binoculars.

You have probably heard of Comet C/2022 E3 (ZTF), described some what breathlessly in some media outlets as "a rare green comet last seen by the neanderthals". The wording is a bit unclear, but it is not rare for a comet to be green, as comets (variously described as "dirty iceballs" of "Icy dirt balls") come close to the sun their ices start to vaporise, comets not only have water ice but also organic ices such as ethanol and methane.

The ultra violet light from the sun causes these molecule to break down and form dicarbon, two carbon atoms bind together, which fluoresces green in ultraviolet light. Of course this is rather dim, and can usually only be picked up by long exposure images, you are not likely to see any colour with the unaided eye, even in telescopes.

The comet appears to have come from the Oort Cloud, and last passed earth around 50,000 years ago, if any curious proto-humans had looked at the patch of sky were the comet was all those eons ago, it is unlikely that they would have taken notice of the faint fuzzy patch. Whether C/2022 E3 (ZTF) will return to the Oort cloud is still unclear. ZTF stands for Zwicky Transient Facility, which normally looks for things like supernova.

Currently people in the norther hemisphere are reporting that it is just unaided eye visible. With binoculars its looking like a fuzzy blob with a central condensation and the hint of a tail. While you may have seen some stunning images of the dust tail and ion tail, these are telescopic images with extended exposure times, so what you see in a telescope is likely to be much less dramatic. 

Black and white binocular map for the night of February 6 with guide stars identified. Almaaz in the stellarium map is epsilon (ε) Aurigae on the black and white map. The circle is the approximate field of view of 10x50 binoculars.	Approximate binocular sky view or the night of February 6simulated in stellarium for a comparison to the black and white map to give you a feel fro how they translate to the sky. Click to embiggen

Northern Australia has the best views with Places like Darwin and Cairns potentially seeing the comet from the 3rd, Brisbane, Perth and Sydney from the 5th and Adelaide and Melbourne have to wait for the 6th.

While the comet is theoretically unaided eye visible under dark sky conditions when it enters Australian skies, the fact that it will be low in the horizon murk and with the full Moon on the horizon (6th, waxing Moon earlier) will likely make it a binocular only comet.

Over the coming days conditions get better as the moon leaves the evening skies and the comet gets higher, but it is also fading, so there is a good chance that it will remain binocular only. This does not that it will be unworthy of following, comet C/2021 A1 Leonard was basically binocular only, but was a lovely little comet with good binocular features and a significant out burst that produced a nice tail than spanned almost an entire binocular field. So do not despair and have a look.

We are also lucky that that we have good guidepost stars and that the comet will be one of the brightest objects in most of the fields aside from the guide stars. 

On the 5th the comet is a binocular field below Capella, alpha (⍺) Aurigae, the brightest object almost due north above the northern horizon (see charts above). On the 6th it is within a binocular field of Capella, close to the brightish star epsilon (ε) Aurigae (Almaaz in Stellarium). It should be obvious as a fuzzy blob with a central condensation.

As always let your eyes dark adapt for around 5 minute before searching, a bit longer if you have been looking at bright computer/TV screens. Start looking when the sky is fully dark for the best results (and hour and a half after local sunset).

In general, to find the comet sweep up from Capella in a line towards mas and Aldebaran (again, see maps above) .

On the 7th the comet is a binocular field above  epsilon (ε) Aurigae, just above a distinctive triangle of stars with epsilon (ε) Aurigae as its apex.

On the 8th it is a binocular field below iota Aurigae, then on the 9th within a binocular field above the star, in a line with Mars. On the 10th it is within a binocular field of Mars.

On the 11th it is a finger width from Mars,  and although no longer unaided eye visible, the sight of the pair together should be really nice.

The comet then continues up towards the Hyades and Aldebaran on the 14th and 15th the comet is within a binocular field of Aldebaran and should still be obvious in binoculars.

The positions for the comet from the  Minor Planet & Comet Ephemeris Service are below. It can also format the output for various astronomy programs. put C/2022 E3 in the search box (note the capitalisation).

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 C/2022 E3 (ZTF)

Perturbed ephemeris below is based on elements from MPEC 2023-BF4.

    CK22E030
Date       UT      R.A. (J2000) Decl.    Delta     r     El.    Ph.   m1     Sky Motion
            h m s                                                            "/min    P.A.
2023 01 28 000000 13 59 04.4 +73 52 24   0.325   1.139  110.5  54.1   5.6   12.73    322.9
2023 01 29 000000 12 57 41.9 +77 42 40   0.310   1.143  113.2  52.3   5.5   13.99    307.8
2023 01 30 000000 11 05 40.0 +80 09 13   0.298   1.147  115.9  50.6   5.5   15.13    280.2
2023 01 31 000000 08 44 28.4 +79 19 14   0.290   1.151  118.3  48.9   5.4   16.04    245.2
2023 02 01 000000 07 08 06.5 +75 19 56   0.285   1.155  120.2  47.5   5.4   16.60    221.5
2023 02 02 000000 06 16 27.7 +69 50 45   0.284   1.160  121.6  46.4   5.4   16.72    209.0
2023 02 03 000000 05 47 18.0 +63 50 49   0.287   1.164  122.3  45.7   5.5   16.39    202.1
2023 02 04 000000 05 29 12.6 +57 48 35   0.294   1.169  122.3  45.4   5.5   15.66    198.0
2023 02 05 000000 05 17 06.2 +51 59 46   0.304   1.174  121.7  45.6   5.6   14.63    195.3
2023 02 06 000000 05 08 31.6 +46 33 26   0.317   1.180  120.6  46.0   5.7   13.42    193.5
2023 02 07 000000 05 02 11.5 +41 34 11   0.333   1.185  119.2  46.6   5.9   12.15    192.2
2023 02 08 000000 04 57 21.7 +37 03 29   0.352   1.191  117.6  47.2   6.0   10.90    191.2
2023 02 09 000000 04 53 35.5 +33 00 42   0.372   1.197  115.8  47.9   6.1    9.72    190.4
2023 02 10 000000 04 50 35.4 +29 24 03   0.395   1.203  114.0  48.6   6.3    8.64    189.7
2023 02 11 000000 04 48 10.2 +26 11 07   0.419   1.209  112.2  49.1   6.4    7.68    189.2
2023 02 12 000000 04 46 11.8 +23 19 22   0.443   1.215  110.4  49.6   6.6    6.83    188.6
2023 02 13 000000 04 44 34.6 +20 46 15   0.469   1.222  108.7  49.9   6.7    6.08    188.1
2023 02 14 000000 04 43 14.3 +18 29 30   0.496   1.228  107.1  50.2   6.9    5.44    187.6
2023 02 15 000000 04 42 08.0 +16 26 59   0.523   1.235  105.5  50.4   7.0    4.87    187.1
2023 02 16 000000 04 41 13.1 +14 36 55   0.551   1.242  104.0  50.5   7.1    4.38    186.6
2023 02 17 000000 04 40 27.8 +12 57 42   0.580   1.249  102.5  50.6   7.3    3.95    186.0


MPEC one line format
    CK22E030  2023 01 12.7851  1.112249  1.000327  145.8156  302.5557  109.1685  20230225   7.5  4.0      C/2022 E3 (ZTF)

Labels: binocular, C/2022 E3, comet, unaided eye

Full Moon January 7, 21:18 ACDST. Apogee 8th -1d9h.	Full Moon February 6, 21:18 ACDST (FM 4 am, apogee 4th -1d9h)	Full Moon March 7, FM 23:00 ACDST
Full Moon April 6, 21:27 ACST	Full Moon May 6 03:52 ACST,  at maximum penumbral Lunar eclipse	Full Moon June 6 18:41 ACST
Full Moon July 3 18:41:00 ACST.	Full Moon August 2 5:00 ACST. Perigee 2nd 3:30pm	Full Moon August 31 02:00 ACST. Perigee, 11:30 am (best this year) also Blue Moon
Full Moon September 29 20:00 ACST,	Full Moon October 29 05:04 ACST Partial Lunar Eclipse	Full Moon November 17 21:53 ACDST
Full Moon December 27 21:18 ACST  Maximum libration 19:30 ACST	First Quarter Moon April 28 19:02 ACST apogee 16:30 ACST	First Quarter Moon November 20 21:02 ACDST perigee 22nd 18:30 ACDST

 A year of full Moons showing the variation in size as the moons move from perigee to apogee. I also show the apogee and Perigee First Quarter Moons. All the moons are shown on the day and time they are full (unless they are below the horizon, in which case the size at astronomical twilight is shown), and although this is not the optimal time for size comparisons, you can clearly see the size difference over the year (compare Feb 6 to Aug 31) the original scale for all is 2 degrees of field of view cropped down). Although the field rotation of the Moon makes it less clear, you can also see the effect of libration.

In 2023 we have two good Perigee Moons in a row (August 2, August 31), one of which is a “Blue Moon” (August 31). However, as you can see the differences are subtle, and it requires a keen eye and good memory to distinguish a perigee "super" Moon from more ordinary moons, the best contrast is with the apogee "mini" moon of February 6, even though this is not a good apogee Moon).

That doesn't mean you shouldn't try though. Daniel Fischer has been able to see the difference, you can read his account and viewing tips here:
http://earthsky.org/space/can-you-discern-supermoons-large-size-with-the-eye-an-observer-says-yes

Photographing them can be more rewarding. You can see images of perigee Moon and apogee Moon pairs from 21 Jan 2019 here and 10 August 2014 here.Tips for photographing them are here.

There is also a penumbral Lunar Eclipse on 5/6 May and a poor Partial Lunar eclipse favouring WA on October 29 in the early morning.

Labels: apogee, Moon, perigee, public outreach, Yearly Moons

The First Quarter Moon is Sunday January 29. Jupiter is easy to see as brightest object in the western evening sky aside from the Moon. The crescent Moon is close to Jupiter on the 26th. Bright Mars, the red star Aldebaran and the Pleiades cluster form a triangle. This triangle is joined by the Moon on the 30th, and the Moon is close to Mars on the 31st.  Venus climbs higher in the evening twilight, and soon will challenge Jupiter for brightest evening object when it leaves the twilight.

The First Quarter Moon is Sunday January 29.

Morning sky on Saturday, January 28 as seen from Adelaide at 05:29 ACDST, (60 minutes before sunrise, click to embiggen). Mercury is below the Scorpius.

   

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

 

Evening sky on Saturday, January 28 as seen from Adelaide at 21:09 ACDST, (45 minutes after sunset, click to embiggen). Venus is low above the horizon with Saturn below. You will need a low, unobstructed horizon to see Venus clearly. You will need binoculars to glimpse Saturn. This will be your last opportunity to see Saturn before it is lost in the twilight.

   

Similar views will be seen from the rest of Australia at the equivalent local time (45 minutes after sunset). 

 Evening sky on Monday, January 30 as seen from Adelaide at 22:05 ACDST, 90 minutes after sunset (click to embiggen). Mars, the red star Aldebaran and and the Pleiades cluster form a triangle. The waxing Moon is near the Pleiades. The following night it is near Mars.

Jupiter is seen low in the west

 

Mars was at opposition, when was at its biggest and brightest as seen from Earth, on December the 8th, but is still an excellent sight. The insets are the telescopic views of Mars and Jupiter at this time.

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

Labels: weekly sky

 Evening sky on Monday, January 23 as seen from Adelaide at 21:16 ACDST, (45 minutes after sunset, click to embiggen). Venus is low above the horizon close to Saturn with the thin crescent Moon nearby.You will need a low, unobstructed horizon to see Venus clearly. You may need binoculars to glimpse Saturn.

   

Similar views will be seen from the rest of Australia at the equivalent local time (45 minutes after sunset).

The January edition of Southern Skywatch is now up. 

This month Venus, Saturn, Jupiter and Mars grace the evening sky. Saturn is soon lost to view and Mercury is visible in the morning skies.

January 3; the Moon is close to Mars. January 7; Full Moon. January 5; Earth at perihelion. January 8; apogee Moon. January 15; Last Quarter Moon. January 21; the thin crescent moon near Mercury in the morning sky. January 22; New Moon. January 22; Moon at perigee. January 23; the crescent Moon is close to Saturn and Venus low in the twilight. January 26; the crescent Moon is close to Jupiter. January 29; First Quarter Moon. January 31; the Moon is close to Mars again.

Mercury is in the morning sky, and is readily visible in the eastern morning twilight from about mid month. Mercury is at its furthest from the Sun on the 30th, when it is highest above the horizon. On the 20th and then the 21st the thin crescent Moon is near Mercury. 

Venus Venus is in the western twilight and is visible an hour after sunset by the end of the month. Saturn is above Venus and comes closer towards the end of the month. On the 22nd and 23th Venus is less than a finger-width from Saturn, on the 23rd the pair are joined by the thin crescent Moon. You will probably need binoculars to see Saturn, and a level, unobstructed horizon the see Venus at it's best. 

Earth is at perihelion on 5 January when it is closest to the Sun.

 Mars spends January forming a triangle with the bright red star Aldebaran and the beautiful Pleiades star cluster. While Mars continues to dim after opposition last month, it remains one of the brightest objects in the sky and easily recognizable. On the 3rd and 31st Mars is close to the waxing Moon. 

Jupiter is lowering into the western evening sky, it is still easily recognizable as the brightest object in the early evening sky (after Venus sets in the twilight). On the 26th Jupiter is near the crescent Moon.  

Saturn is low in the evening twilight then is lost to view in late January. During the month Saturn comes closer to Venus, and on the 22d and 23rd the pair are less than a finger-width apart. On the 23rd the thin crescent Moon joins the pair. You will need binoculars to see Saturn and a level, unobstructed horizon will be needed to see the pair at their best.

 

 

Labels: southern skywatch

The New Moon is Sunday January 22. Jupiter is easy to see as brightest object in the western evening sky aside from the Moon. The crescent Moon is close to Jupiter on the 26th. Bright Mars, the red star Aldebaran and the Pleiades cluster form a triangle.  Venus climbs higher in the evening twilight, and soon will challenge Jupiter for brightest evening object when it leaves the twilight. Saturn meets Venus and  crescent Moon in the twilight on the 23rd. The thing crescent Moon is near Mercury in the morning twilight.

The New Moon is Sunday January 22. The Moon is at perigee, when it is closest to the Earth, on the 22nd as well. 

Morning sky on Friday, January 20 as seen from Adelaide at 05:18 ACDST, (60 minutes before sunrise, click to embiggen). Mercury is below the thin crescent Moon. On the morning of Saturday it is just above it.

   

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

 

Evening sky on Monday, January 23 as seen from Adelaide at 21:16 ACDST, (45 minutes after sunset, click to embiggen). Venus is low above the horizon close to Saturn with the thin crescent Moon nearby.You will need a low, unobstructed horizon to see Venus clearly. You may need binoculars to glimpse Saturn.

   

Similar views will be seen from the rest of Australia at the equivalent local time (45 minutes after sunset).

 Evening sky on Thursday, January 26 as seen from Adelaide at 22:05 ACDST, 90 minutes after sunset (click to embiggen). Mars, the red star Aldebaran and and the Pleiades cluster form a triangle. Jupiter is seen low in the west

 

Mars was at opposition, when was at its biggest and brightest as seen from Earth, on December the 8th, but is still an excellent sight. The insets are the telescopic views of Mars and Jupiter at this time.

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

Labels: weekly sky