Download The Sky This Month

The Sky This Month
Joel Swallow
The Sky This Month
• Decoding Astronomy : The Magnitude Scale
• The Moon this month
• The planets this month
• Jupiter’s Galilean Moons
• Vernal Equinox (March 20th)
• Interesting stars in Cepheus
• Messier Objects : Spiral Galaxies
[4]
Clocks go forward on March 26th – BST
Decoding Astronomy : The Magnitude Scale
[21]
Dark Skies
Limited to stars
brighter than mag. 4
Can see stars fainter than mag. 7
(But you will need some
binoculars!)
[22]
[1]
The Moon This Month
Full Moon: March 12th
New Moon: March 28th
Full Moon: April 11th
[2]
[3]
The Planets This Month
[10]
Mercury and Venus : lost to the sun!
08:30
9/3/17
Mars – Dimming From Pisces to Aries
• During March Mars dims from mag 1.3 to 1.5 as it moves from Pisces to Aries
20:00
8/3/17
20:00
29/3/17
Jupiter – In Virgo at about mag -2.4
• Currently rising ~ 9pm but getting earlier,
rising before 8pm by the end of the month.
01:00
9/3/17
Jupiter – In Virgo at about mag -2.4
• Moon and Jupiter get very close! 14/15 of March
01:00
15/3/17
Saturn – mag 0.4
• Look to the south
before dawn.
• Rises later over
the course of the
month.
• Tougher to see
when it rises later
due to the rising
sun.
05:20
9/3/17
Uranus – In Pisces mag 5.9
• VERY tricky to see – getting lost
in the sun as the month goes on!
20:10
8/3/17
The Galilean Moons
• 4 largest moons of Jupiter
discovered by Galileo.
• Size comparison to the
Earth and our Moon.
• Biggest Moons In the Solar
system:
1.
2.
3.
4.
5.
6.
Ganymede
Titan
Calisto
Io
Moon
Europa
(Jupiter)
(Saturn)
(Jupiter)
(Jupiter)
(Earth)
(Jupiter)
[5]
The Galilean Moons
• Each night the positions of
the moons will change.
Galilean
Moon
Orbital
Period
[Earth
days]
Io
Europa
1.77
3.55
0.262
0.416
Ganymede
7.16
0.664
Calisto
16.7
1.17
Distance from
Jupiter *
[million miles]
*Earth-Moon = 0.238
(mag. 4.6 – 5.6)
The Galilean Moons
[11]
[12]
Vernal Equinox
[13]
Monday, 20 March 2017, 10:29 GMT
Vernal Equinox
Marks the beginning of Astronomical Spring
• Equi (equal) nox (night) – equal night and day…approximately.
• On the Equinox the Sun shines down directly on the equator – your
shadow is just beneath your feet.
• Winter Solstice : Sun directly overhead at the (northern) tropic of Cancer.
• Summer Solstice : Sun directly overhead at the (Southern) tropic of
Capricorn.
[14]
Cepheus & Interesting Stars
• Look to the North to find Cassiopeia
and Cepheus.
21:00
8/3/17
Cepheus & Interesting Stars
• Look to the North to find Cassiopeia
and Cepheus.
𝛿 Cep
21:20
12/3/17
[19]
• Deep red Garnet Star. (Mag 4.2).
• Red supergiant, one of the largest stars we know about!
• 4200 x Sun’s diameter.
The Garnet Star
(𝜇 Cep)
Cepheus & Interesting Stars
[20]
• Delta Cephi (Mag 4.05): prototype Cepheid Variable Star
• From the period of pulsation we can find how bright it really is and compare
to how bright it appears and therefore find its distance.
• Forms a rung on the Astrophysical distance measurement ladder.
Messier Objects – Spiral Galaxies
[18]
M51 : The Whirlpool Galaxy
• M51 is easy if the sky is dark – but tricky with too much light
pollution or moonlight!
Distance: 23 million ly
Visual Brightness: 8.4 (mag)
Apparent Dimensions: 11×7 (arc min)
M51
22:00
8/3/17
M51 : The Whirlpool Galaxy
[16]
What will I see?
• Binoculars : fuzzy blob.
• Small telescope : Bright galactic
core(s).
• 8’’ + telescope : hint of spiral arms
and dust lanes.
M51, taken April 22, 2006 with
5-inch apo refractor at f/4.5 and
Canon 20Da camera at ISO400.
Four 10-minute exposures
average-stacked.
M51 : The Whirlpool Galaxy
• What will I see?
Hubble…
[17]
M 101 : The Pinwheel Galaxy
M101
• Quite large (29’ x 27’) and feint (mag. 7.86) – best
seen with low power eye piece (lower magnification).
22:00
8/3/17
M 101 : The Pinwheel Galaxy
• Taken April 23, 2006
• with 5-inch aperture
refractor at f/4.5
• Canon 20Da camera at
ISO400.
• Four 10-minute exposures
average-stacked.
M 101 : The Pinwheel Galaxy
• Huge galaxy, with 70%
more mass than the Milky
Way.
• 21 million ly away
• Photons we observe
tonight were emitted 21
million years ago.
[15]
The Sky This Month
• Decoding Astronomy : The Magnitude Scale
• The Moon this month
• The planets this month
• Jupiter’s Galilean Moons
• Vernal Equinox (March 20th)
• Interesting stars in Cepheus
• Messier Objects : Spiral Galaxies
• M51 and M101
[4]
Clocks go forward on March 26th – BST
The Sky This Month
Joel Swallow
Photo Credit
1.
http://www.moongiant.com/phase/03/08/2017
2.
http://www.littlethings.com/full-moons-2016/
3.
http://shewhodreams.weebly.com/april---pink-moon.html
4.
https://saviorssoup.files.wordpress.com/2014/10/thief-at-night.jpg
5.
http://2.bp.blogspot.com/-yrjROnUTRtk/UHugMvnzj1I/AAAAAAAABnQ/1N27MdbNuoI/s1600/787px-Galileanasnom.PNG
6.
http://www.paullknight.com/wp-content/uploads/2013/03/K01_8312-2.jpg
7.
http://sbo.colorado.edu/SBO_OLD_SITE/sbo/astroinfo/galileo/galileo.voyager.jupiter.jpg
8.
https://eclipse.gsfc.nasa.gov/LEplot/LEplot2001/LE2017Feb11N.pdf
9.
http://www.moongiant.com/Lunar_Eclipse_Calendar.php
10.
http://www.swindonstargazers.com/telescope/planets.jpg
11.
http://earthsky.org/astronomy-essentials/top-tips-for-using-ordinary-binoculars-for-stargazing
12.
http://www.resonancepub.com/images/telescope_cartoon.gif
13.
http://firstdayof.org/wp-content/uploads/2015/12/vernal-equinox-2016-march.jpg
14.
http://www.worldatlas.com/aatlas/newart/imagee.gif
15.
https://en.wikipedia.org/wiki/Pinwheel_Galaxy#/media/File:M101_hires_STScI-PRC2006-10a.jpg
16.
http://binocularsky.com/images/objects/M51-100.png
17.
https://www.nasa.gov/sites/default/files/images/420970main_M51HST-GendlerMr_full.jpg
18.
http://www.absoluteaxarquia.com/nightsky/images/messier_6.jpg
19.
https://en.wikipedia.org/wiki/Mu_Cephei#/media/File:Star-sizes.jpg
20.
https://writescience.wordpress.com/tag/cepheid/
21.
http://timtrott.co.uk/magnitude-scale/
22.
http://www.universetoday.com/wp-content/uploads/2014/12/Dark-sky-magnitude-scale-Inter-Dark-Sky-Assn.jpg