In Manx skies... April 2008 ~ compiled by Dave Storey

Moon

New
6^th at 03.55h

First Quarter
12^th at 18.32h

Full
20^th at 10.25h

Last Quarter
28^th at 14.12h

There are no Lunar or Solar Eclipses this month.

Graphic © Copyright CalculatorCat.com

Note: All times are Universal Time (UT)
BST started on 30^th March. Add 1 hr. to any quoted times to get local IoM time.

Mercury

Reaches superior conjunction the 16^th and will not be visible until the end of the month when it moves into the evening sky. The planet is well placed for observation from Manx shores during the last days of April and the first week of May. Try looking for the planet on the west horizon after sunset with a pair of binoculars during the last week of the month. Once located, it should be easily seen with the naked eye in the bright twilight sky at magnitude -1.3 to -0.9

Venus

Is poorly placed for viewing this month. It is still a morning object and is moving closer to the sun.

Mars

Resides in Gemini for the whole month and is moving in a west to east direction towards the two bright stars of Castor and Pollux. The planet is bright at +0.8, fading to +1.2 by the end of the month as it recedes from earth. The diameter of the planet is too small to see any indications of surface details.

Jupiter

Can be found in Sagittarius in the morning sky. It rises at about 03.15h at the start of April and rising at 01.25h at the end of the month. It shines at a bright
-2.1 to -2.3 and will be unmistakable low down in the eastern sky. Through a telescope, you will be able to make out the north and south equatorial belts that run parallel with the Jovian equator. Also, observe the four Galilean moons that change positions either side of the planet. For a graphic representation of the Galilean moons visit the Sky & Telescope “Jupiter Moons” web page.

Saturn

Shines at a bright +0.3 about 2.5 degrees east of the star Regulus in Leo. The planet is the brighter object. Through a telescope, the rings will be presented at an angle of -9.5 to -9.9 degrees to us with the southern face of the rings on view.
The bright moon Titan can be seen west of Saturn on 14^th, 15^th, 16^th , 30^th, and east of the planet on 6^th, 7^th, 8^th, 22^nd, 23^rd, 24^th.

Uranus

Is poorly placed for viewing as it is at the far side of the sun this month.

Neptune

As with Uranus, the planet is poorly placed for observing.

Meteors

Virginids are slow moving meteors that can be seen during March and April with two radiants in the sky. One of the radiants is active from 7^th to 18^th April. There is a maximum peak of 5 meteors per hour on the 10^th.
Lyrids are visible during the period 19^th - 25^th with a maximum due on 22^nd at 04hrs. In ideal conditions, 10 meteors per hour are expected but there will be a gibbous moon in the sky at this time and the meteor shower will be unfavourable for good observed rates.
Eta-Aquarids are active during the last week of April with a maximum peak on May 4^th, when 40 meteors per hours can be seen in ideal conditions.
Alpha-Scorpiids is a weak shower that is active between 20^th April through 19^th May. There are two maximum dates on 27^th April and 12^th May when 5 meteors per hour can be seen in ideal conditions.

Algol

This star drops from magnitude +2.1 to +3.4 in about 5 hours. Minimum of this star is reached on the following dates as seen from the IoM: 8^th at 03.36h, 11^th at 00.24h and 13^th at 21.12h. Click here for star chart

Comet

There are no predicted bright comets. As with previous months sky notes, it will be worth while keeping a eye on the very faint comet 17P Holmes. This comet is normally at a very faint magnitude of +20 but went into naked eye visibility in October 2007 and was naked eye into the New Year. At the time of writing these notes ( 28^th February) the comet is no longer visible to the naked eye but is still a large diffuse object when imaged with long exposure photography.

The Stars

Graphic based from Guide 8 software. Click here for High Resolution Graphic

Leo is due south at 9pm in the middle of April and there are a number of objects worth seeing. Firstly, the actual constellation does actually resemble the name tagged to it. The head of the lion is in the form of a backwards question mark known as the Sickle, with the star Regulus at the question mark base. Regulus is the brightest star in Leo shining at magnitude +1.4 and is the 21^st brightest star in the sky. Its distance is 84 light years and shines 170 times brighter than our sun. The constellation shape is altered by the presence of Saturn to the left of Regulus. Through a telescope, a close companion star to Regulus can be seen at Position Angle (P.A.) of 307 degrees and separation (Sep.) of 177 arc seconds. The companion star is much fainter at +7.7

Further north within the Sickle is another double star named Algieba. Algieba shines at magnitude +2.2 and its +3.5 companion star is in P.A. 125 degrees Sep. 4.4” arc seconds. The colours of the stars are orange and yellow and is a splendid telescopic sight. These stars are in orbit around each other with a period of just over 6 centuries.

Along the bottom edge of the constellation is a stream of faint galaxies that will require a good telescope and dark skies to see. They are visible as faint fuzzy patches and they will become visible when your eyes have become dark adapted. The galaxies M95, M96 and M105 (magnitudes +9.7, +9.2 and +9.3) form a triangle known as the Leo Triplet galaxies. They are about 33 million light years distant. Further over to the west are M65 and M66 (magnitudes +9.3 and +9.0) Above these two galaxies is a faint edge on spiral galaxy NGC3628. This is a target for CCD imagery and it is a beautiful galaxy to image. See Left.

A variable star that is suitable for a small telescope to observe is R Leonis. This is a Mira type variable that has a maximum brightness roughly every 310 days. The star is currently fading this month from magnitude +5.5 in December and will fade to about +10 over the coming months. When at its brightest, the star looks distinctly red when viewed through a pair of binoculars. Using the star chart here, try to estimate the magnitude of R Leonis in comparison with the other marked stars every 5 days or so. Then over the year, you will be able to produce a light curve showing the star changing brightness over time.

Graphic based on Guide 8 software and magnitudes from AAVSO sequence number 080301