Night Sky: April 2019

The Moon and Mars will make a close approach, passing within 4°35' of each other (figure 1a & 1b). Moon will be 4 days old.

They will become visible at approximately 20:21 (GMT) as dusk sky fades, 35° above Western horizon. They then move towards the horizon, setting 4 hours and 36 minutes after the Sun at 00:34.

They will be too widely separated to fit within the field of view of a telescope, but will be visible to the unaided eye or through a pair of binoculars.

Figure 1a: Illustration of the relative 'tilt' in the orbits of Earth and Mars (Moon not shown). Credit, NASA.

At about the same time, the two objects will also share the same right ascension called a conjunction (figure 2).

Figure 1b: Photograph of Moon and Mars in conjunction.

Figure 2: Right ascension (blue) and declination (green) as seen from outside the celestial sphere.

Right ascension (abbreviated RA; symbol α) is the angular distance of a particular point measured Eastward along the celestial equator from the Sun at the March equinox to the (hour circle of the) point above the Earth in question.

Virginid meteor shower: 12th April. Will reach maximum activity on 12th April. Some shooting stars associated with the shower should be visible each night from 7th April to 18th April (figure 3).

The radiant of the shower will appear 27° above Southern horizon at midnight. You are likely to see approximately 2 meteors per hour, as the radiant will be low in the sky, this reduces chances of seeing meteors.

Radiant of the shower is at approximately right ascension 14h 00m, declination 9° S. All meteors will appear to be travelling directly outward from this point.

The Moon will be 7 days old, presenting interference in the early evening sky.

To see the most meteors look at dark patches of sky around 30°–40° away from the radiant. This distance from the radiant, meteors will show reasonably long trails without being too spread out.

Figure 3: Virginid meteor shower and constellations.

M3 is in good position: 18th April.                                               The globular cluster M3 (NGC 5272) in Canes Venatici will be well placed for observation. Reaching the highest point in the sky at midnight. Easier to see from the Northern hemisphere. Visible all night from 21:42 (GMT) as the dusk sky fades, 44° above Eastern horizon. Lost to dawn twilight at 04:44, 44° above Western horizon. M3 is quite faint, and not visible to the naked eye, but can be viewed using a pair of binoculars or small telescope (figure 4).                   33900 light years away from Earth.

Figure 4: M3. Credit: Mount Lemmon Sky Centre.

Lyrid meteor shower: 23rd April. Maximum activity 23rd April. Showers are expected to be visible each night from 19th to 25th.

The radiant appearing 37° above Eastern horizon at midnight. Viewing approximately 6 meteors per hour, since the radiant will be high in the sky, maximising chances of seeing meteors (figure 5).

Figure 5: Lyrid meteor shower.

WARNING: Never attempt to view through binoculars, telescope or any optical aid an object close to the Sun. Also, never attempt to view the Sun unaided, doing so may result in immediate and permanent blindness. Always use astronomical approved viewing equipment.

The Stellarium software will assist greatly in locating objects in the sky.

Mark R Smith FRAS

Physicist

Nuclear Fusion & Astrophysics.