Watch this Space for May 2015

Moon Phases Planet Watch

The Planets on view this month are: New Moon First Quarter 18/ 05 / 15 25/ 05 / 15 Mercury: in Tau, visible about 22:00 in the NW Venus: mag -4.1 in Tau/Gem, sets about 00:30 Full Moon Last Quarter Mars: not visible this month 04/ 05 / 15 11/ 05 / 15 Jupiter: mag -1.9 in Cnc, sets about 02:00 Saturn: mag +0.2 in Lib, at opposition on 23rd The Sun Uranus: not visible this month Rises: 05:16, 15th May, Sets: 20:46 Neptune: mag +7.9 in Aqr, rises about 03:00 Constellations of the Month Centaurus Centaurus is a large southern constellation , and has no myths associated with it. It represents the centaur, the half man, half horse creature from Greek mythology. It is 9th out of the 88 Constellations in size (1060 sq. deg.) Notable stars:  Cen - Multiple star, 4.32 ly away. A is a G2 very similar to the Sun and B is a slightly smaller K2 star. C, the third component is “Proxima” a M5 red dwarf, the

closest star to us is about 2 from the A/B system. Constellation map credit:  Cen - Triple star system, 350 ly distant. A is a spectroscopic binary IAU and Sky &Telescope magazine (cropped) of almost identical B1 giant stars. B is a mag 3.7, B2 dwarf at 1.3” distant. V886 Cen - The “Diamond Star”. A carbon star of unusually high mass believed to have a crystalline carbon core. Nicknamed this star "Lucy" after the Beatles song "Lucy in the Sky with Diamonds." Some Interesting Objects: Centaurus contains over 169 NGC objects including 18 open clusters, 2 globular clusters, 143 galaxies, 3 planetary nebulae and 1 reflection nebula. There are no Messier object but there are 6 Caldwell objects. C77 - NGC 5128, Centaurus A. Peculiar galaxy with a central supermassive black hole and dust lane across its centre. It is about 10-16 Mly distant and is the 5th brightest galaxy visible. It emits radiation in all parts of the spectrum from X-ray to radio. C80 - NGC 5139, Omega Centauri. Largest and brightest globular cluster, mag 3.9, distance 15.8 kly. C83 - NGC 4945, spiral galaxy, mag 9.3 C84 - NGC 5286, globular cluster, mag 7.6 C97 - NGC 3766, “The “Pearl” open cluster, mag 5.3 C100 - IC 2944, “The Running Chicken” or  Centauri nebula, mag 4.5

C77, NGC 5128, Centaurus A C80, NGC 5139, Omega Centauri C100,  Centauri nebula Images: Steve Broadbent, iTelescope T31, both 25min total LRGB Image: ESA 2.2m telescope

Lunar Feature of the Month - Wargentin Noted as an “exceptional formation” Wargentin is rather unusual in its appearance. To locate this crater you need to navigate to the lunar south western limb. Once here the large crater Schikard can be used to help find Wargentin which lies just south of Schikard. The best times for observation include 5 days after First Quarter or 4 days after Last Quarter. This crater is unusual as the crater’s floor is filled with lava from the impact that created Wargentin, some 3.8 billion years ago. The impact caused the lunar surface to leak lava and fill the crater virtually to the rim, this subsequently created a lunar plateau that rises from the moons surface. The craters floor is filled with numerous smaller craters and craterlets and a series of wrinkle ridges, looking somewhat like the footprint of a bird, can also be observed. Wargentin. An image from Lunar Orbiter 4 taken in 1967 ©NASA The Sun in April Credit: Space Weather On April 30, a virtually spotless Sun.

There have, however, been some fine filaments and prominences. This splendid example was almost as long as the Earth-Moon distance.

On April 29th, it erupted, producing a CME, which was not Earth-bound.

Credit: Space SOHO Credit: Göran Strand. 27/4/2015. Östersund, Sweden

ISS and Iridium Flares this month ISS visibility ISS night-time visibility, magnitude greater than –2.0, height greater than 30° Zenith Start End Date Time Mag Dirn Ht Dirn Ht Dirn Ht No evening passes

Satellite events Transits of Sun and Moon longer than 1s, and night- Satellite flares time close passes. Magnitude greater than -4.0, height greater than 30° Date Time Event Date Time Satellite Mag Dirn Ht Thu 7 May 9:28 ISS transit of Sun Wed 6 May 23:27 Iridium 72 -6.0 WSW 33° 12:41 ISS transit of Sun Sat 9 May 20.:15 Iridium 42 -6 E 78° Sun 10 May 8:25 ISS transit of Sun Sun 10 May 20:11 Iridium 40 -6.6 E 80° 11:36 ISS transit of Sun 23:11 Iridium 74 -5.1 WSW 32° Thu 14 May 9:39 ISS transit of Sun Mon 11 May 20:05 Iridium 77 -5.0 E 82° Fri 15 May 7:10 ISS transit of Sun Wed 13 May 21:34 Metop B -5.0 NE 73.5° 8:46 ISS transit of Sun Fri 29 May 23:21 Iridium 20 -4.3 WSW 38° Data from CalSky: http://www.calsky.com