San Pedro - April 9, 2018

Coalsack Nebula
Time: 9:15 PM EST 
Instrument: Visual
S&T Chart Reference: 49, 50
You can't miss this nebula below Crux - it's massive, covering an area of 7º x 5º in the sky! Consists of thick clouds of dust and gas - the perfect materials for star formation. It is very dark. I will have to use binoculars next time to see what I can see.

Large Magellanic Cloud (LMC) / PGC 17223 / Nubecular Major
Small Magellanic Cloud (SMC) / PGC 3085 / Nubecual Minor
Time: 9:19 PM EST 
Instrument: Visual
S&T Chart Reference: 10, 20, 30
The SMC was ~ 20º below the LMC at about 6:30 o'clock. The LMC and SMC are irregular galaxies that look more like nebula at first glance.

LMC:
Magnitude: 0.9
Size: 10.75º x 9.17º and contains a very prominent warped bar at its centre with a spiral arm tipped at 35º
4th largest Galaxy in the Local Group after M31, Milky Way and M33 (Triangulum Galaxy)

SMC:
Magnitude: 2.7
Size: 5º 20' x 3º 5' and contains a central bar structure (that may have once been a barred dwarf spiral galaxy).

PM45 (Pleiades)
Time: 9:30 PM 
Instrument: Visual + Binoculars 
S&T Chart Reference: 14, 15, A

Located this open cluster visually. It was very bright using the binoculars; the stars and nebulosity were fairly clear in the FOV. I didn't sketch it this time but hope to in the near future.

Crux / Southern Cross
Time: 10:10 PM EST 
Instrument: Visual
S&T Chart Reference: 38, 49, 50
Amazing to see Crux for the first time! So clearly visible even though it's the smallest of the 88 constellations.

Stars of Crux:
- Acrux (α Crucis): Blue white double star, 4.4 arc second separation. 14th brightest in the sky. 
Magnitude 1.4 & 1.9
- Mimosa / Becrux (β Crucis): White star. 20th brightest star in the sky. Magnitude 1.30
- Gacrux (γ Crucis): Red Giant belonging to the spectral class M4III. 26th brightest star in the sky. Magnitude 6.4
- Imai (δ Crucis): β Cephei type variable star. Magnitude 2.775

Omega Centauri / NGC 5139 (in Centaurus)
Time: 10:16 PM EST
Instrument: Visual + Binoculars + TeleVue 60
S&T Chart Reference: 48, 49, 59
Omega Centauri, a globular cluster in Centaurus, is the largest globular cluster in the Milky Way and is easily seen naked eye. The core of the cluster is very tight and almost looked like a solid body. The outer edges of the cluster were still quite compact with many, many stars near the tight core - all in all, quite a compact and bright cluster.

How to Find Omega Centauri:
1- Locate α Centauri and β Centauri, and the distance between them.
2- Visually go up from there an equal distance.
3- The go about 60º using the same length from that previous point.
4 - Et voilá!

Corvus
Time: not recorded
Instrument: Visual
S&T Chart Reference: 47
Although I had first seen this constellation in Florida, it was much higher in the sky in Chile.

Stars of Corvus:
Gienah: Brightest at mag 2.6, blue-white giant.
Algorab: wide binary system at mag 3 & 8
Alchiba: 5th brightest star even though it has the alpha designation.

Musca ("the fly")
Time: 9:45 PM EST
Instrument: Visual
S&T Chart Reference: 50
This constellation was pointed out during the general tour of the night sky by Alain. Fairly close to the Coalsack Nebula and Crux. Interesting that 3 of its stars have planets.

Musca Stars:
- α Muscae: blue-white star with mag 2.7
- β Muscae: Binary star system composed of 2 blue-white main sequence stars
- γ Muscae (tail of the fly): blue-white star that varies between mag 3.84-3.86 over 2.7 days
- ζ2 Muscae: white main sequence star. Part of a triple star system with faint companions at 0.5 and 32.4 arc seconds distance.
- η Muscae: Multiple star system, 2 main components forming an eclipsing binary with mag 4.77 that dips by 0.05 mag every 2.39 days.
- δ Muscae: orange giant at mag 3.62
- ε Muscae: red giant and semi-regular variable. Mag 3.99-4.31 over 40 days
- μ Muscae: orange giant mag 4.7.1-4.76; slow irregular variable
- λ Muscae: 3rd brightest star in the constellation; white main sequence star