Blue-white subgiant · Crux

Imai

Also known as: δ Crucis (δ Cru), HIP 59747

mag 2.8350 light-years

About

Imai (δ Crucis) is a blue-white subgiant of magnitude 2.8 in Crux, about 350 light-years away.

Imai is in the constellation Crux.
Best evenings: around mid-May it is highest at about 9 pm (10 pm in summer time); a month earlier, two hours later.
Where on Earth: it is seen well, at least 10° up, from south of 21° N.
Star patterns: Southern Cross and the Pointers.

When it rises and sets tonight, how high it climbs and how much the Moon gets in the way are worked out in your browser for your place.

EyesEasy, even from town.
Binoculars (10×50)A sharp point; binoculars bring out its colour and the fainter stars around it.
Telescope (6–8 inch)Still a point of light at any magnification — stars are too far away to show a disc. Low in the sky, bright stars twinkle and flash colours.

Stars look the same in any instrument: brighter and sharper, but never bigger.

Proper name	Imai
Designation	δ Crucis (δ Cru)
Hipparcos number	HIP 59747
Type	Blue-white subgiant
Spectral type	B2IV
Colour	Blue-whiteB−V colour index −0.19
Magnitude	2.8The smaller the number, the brighter.
Distance	350 light-yearsThe light you see left it around 1680.
Proper motion	0.038″ per year across the sky
Constellation	Crux
Right ascension (J2000)	12h 15m 08.7s
Declination (J2000)	−58° 44′ 56″

Star data: HYG Database by David Nash, CC BY-SA 4.0. All data sources →