VY Canis majori

[mikemasey (Mike)]

Who can assist me with finding VY Canis majori?
I have read that it is the biggest known star and is in the Canis major constalation but I cant find it on any star charts,(VYCMa) ?
thanks.

[Coen]

Not far from Tau heading towards Puppis at about 7h 23m; -25d 50m

Variable star between mag 6.5 and 9.6 or so (I also have figures of 7.5 to 8.8). Also cataloged as HIP 35793, TYC 6541-2525-1, ASCC 1642287 in case you wish to search SIMBAD. Approximate distance 2000 or so light years.

But then again I could be wrong.

Attached is a zoomed map of the VY area, generated via CNebulaX and another one from CdC.

[erick (Eric)]

I've had this red hypergiant on my target list for a year - time to hunt it down this Summer so I can say I've gazed at it!

"University of Minnesota professor Roberta M. Humphreys[1] estimates the radius of VY CMa at 1800 to 2100 solar radii.[2] To illustrate, if our Sun were replaced with VY Canis Majoris, its surface would extend to the orbit of Saturn. Assuming the upper size limit of 2100 solar radii, light would take more than 8 hours to travel around the star's circumference, as opposed to 14.5 seconds for the sun."

I just gotta see the fella!

I found I had to locate it the hard way. Wikipedia gives the RA and Dec:-

Right Ascension 07h 22m 58.29s
Declination -25deg 46min 03.5sec

I just blew up Stellarium at this location and searched and I'm sure that it was fairly clear which star it was. Magnitude is reported as 9.5 so not particularly distinctive. I recall that it was not going to be an easy starhop which is probably why I haven't put the time in as yet.

[astroron (Ron)]

You need probably a 12" or more to see it's one sided nebula.
It is only small in the eyepiece

[Coen]

Link to SIMBAD entry:
http://simbad.u-strasbg.fr/simbad/si...bmit=submit+id

Also note that it appears to be a multiple star too (from CdC):
07h23m00.43s -25°46'01.0" V* HIP 35793 T:L mMax: 7.44 mMin: 8.76 P: 0.0000000000 Mepoch: 0.0000000000 sp:M3/M4II: desc:VY_CMa NewVar: HvarType:U mV: 8.08 maxMag:7.444 med_Hp:7.961 minMag:8.762 A:1.099 e_A:0.137 max_lit:6.5 min_lit:9.6
07h23m00.42s -25°46'01.1" D* TDSC 19197 A-B m1: 9.75 m2:10.34 sep: 1.0 pa:261 Tycho2:6541 02525 1 WDS:07230-2546 HD:58061
07h23m00.40s -25°46'00.8" D* WDS B 719 AB m1: 9.75 m2:10.34 sep: 1.0 pa:261 date:1991.00 sp: 1 M3/4III; desc:ND BD-25.04441
07h23m00.40s -25°46'00.8" D* WDS SEE 78 AB-C m1: 7.50 m2: sep: 2.6 pa:290 date:1970.00 sp: 1 desc BD-25.04441
07h23m00.40s -25°46'00.8" D* WDS SEE 78 AB-D m1: 7.50 m2: sep: 3.5 pa:349 date:1936.00 sp: 1 desc:
07h23m00.40s -25°46'00.8" D* WDS SEE 78 AB-E m1: 7.50 m2: sep: 6.9 pa: 31 date:1900.00 sp: 1 desc:
07h23m00.40s -25°46'00.8" D* WDS SEE 78 AB-F m1: 7.50 m2: sep: 1.0 pa:103 date:1970.00 sp: 1 desc:
07h23m00.43s -25°46'01.1" * ASCC 1642287 mV: 9.09 mB:10.63 sp:M3/M4II: pmRA: 0.002 pmDE:-0.007 px:0.0016 Dist:2038.5 ly TYC:6541025251 HIP: 35793 HD: 58061 DM:-2504441
07h23m00.36s -25°46'01.2" * HIC 35793 mV: 8.60 b-v: 2.20 sp:M3/M4II: pmRA:-0.011 pmDE: 0.004 Epoch: 2000.00 px:0.0000 desc: N BD: CD:CD -25 4441 CPD:CPD-25 2286 HD: 58061 FK:S 7681 AG: SAO:173591 CCDM:07230-2546 Vname:VY CMa VarType: Period:0.0 Vmax:6.5 Vmin:9.6 q_Vmax:2.0 PA:200.0 Sep:0.6 Dmag:1.3 Hp:8.4 Vmag:8.6 e_Vmag:0.5
07h23m00.44s -25°46'01.0" * HIP 35793 mV: 8.08 b-v: 2.06 sp:M3/M4II: pmRA: 0.010 pmDE: 0.001 px:0.0018 Dist:1812.0 ly BT:11.601 VT:9.16 V-I:3.08 Hpmag:7.9607 Hpscat:0.396 VarPer:0.0 pa:0.0 sep:0.0 Dmag:0.0
07h23m00.15s -25°45'59.0" * HIC 35793 mV: 7.80 pmRA:-0.035 pmDE: 0.022 CCDM:07230-2546 Note1: Note1: DM:CD -25 4441 HD: 58061 AG: 173591 IDS:07189S2535 A ADS: 6033 rComp: Comp:A PA:0.0 Sep:0.0 Obs:0.0
07h23m00.15s -25°45'59.0" * HIC 35793 mV: 9.10 pmRA:-0.035 pmDE: 0.022 CCDM:07230-2546 Note1: Note1: DM: HD: AG: IDS:07189S2535 B ADS: 6033 rComp: Comp:B PA:200.0 Sep:0.6 Obs:1959.0
07h23m00.44s -25°46'01.0" * Sky CD-25.04441 mV: 8.93 b-v: 2.04 sp:Ma pmRA: 0.010 pmDE: 0.001 HD:58061 SAO:173591 Sep:0.8 Dmag:1.3
07h23m00.40s -25°46'01.4" * TYC 6541-2525-1 mV: 9.75 b-v: 2.11 mB:12.23 pmRA: 0.001 pmDE:-0.009

(cut and paste the above into notepad without word wrap it might then just be readable)

Seems to have components A through F and as indicated in a previous post there is nebulosity around too.

[renormalised (Carl)]

Here's the location of VY Canis Majoris.... I circled the star. Hope that helps. I used Starry Night to create the chart. Hope this helps.

[astroron (Ron)]

There was a discussion on Amastro, a Deep Sky Observers site, this object was called the "NIKE Swish"
It requires a medium to large scope and good seeing to resolve the nebula.
The star is very red, and quite noticable in a "fine star field"

[mikemasey (Mike)]

Thanks everyone, Ill get looking as soon as the moon has gone.

mike.