NGC 1262 in Eridanus

[Mike JW]

NGC 1262 in Eridanus is a distant galaxy. It lies about 2 billion lyrs away (Sky Safari) . Noting how big it is in my shot, it is enormous. - 474,000 lyrs across. It is a  SABc spiral (an intermediate spiral).

Tricky for me to get a shot of this galaxy as it is low down and in the murk.  I was so pleased to see it on the screen I forgot to tweak the mount to get it in the centre of the fov.

 

[Craney]

Nice one Mike.  I don't think I can see Eridanus from my garden due to the neighbourhood, and a nicely placed used-car lot with hyper bright halogens.

I do like a galaxy with something unusual about it.

[Bill S]

Yes indeed a nice one. I see that Wikipedia says it's the most distant object of the New General Catalogue. So another good reason to have a look at it.

[Mike JW]

Hi Bill, thanks for the info. I had not realised that fact. I have been trying to understand distances to objects - nightmare stuff - Hubble Constants, galaxies moving towards each other within a cluster whilst generally moving away from. The Medieval View of the heavens was much easier to grasp!!!!!!

SkySafari says 2 billion lyrs away but my list says 1.5 billion. Looking at the NED data got very confusing but I think NED is suggesting about 1.6 billion.

Mike 

[Martin Meredith]

Nice shot! LEDA gives about 1720 million LYs. LEDA also suggests there are NGCs that are further away but I don't necessarily trust all this data. This is a list ordered by distance.

[Mike JW]

Hi Martin,

Interesting data. I have just spent time on LEDA and got very confused. I shall do some more investigating when time permits. Mike

[Martin Meredith]

Hi Mike

In LEDA distances are given in some other type of unit and need to be converted using something like this:

Dist = round(3.261633 * power(10,(modz-25)/5));  % in LY

where modz is in the units LEDA uses for distance

Martin

 

[Mike JW]

Hi Martin

Thanks for the equation - I don't understand it (maths never a strong point) - any chance of a worked example? but only if you have time.

I tried looking up the meaning of modz/units and got nowhere.

Mike

40 minutes later....

PS. Just found this table on VizieR - https://vizier.u-strasbg.fr/viz-bin/VizieR?-source=VII/275. I inputted NGC 1262 and then looked at the column for distance in Mpc and then x 3.26lyrs, which gives a distance of 1.719 billion lyrs away. This matches your info for 1262. This is easier for me than your equation!!

Edited January 25, 2020 by Mike JW
more information found

[Martin Meredith]

Hi Mike

As I understand it this is a way of expressing distances in terms of the magnitude the object would be if seen at a fixed distance of 10 parsecs. So an object with a distance modulus of 0 would be at 10 parsecs, one whose distance modulus is -1 would be closer, and one with modulus 1 would be further away. Like magnitudes, these are based on a logarithmic scale, meaning we can use relatively small numbers to maintain precision while accommodating vast distances. Since it is a log scale, to convert back to real distances one has to raise to a power (the inverse of logarithm). The actual formula used in LEDA (as I give above) is explained here:  http://leda.univ-lyon1.fr/a007/index.html

See also explanation of distance modulus here: https://astro.unl.edu/naap/distance/distance_modulus.html and https://lco.global/spacebook/distance/what-is-distance-modulus/

HTH!

Martin

[Mike JW]

Thanks Martin - looking forward to some serious brain work.

Started down loading the Pretty Deep Sky maps - takes an age but looks some very useful charts.

Mike

[Bill S]

Or another place to look to get a similar but slightly smaller distance is

https://ned.ipac.caltech.edu/byname?objname=NGC 1262&hconst=67.8&omegam=0.308&omegav=0.692&wmap=4&corr_z=1

509.06 MPc 1660 Mly It's definitely a long way.