What?

• by Rob995

  Why if i do a search on NED about this object it is written "Helio. radial velocity: 385 233km/s PHOT"?

  Posted August 30, 2015 2:55 PM

• by Rob995

  Here the link: http://ned.ipac.caltech.edu/cgi-bin/objsearch?search_type=Obj_id&objid=52663251&objname=1&img_stamp=YES&hconst=73.0&omegam=0.27&omegav=0.73&corr_z=1

  Posted August 30, 2015 2:57 PM

• by williamaskew

  you are looking at the first in the list the SDSS object. you should be looking at NGC 3800

  Posted August 30, 2015 7:58 PM

• by Rob995

  Seemed just this... However, i think Einstein has something to say. 😄

  Posted August 30, 2015 9:09 PM

• by Budgieye moderator

  The radial velocity measures the apparent speed at which the galaxy is receding from us. The Helio. radial velocity has corrections for the movement of telescope during the Earth's rotation, and revolution around the Sun, (Helios, Greek god of the Sun) which will affect the measurement.

  http://www.astrosurf.com/buil/us/spe5/radv.htm

  The PHOT means that the software is guessing at the radial velocity, based on colour measurements. It can be right or wrong, but usually has huge error bars.

  Some info here

  PAGE 3 Spectra guide for SDSS images in Galaxy Zoo Talk http://talk.galaxyzoo.org/#/boards/BGZ0000001/discussions/DGZ0000ulp?page=3&comment_id=53fef2ee3d5a77490c0001b6

  Posted August 31, 2015 5:08 AM

• by Rob995

  Thank you! Is a world rich of things to know that of the astronomy 😃

  Posted August 31, 2015 9:31 AM

• by Budgieye moderator

  You're welcome 😃

  Posted August 31, 2015 9:09 PM