Results from the IBEX satellite indicate the nose of the solar system is pointing to the constellation Scorpius. Various sources say the solar apex is pointing to the constellation Hercules.

Are the two different, or is simply the information about the location in conflict?

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    $\begingroup$ I am not happy with the answer that I've given, specifically the first part with regards the quotes and references. As usual "all the good stuff" is behind a paywall of some sort or other. Clear definitions in the public domain would help the amateurs and those who wish to develop an interest and direct their energies. Possibly true for much of science, especially early education. $\endgroup$ Dec 9, 2018 at 3:53

1 Answer 1


Is the nose of the solar system and the solar apex the same thing?

No, they're roughly 60 degrees apart.

The Solar Apex.

The solar apex does indeed indicate a component of direction of travel within our corner of the galaxy:

The coordinates as obtained by visual observation of the apparent motion is right ascension 18h 28m 0s and declination of 30° North in galactic coordinates: 56.24° longitude, 22.54° latitude. The radioastronomical position is 18h 03m 50.2s and dec 30° 00′ 16.8″ galactic coordinates: 58.87° longitude, 17.72° latitude.

There are two different precise measurements here which conflict, I won't speculate as to why Wikipedia is unreferenced on the subject. The galaxy is a place containing a great deal of complex movement and the Local Standard of Rest is moving relative to the galactic plane, the centre of the galaxy and the other local stars:

In astronomy, the local standard of rest or LSR follows the mean motion of material in the Milky Way in the neighborhood of the Sun. The path of this material is not precisely circular. The Sun follows the solar circle (eccentricity e < 0.1 ) at a speed of about 255 km/s in a clockwise direction when viewed from the galactic north pole at a radius of ≈ 8.34 kpc about the center of the galaxy, and has only a slight motion, towards the solar apex, relative to the LSR.

We're traveling relative to an ever shifting cloud of stars towards Hercules (also shifting), southwest of the star Vega.

The sun's motion in the Milky Way is not confined to the galactic plane; it also shifts ("bobs") up and down with respect to the plane over millions of years.

So you see, there are many components of direction of travel to consider.

There's an unquotable abstract from a Harvard article here, which may give you an idea of how much needs to be taken into account in determining the relative vectors.

The Nose.

The ""Nose" of the solar system is sometimes used to refer to the direction of travel of the local galactic wind. Just as a comet's tail points away from the sun, the tail of the Heliopause points away from the wind, the nose points in the direction it's coming from.

enter image description here

The nose is as you have stated is pointing towards Scorpius.

  • $\begingroup$ so if i was looking in the direction of the center of the bow shock I would not necessarily be pointing in the direction of the solar apex? $\endgroup$
    – Bob516
    Dec 9, 2018 at 4:13
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    $\begingroup$ @Bob516 The, direction of the galactic wind is variable and chaotic. The trend is that it "blows" out from the central supermassive black hole's accretion disk, but since each moving star locally contributes to it, plus energetic events elsewhere within the galaxy, It's not easy to predict it's exact vector, especially since we don't have any extra-system observers. IBEX is the best we've got at present. $\endgroup$ Dec 9, 2018 at 4:32
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    $\begingroup$ @Bob516 Without getting into where you are in which hemisphere at what time of year. If you look out at the stars and you can pinpoint Hercules, you'll be roughly looking towards The solar Apex, if you want to look roughly at the nose then swivel south and look "down" by roughly 60 degrees. You will be out by a few degrees in both directions, because fall and spring places you at opposite sides of the sun and paralax gets a bit relevant. If you point yourself towards the constellations then you've seen in the right directions. $\endgroup$ Dec 9, 2018 at 5:04
  • $\begingroup$ that clears it up for me. I had assumed the galactic wind was directly correlated with the direction the solar system was going in the LSR (if I am getting that right). This is all for a science fiction story and I wanted to know the general direction one should point if looking towards the bow shock. Thanks. $\endgroup$
    – Bob516
    Dec 9, 2018 at 14:40

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