Save for its apparent size of about 0.3 by 0.2 arcmin, nothing seems to be known about NGC 7551. This is probably due to what appears to be considerable confusion about the actual galaxy corresonding to this entry. An NED search for NGC 7551 lists the position above, and states that the galaxy is PGC 70791. But LEDA gives a position for PGC 70791 which is identical to PGC 70788, which is NGC 7540, and as a result every other search result I've seen for NGC 7551 shows NGC 7540, instead. However, I should perhaps say that mirror sites for LEDA give the above result, as LEDA itself has been offline for a week, and I haven't been able to check it. In any event, there is a obviously a serious error somewhere, which I hope to clear up in the next iteration of this page.

A member of the Grus Quartet of spiral galaxies (NGC 7552, 7582, 7590 and 7599, as shown in the images below). Based on a recessional velocity of 1610 km/sec, NGC 7552 is about 75 million light years away, in reasonable agreement with redshift-independent distance estimates of 55 to 70 million light years. Given that and its apparent size of 3.4 by 2.7 arcmin, it is about 75 thousand light years across. Two of the four members of the Grus Quartet are also listed as members of a group of galaxies in (or near) Sculptor with recessional velocities of about 1500 to 1800 km/sec (this is not "the" Sculptor Group, a close neighbor to our Local Group, with an average recessional velocity of less than 300 km/sec); so all of the Grus Quartet members are presumably also members of the larger group.

Apparent size about 0.4 by 0.4 arcmin.

Apparent size about 0.4 by 0.4 arcmin. Apparently located in the halo of NGC 7556, which see for images.

Probably a misrecorded observation of NGC 7515, 7536, 7559, 7563, or 7570

Apparent size about 2.5 by 1.6 arcmin.

Apparent size about 0.3 by 0.2 arcmin. Apparently located in (or in front of) the halo of NGC 7556, which see for images. However, in the absence of other data, although "NGC 7556A" is probably located in the same cluster as NGC 7556, the galaxies may not be as close as they appear.

"preceding of 2". Apparent size about 0.6 by 0.6 arcmin.

Not an NGC object, but often called NGC 7559B because of its apparent proximity to NGC 7559, which see for images. Too faint for Herschel to have seen, so not part of a multiple-galaxy entry. Apparent size about 0.3 by 0.2 arcmin.

Not an NGC object, but often called NGC 7562A because of its proximity to NGC 7562. Apparent size about 1.5 by 0.4 arcmin.

Per Dreyer, NGC 7578 (= John Herschel's GC 4926, 1860 RA 23 10 14, NPD 72 04.3) is "very faint, among very small stars". The description is due to John Herschel; his father William only noted "faint". The position is not good enough to tell which of the two galaxies Herschel observed; the most commonly used A/B labels are (as shown above) in order of their right ascension, not in order of brightness, which is about the same. "B" is a more intense point of light (having the same brightness in a smaller area, as stated below), so that may be what Herschel noticed; but keeping in mind the limit of brightness and resolution two hundred plus years ago, odds are that he saw the combined light of the pair. PGC 70933 (NGC 7578A, per the listing above) is about 0.8 by 0.8 arcmin, and PGC 70934 (NGC 7578B) is about 0.4 by 0.4 arcmin.

The second IC lists a corrected NPD (per DeLisle Stewart) of 133 07 and notes that Herschel made only one observation. A member of the Grus Quartet of spiral galaxies (NGC 7552, 7582, 7590 and 7599; see image of all four at NGC 7552). Based on a recessional velocity of 1575 km/sec, NGC 7582 is about 75 million light years away, in reasonable agreement with redshift-independent distance estimates of 55 to 65 million light years. Given that and its apparent size of 5.0 by 2.3 arcmin, it is about 100 thousand light years across. Two of the members of the Grus Quartet are also listed as part of a group of galaxies in or near Sculptor with recessional velocities of about 1500 to 1800 km/sec (this is not "the" Sculptor Group, a close neighbor to our Local Group with an average recessional velocity of less than 300 km/sec); so all the Grus Quartet galaxies are presumably members of the larger group.

A member of the Grus Quartet of spiral galaxies (NGC 7552, 7582, 7590 and 7599; see image of all four at NGC 7552). Based on a recessional velocity of 1575 km/sec, NGC 7590 is about 75 million light years away, in good agreement with redshift-independent distance of 60 to 90 million light years. Given that and its apparent size of 2.7 by 1.0 arcmins, it is about 60 thousand light years across. NGC 7590 is listed as a member of a group of galaxies in (or near) Sculptor with recessional velocities of about 1500 to 1800 km/sec (this is not "the" Sculptor Group, a close neighbor to our Local Group, with an average recessional velocity of less than 300 km/sec); so all Grus Quartet members are presumably members of the larger group.

Based on a recessional velocity of 10850 km/sec, a straightforward calculation indicates that NGC 7594 is about 505 million light years away. However, for objects at such distances, we must take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 485 million light years away (in reasonable agreement with redshift-independent distance estimates of 360 to 460 million light years) at the time the light by which we see it was emitted, about 495 million years ago (the difference between the distance and the light-travel time being due to the expansion of the intervening space during that time). Given its distance and an apparent size of 1.4 by 0.9 arcmin, NGC 7594 is about 200 thousand light years across. (Note: A Wikisky search for IC 1478 shows IC 1478 (labeled as such), but a search for NGC 7594 shows IC 5306 (incorrectly labeled as NGC 7594). This is probably due to historical confusion about the identity of NGC 7594, which will be addressed in the next iteration of this page.)

A member of the Grus Quartet of spiral galaxies (NGC 7552, 7582, 7590 and 7599; see image of all four at NGC 7552). Given a recessional velocity 1650 km/sec, NGC 7599 is about 75 million light years away, in good agreement with redshift-independent distance estimates of 60 to 75 million light years. Given that and its apparent size of 4.4 by 1.3 arcmin, it is about 100 thousand light years across. NGC 7599 is listed as a member of a group of galaxies in (or near) Sculptor with recessional velocities of about 1500 to 1800 km/sec (this is not "the" Sculptor Group, a close neighbor to our Local Group, with an average recessional velocity of less than 300 km/sec); so all Grus Quartet members are presumably members of the larger group.