5 Notes on individual galaxies

UGC 288: The bright object near the center of the galaxy is very likely a foreground star, but the possibility of a nucleus cannot be ruled out, as the R-band brightness profile shows that the object is exactly at the center of the R-band isophotes of the outer parts. Therefore the object was not removed from the image.
UGC 685: This is a well-studied dwarf galaxy. Optical imaging has previously been carried out by Makarova et al. (1998) and Hopp (1999), where deep, high-resolution pictures are shown, and more recently by Jansen et al. (2000) and vanZee (2000). Makarova et al. (1998) and Hopp (1999) give a $B_{\rm T}$ (uncorrected for galactic absorption) of 14.44 and 14.55, respectively, while Jansen et al. (2000) and vanZee (2000) both give 14.20, which is in excellent agreement with our value of 14.22 (Table 2). However, our very blue colour of B-V = 0.24 (again uncorrected) is in strong disagreement with vanZee (2000) who gives B-V = 0.52, while, on the other hand, our B-R = 0.83 does agree with Jansen's (2000) B-R = 0.84and Hopp's (1999) B-R = 0.86. The B-R colour profile (Fig. 3) shows that the inner part of the galaxy, where several bright star forming regions are situated (Fig. 1), is indeed very blue, with $B-R \approx 0.5$. Morphology and colour made us reclassify this galaxy as Im/BCD, following Sandage & Binggeli (1984).
UGC 1281: Edge-on disk galaxy without any sign of a bulge. The bright, small elliptical object just to the left is the background galaxy VI Zw051. A better image is shown in Makarova et al. (1998). Independent photometry is provided by Makarova et al. (1998) and van Zee (2000). Our photometry, which is deemed uncertain by the colons in Tables 2 and 3, does not agree well with either of these studies. Our total blue magnitude ( $B_{\rm T} = 13.03$, uncorrected for galactic absorption) is significantly brighter than the values of 13.26 and 13.61 given, respectively, by Makarova et al. (1998) and van Zee (2000). There is a similar disagreement in the colours. However, the galaxy does appear fairly red, which is likely caused by the internal dust absorption of the highly inclined disk.
NGC 1156: The galaxy has many star forming regions. The brightest structure resembles a bar (therefore the classification of a IBm) and shows even rudiments of spiral arms. There are very many detailed studies of this galaxy (on its HII regions, CO content etc.), but none provide independent surface photometry, other than that given in the RC3.
UGC 2684: Very small and faint galaxy with a peculiar shape. Independent imaging provided by van Zee et al. (1997) whose $B_{\rm T} = 16.30$and B-V = 0.49 values are only in fair agreement with ours of $B_{\rm T} = 16.54$ and B-V = 0.77: (uncorrected for galactic extinction).
UGC 2689: In the NED this galaxy is listed with a heliocentric velocity of $v_{\rm hel}=277$ kms^-1, which would make it a nearby dwarf. However, in a study of the Perseus cluster of galaxies (Abell 426) by Brunzendorf et al. (1999), UGC2689 appears as a member of that cluster. There is indeed much in favour of the latter view. First, the morphological appearance of this galaxy is certainly S0-like. If the object were nearby, the small size and high surface brightness of its bulge would be unprecedented among dwarf galaxies (there is a class of "dwarf'' S0 galaxies, but these are not simply scaled-down versions of giant S0s, as they exhibit the low surface brightness typical of dwarf ellipticals, see Sandage & Binggeli 1984). Furthermore, the galaxy is quite red ( $B-R \approx$ 1) and shows a slight reddening inwards in the colour profile (see Fig. 3), which is well in accord with it being a normal giant S0 galaxy. It seems more likely, then, that the velocity listed is erroneous and that we deal with a background galaxy here.
UGC 2716: The star-forming region of high surface brightness is clearly off-centered with respect to the "underlying'', more extended low-surface-brightness part of the galaxy.
UGC 2905: Peculiar shape. The galaxy appears in the catalogue of the Pisces-Perseus Supercluster (Giovanelli et al. 1993) where indeed a heliocentric velocity of $v_{\rm hel}=293$ kms^-1 is reported. Unlike UGC2689, this is a "well-behaved'' dwarf galaxy (in terms of morphology and colour) that happens to be projected into the sky area of a background cluster.
UGC 3303: Large disk galaxy behind a sprinkle of foreground stars, all of which had to be cleaned away for the photometry. Unfortunately, a very bright star lies close to the center of the galaxy. For a better image see Makarova et al. (1998). There are clear signs of spiral arms and some structure in the central area (a nucleus?). The negative colour gradient (inward reddening, Fig. 3) is in accord with the spiral (disk) nature of the galaxy.
PGC 17716: This object, an intrinsically fairly large and bright disk galaxy, also named "Orion'', is lying deep in the zone of avoidance and suffers a huge galactic absorption of A_B = 3.17. The apparently extreme blue colour ( B-V = 0.07) is probably influenced by the strong correction for galactic extinction. A deep, high-resolution image is shown in Karachentsev & Musella (1996), who also carried out the first optical study of this galaxy. Their $B_{\rm T}$ estimate of 15.7 is in good accord with our value of 15.41 (uncorrected for galactic extinction). According to Karachentsev & Musella (1996), this galaxy, together with UGC 3303 and A0554+07, may belong to a loose galaxy group (the "Orion group'') that is still largely hidden in the zone of avoidance.
A0554+07: Very faint and highly obscured galaxy ( A_B = 2.56). Superior image shown in Karachentsev & Musella (1996). Associated with PGC 17716; see note on that galaxy.
UGC 3476: Very peculiar shape. Excellent image shown in Makarova & Karachentsev (1998). Very steep colour gradient (see Fig. 3).
UGC 3600: Flat brightness profile and almost no colour gradient. The galaxy looks very smooth, almost dE-like, even on the deep image provided by Makarova & Karachentsev (1998).
Kar 49: Faintest galaxy in the sample; could be a dwarf elliptical.
NGC 2337: Bright galaxy with several knotty star-forming regions, of BCD morphology. Very deep image shown in Makarova & Karachentsev (1998), whose $B_{\rm T}$ of 13.10 is mildly discordant with ours (13.48, uncorrected for galactic extinction).
Kar 50: Blue galaxy with spherical shape and almost constant surface brightness.
UGC 4115: Smooth brightness profile (only B available). Bright foreground star was erased.
NGC 2537: Very bright star-forming regions which seem to form a partial ring. BCD morphology.
DDO 64: Well studied dwarf galaxy. Deep, high-resolution pictures shown in Hopp & Schulte-Ladbeck (1995) and Makarova & Karachentsev (1998). Our uncorrected $B_{\rm T} = 15.40$ for this galaxy is strongly discordant with Makarova & Karachentsev's (1998) value of 14.45, while there is perfect agreement on B-V at 0.30. The reason for the discrepancy in $B_{\rm T}$ is unclear. We note, however, that part of the problem may be due to the erroneous inclusion of two bright foreground stars (see image) in the total magnitude by Makarova & Karachentsev (1998). The value listed in the RC3, which is based upon aperture photometry where all foreground stars are included automatically, is too bright (14.41) as well (cf. Sect. 4.4).
DDO 97: Higher B-R in the central area (see Fig. 3) where also a small star-like object is visible (nucleus?). The outer parts show some signs of spiral arms. Otherwise of smooth, almost dE-like appearance. For a deeper image see Makarova et al. (1998). Fair agreement between our photometry and that of Makarova et al. (1998): $B_{\rm T} = 15.20$ versus 15.39 and B-V = 0.59 versus 0.67 (not corrected for galactic extinction), respectively. Makarova et al. (1998) estimate a distance of 14 Mpc, which, if true, would place the galaxy in the outskirts of the Virgo cluster.