27 Leonis Minors is one of the least variable stars in the Hipparcos catalog. It is included in the "Research Note. Hipparcos photometry: The least variable stars." which lists the least variable stars found in the catalog. This list was was published in 2001 (Adelman S. J.).
This star is also considered to be a suitable calibrator star for modern optical inferometers and is included in "A catalog of calibrator stars for next-generation optical interferometers." This is a list of stars that are suitably bright and meet a number of other requirements necessary to qualify as optical calibration stars.
The bright orange star to the lower left of 27 Lmi is 28 Leonis Minoris. This is an oranged-hued giant star of spectral type K1III.
The star is moderately bright at magnitude 5.5 and is 146.5631 parsecs (478 light years) away.
Similar to 27 LMi, 28 Leonis Minoris is also a suitable calibration star. "A catalog of bright calibrator stars for 200-m baseline near-infrared stellar interferometry. (2005, Merand A., Borde P. and Coude du Foresto V.)" includes this star along with 947 others that are useable for calibrating near-infrared interferometry equipment.
The SIMBAD database shows that UU LMi is a long period variable star with a spectral type of M6III. It is magnitude 7.03 and binoculars are necessary to view this star.
HD 90024 is a magnitude 7.08 K0 type star and is even less visible than UU LMi. As we can see from the image, these two stars shine with a similar orange hue and at a similar brightness.