3434 Hurless

Don Hurless

The asteroid 3434 Hurless was named after Carolyn Hurless, an AAVSO merit award winner with a lifetime total of 79,000 observations made from 1959 until her death in 1987. The asteroid was discovered in 1981 by B.A. Skiff at the Anderson Mesa Station of the Lowell Observatory. Carolyn's name was suggested by Paul Sventek who provided the citation. The following remarks are based on a letter David Cortner sent to me shortly after the name was assigned.

The asteroid will spend the fall of 1994 high in the constellation Taurus, well north of the ecliptic and perfectly placed for nothern hemisphere observers. At its brightest, between late October and early December, it will be no brighter than magnitude 16.4 to 16.0, but its position high in the clear winter sky may make up for some of its faintness. That year the asteroid and the Earth will pass within 124 million miles. The new moons of early November and December 1994 will provide the next best opportunity to pick the asteroid out. [I managed a pretty good photo of 3434 on Thanksgiving weekend, 1994, on Tech Pan from a suburban backyard. I'll post that photo when I can steal the time to prep it for the web. DC]

There will be one other opportunity to glimpse 3434 Hurless before the end of this century.

At the beginning of 1998, the asteroid will be both hidden by sunlight and lost among some of the richest star fields of the summer Milky Way. It will be near magnitude 18.4. Throughout spring, it will move north through Capricorn and Aquarius, gliding just south of the ecliptic. It will brighten to 17th magnitude as it and the Earth close from 320 million miles in January to 190 million miles in early summer. In mid-June, the asteroid enters the constellation Pisces as a 17th magnitude object. In early July it enters Cetus where it will remain for the rest of the year. By the time it enters Cetus, the asteroid will be 'only' 150 million miles from Earth. At magnitude 16.5, it will be within reach of very large amateur telescopes. By the end of July or by the beginning of August, 3434 Hurless will be brighter than 16th magnitude. It reaches perihelion during the first week of August and begins to withdraw from the Sun very slowly. The asteroid will continue to brighten as the Earth overtakes it in our faster orbit. On the last day of August, the asteroid begins retrograde motion. On September 18, the Earth draws within 100 million miles. Closest approach comes on the night of September 30 when the asteroid will be 98.5 million miles from Earth. The asteroid will then be between magnitude 15.5 and 15.0. It will be faint for the few weeks surrounding this date, but not hopelessly faint, just a nice inner sanctum kind of faint. It should be visible with care under dark skies with comparatively modest light buckets.

New moons (and darkest skies) occur around the 20th of each month from September through November 1998. One of those dark moons should offer our best chance to actually see 3434 Hurless. It will remain brighter than 16th magnitude until mid-November. Then, as it lags farther and farther behind the Earth, it will fade quickly through 17th to 18th magnitude by the end of the year.

For perspective, it is interesting to compare these favorable oppositions with a maximally favorable one. At the opposition of 1985, the first following its discovery, the then anonymous asteroid briefly reached magnitude 13.8 - 14.2, easily within reach of even modest telescopes under good skies. This is the brightest it has been since 1980 and the brightest it will be until at least 2018.

These notes about the physical characteristics of 3434 Hurless are based on comparisons of 3434 Hurless with other asteroids of similar absolute brightness, and therefore, presumably, of similar sizes. I know of no photometric studies or UBV measurements which could answer questions about the asteroid's composition or rotation and general shape. [In the years since these notes were written, acquiring this sort of data has become a perfectly reasonable project for CCD-equipped amateurs. DC]

In the absence of particulars, then, let us suppose 3434 is 15km (9.5 miles) in diameter. If mostly metallic (with an approximate density of 7 g/cm3), then its 450 cubic miles contain 13.7 trillion tons of nickel and iron. If stony, then it "weighs" about 5.5 trillion tons (assuming a density of 2.8 g/cm3). From the estimated size and these guestimated masses, we can infer the following physical characteristics.

The sorriest little league pitcher with the sorest of arms could casually toss a ball all the way around the asteroid (a distance of about 30 miles), and catch it an hour or two later or an hour or two after that on the ball's next orbit (or after its next, or its next, or its next...).

From 3434 Hurless the Earth is at most 16 arcseconds in apparent diameter and it is never nearly as bright a planet as Venus is as seen from the Earth. The Earth ventures about half as far from the Sun as Venus does for us. As seen from Hurless, our moon, several magnitudes fainter (a binocular object) is sometimes as far as 8.7 arcminutes from the Earth (about a third the apparent width of the Moon as seen from Earth). Mars and Jupiter are the brightest planets in the sky of 3434 Hurless. Jupiter is sometimes near enough that it's disk could be seen with the naked eye and at those times Jupiter shines about as brightly as Venus ever shines in the skies of Earth. Mars goes through phases as seen from 3434 and shines three or four magnitudes more faintly in the asteroid's sky than Venus does in ours.

Don has presented this material to various groups from time to time. I plan to update this version with photos made at the 1994 opposition near the Hyades, with some "light curves" showing the asteroid's brightness over the years, some maps, lots more numbers, and assorted other notes. Eventually, it would be nice to include UBV and photometric data to establish composition, rotation, and perhaps shape. DC