Does the loss of mass create an observable change in a comet's orbit?

Comets lose their mass through water evaporation due to close encounter with sun, so my question is does the loss of mass create an observable change in a comet's orbit? What kind of change that may be shrinking orbit or expanding orbit?

This problem was studied in Yu & Zheng (1995), who evaluated the effects of the change in the Sun's mass over time and the change in a comet's mass over time, for the case of Shoemaker-Levy 9, which had recently crashed into Jupiter. Given their mass model for the comet (Equation 6), they found that the Sun's mass loss created an increase in semi-major axis of about 8.5 centimeters per year, whereas the comet's mass loss created an increase in semi-major axis of about 10,000 kilometers per year.

Several things to note:

• The comet orbited Jupiter prior to breaking up, so it did not come as close to the Sun as most short-period comets.
• Mass loss rates can change over time, depending on the distance from the Sun.
• Shoemaker-Levy 9 should not be considered a normal comet, in any sense, given its orbit and eventual destruction.

10,000 kilometers a year, though, is nothing to sniff at. Over the course of an orbit, that can be quite a lot - although keep in mind that longer orbits involve much larger semi-major axes - and I'd argue that it should be observable, given the correct calculations of how the orbit should evolve over time.

• Your answer is good in its own but not as specific as i asked. What argument is right but you don't specifically mention that what kind of that change may be? My field is not astronomy so please bear with me. Commented Oct 1, 2016 at 7:44
• Why does comet orbit change? Because the mass loss is asymmetric? Commented Oct 1, 2016 at 15:56
• @ShujaatAliKhan The orbital parameter we're concerned with is the semi-major axis, one half the distance between the two furthest points in the elliptical orbit of the comet. It increases as the comet looses mass. Commented Oct 1, 2016 at 22:32
• @RobJeffries It turns out that the mass loss of the comet causes a tangential acceleration perturbation, coming from matter being blown off the comet at a constant velocity. Commented Oct 1, 2016 at 22:37
• So with every revolution a comet actually becomes more eccentric? That is interesting. If you wanted to cause the opposite and reduce the semi-major axis, I suppose you could 'block' the mass losses natural direction and only allow the opposite direction to be exposed to mass loss. Commented Sep 19, 2017 at 18:30