SIMBAD references

We have analyzed high resolution spectra of several slightly to moderately reddened stars collected at two observatories: ESO (La Silla) and Terskol (Northern Caucasia), to estimate the abundance of the C₅ molecule in the interstellar medium. We confirm the presence of a feature near 4975Å which appears to be a weak DIB rather than the predicted C₅ band since the origin band near 5109Å remains invisible even in spectra of high signal-to-noise ratio (∼2500) and spectral resolution (R∼220000). This confirms that the C₅ abundance in translucent interstellar clouds is very low. We estimate its limit as low as 10¹¹cm^–2 in the scale E(B-V)=0.35 for ``zeta" type objects that is two times lower than that of Maier et al. (2002ApJ...566..332M).