Context : The remarkable pre-main-sequence object V718 Per ( HMW 15 , H187 ) in the young cluster IC 348 periodically undergoes long-lasting eclipses caused by variable amounts of circumstellar dust in the line-of-sight to the star .
It has been speculated that the star is a close binary and similar to another unusual eclipsing object , KH 15D .

Aims : We have submitted V718 Per to a detailed photometric and spectroscopic study to investigate how regular the recurrent eclipses are , to find out more about the properties of the stellar object and the occulting circumstellar material , and to look for signatures of a possible binary component .

Methods : V718 Per was monitored photometrically from the optical to the near-infrared ( NIR ) .
We also obtained high-resolution optical spectra with the Keck telescope at minimum as well as at maximum brightness .
We derived the fundamental photospheric parameters of this star by comparing with synthetic spectra .

Results : Our photometric data show that the eclipses are very symmetric and persistent , and that the extinction law of the foreground occulting dust deviates only little from what is expected for “ normal ” interstellar material .
The stellar parameters of V718 Per indicate a primordial abundance of Li and a surface temperature of T _ { eff } \approx 5200 K. Remarkably , the in-eclipse spectrum shows a significant broadening of the photospheric absorption lines , as well as a slightly lower stellar surface temperature .
In addition , weak emission components appear in the absorption lines of H \alpha and the Ca II IR triplet lines .
We did not detect any signs of atomic or molecular features related to the occulting body in the in-eclipse spectrum .
We also found no evidence of any radial velocity changes in V718 Per to within about \pm 80 m s ^ { -1 } , which for an edge-on system corresponds to a maximum companion mass of { \sim } 6 ~ { } M _ { Jup } .

Conclusions : Our observations suggest that V718 Per is a single star , and thus very different from the related binary system KH 15D .
We conclude that V718 Per is surrounded by an edge-on circumstellar disk with an irregular mass distribution orbiting at a distance of 3.3 AU from the star , presumably at the inner disk edge .
To produce the prolonged eclipses , the occulting feature must extend along more than half of the inner disk edge .
The change in stellar surface temperature and the emission line activity observed could be related to spot activity .
We ascribe the broadening of photospheric absorption lines during the eclipse to forward scattering of stellar light in the circumstellar dust feature .