[vsnet-alert 2575] Nova Mus 98 - a possible periodicity

[Alon Retter <ar@astro.keele.ac.uk>]

Dear vsneters,

Photometry by William (Bill) Liller of Nova Mus 98 during ~4 hr in 27/1/99
through a 'broad' V filter (8-inch telescope) reveals a possible
photometric period of ~2.5 hr. The full peak amplitude is about 0.15 mag.
More observations are required in order to confirm this periodicity. The
nova is most probably in the transition phase. The physical mechanism that
causes these oscillations is still unknown. Among the possibilities, there
was a suggestion that these are oscillations of the common envelope. A
different suggestion is that they instabilities in the accretion disc
(similar to dwarf nova outbursts). If the period is confirmed, it means
that we see into the binary system, so the common envelope explanation
might be ruled out. In addition, if the white dwarf doesn't posses a
strong magnetic field, such a short period (which is probably the orbital
period) should be accompanied by a second superhump period, a few per
longer than the orbital period.

Any continuous run for more than ~2.5 hr in any filter (I is probably
preferred, clear is o.k., too) should be very useful.

I enclose below the data. Enjoy!

Regards,
Alon Retter
Keele University
===================
JD          dV
(-2451205)

.6116      .65
.6131      .76
.6165      .77
.6199      .81
.6234      .65
.6268      .70
.6302      .78
.6337      .66
.6371      .68
.6405      .62
.6440      .67
.6474      .69
.6508      .62
.6543      .61
.6577      .68
.6611      .74
.6646      .50
.6680      .67
.6714      .74
.6749      .67
.6783      .69
.6817      .68
.6852      .73
.6886      .70
.6920      .73
.6955      .70
.6989      .74
.7023      .76
.7058      .75
.7092      .72
.7126      .78
.7161      .66
.7195      .83
.7229      .72
.7263      .69
.7298      .73
.7332      .71
.7367      .68
.7401      .71
.7435      .68
.7470      .65
.7504      .70
.7538      .66
.7573      .71
.7607      .66
.7641      .65
.7676      .72

VSNET Home Page

Return to Daisaku Nogami

---

vsnet-adm@kusastro.kyoto-u.ac.jp