symbiotic nova J17460t0-2321.3 Campaign

[Francois Teyssier]

I foreward an AAVSO notice about the symbiotic nova J17460t0-2321.3
At mag ~ 12, it is a excellent target for low resolution spectroscopy.
The star should be observed from now to at least august (good target for OHP
Meeting !)

Of course, I open a page in ARAS data base

Send spectra to francoismathieu.teyssier@bbox.fr

format : _asas_j174600-2321_aaaammdd_hhh_obersername.it

Refrence star

I propose
HD 158643 RA 17 31 25.0 DE - 23 57 45.5 V = 4.81 B-V = 0
E(B-V) = 0.01 A0V

All the best,

François Teyssier

Subject: AAVSO Alert Notice #510: Observations of the symbiotic nova ASAS
J174600-2321.3

The AAVSO is requesting observations of the symbiotic nova candidate
ASAS J174600-2321.3 during the predicted upcoming eclipse of this system.
Observers are asked to begin observing immediately (2015 March 5), and
continue observations through the end of July 2015. Both visual and
instrumental observations are encouraged; the object was at V=12.28 on
2015 February 6.764 (OCN; S. O'Connor, Bermuda). Filtered, transformed
photometry in B, V, and Ic are especially encouraged, with several
observations per night required during the ingress and egress phases.
The project is being organized by S. Otero, P. Tisserand, K. Bernhard,
and S. Hummerich, and is an extension of the research program discussed
in Hummerich et al. (2015, eJAAVSO #295, in press).

The researchers have provided the following discussion of the project:

"The deeply eclipsing system and likely symbiotic nova ASAS J174600-2321.3

RA: 17 46 00.18 , Dec: -23 21 16.4 (J2000.0)

is going to enter an eclipse in mid-March according to the published
elements
HJD = 2456142 + 1011.5 × E. The eclipse duration is approximately 115 days.

The system has shown a conspicuous brightening of ~4 magnitudes (V) that
started in 1999 and has been in outburst since then. Recent photometry shows
the system fluctuating around 12.2 mag (V) as recently as 2014 November 07
(JD 2456969.49068; HMB, J. Hambsch, Mol, Belgium, remotely from Chile). It
will go fainter than 16.9 mag (V) at mid-eclipse when the red giant passes
in front of the outbursting white dwarf. We might also be seeing
semi-regular
pulsations from the red giant during eclipse.

As no observations around mid-eclipse exist after the considerable
brightening
of the primary star, the exact shape of eclipse is open to conjecture. Thus,
no times of second or third contact are given below, although there was a
pronounced time of totality during the eclipse that has been covered before
the onset of activity in the system (compare Fig. 4, JAAVSO #295).

We encourage visual and CCD observations during the eclipse, preferably
multicolour photometry to record the colour changes as the red star starts
to
dominate the total flux of the system. Observations in V, B and Ic would be
very valuable (note, though, that the object will be very faint in B during
eclipse). During the ingress and egress phases, several observations per
night
are advisable. During the remainder of the eclipse, one set of observations
per night will be adequate due to the long period of the system. Stacking
might be advisable to reach the faint magnitudes during the eclipse.

Observations should start as soon as possible to check on the brightness of
the object before the eclipse sets in. Once the event is over, continued
photometry with a cadence of one observation per week is encouraged to
detect
the start of the fading phase of this very slow nova.

Spectroscopic observations near mid-eclipse would be very desirable, too.

These are the dates observers should keep in mind:

1st contact: 2015 March 14 (JD 2457096)
Mid-eclipse: 2015 May 11 (JD 2457153.5)
4th contact: 2015 July 07 (JD 2457211)

The start and end of the eclipse may vary so please be patient if the
eclipsedoesn't start at the predicted date!"

This AAVSO Alert Notice was prepared by S. Hummerich and collaborators, with
assistance from M. Templeton.

[Joan Guarro Flo]

Hi all:

The graph is very schematic, only the result of two integrations of 1000 seconds.

The star of comparison, HD158643, shows activity in the Halpha.

J.Guarro

[Robin Leadbeater]

The star of comparison, HD158643, shows activity in the Halpha.

Yes HD158643 (51 Oph) is classified by Gray and Corbally as an Ae star (A0 II-III(e) table 1 here)
http://cdsbib.u-strasbg.fr/cgi-bin/cdsb ... .116.2530G
It might be worth checking it against a MILES star or similar to be sure the continuum is typical of an A0v

Robin