2015A&A...584A..21A


Query : 2015A&A...584A..21A

2015A&A...584A..21A - Astronomy and Astrophysics, volume 584A21-21 (2015/12-1)

First X-ray detection of the young variable V1180 Cassiopeiae.

ANTONIUCCI S., NUCITA A.A., GIANNINI T., LORENZETTI D., STELZER B., GERARDI D., DELLE ROSE S., DI PAOLA A., GIORDANO M., MANNI L. and STRAFELLA F.

Abstract (from CDS):

V1180 Cas is a young variable that has shown strong photometric fluctuations (ΔI∼6mag) in the recent past, which have been attributed to events of enhanced accretion. The source has entered a new high-brightness state in September 2013, which we have previously analysed through optical and near-infrared spectroscopy. To investigate the current active phase of V1180 Cas, we performed observations with the Chandra satellite aimed at studying the X-ray emission from the object and its connection to accretion episodes. Chandra observations were performed in early August 2014. Complementary JHK photometry and J-band spectroscopy were taken at our Campo Imperatore facility to relate the X-ray and near-infrared emission from the target. We observe a peak of X-ray emission at the nominal position of V1180 Cas and estimate that the confidence level of the detection is about 3σ. The observed signal corresponds to an X-ray luminosity LX(0.5-7keV) in the range 0.8/2.2x1030erg/s. Based on the relatively short duration of the dim states in the light curve and on stellar luminosity considerations, we explored the possibility that the brightness minima of V1180 Cas are driven by extinction variations. From the analysis of the spectral energy distribution of the high state we infer a stellar luminosity of 0.8-0.9L☉ and find that the derived LX is comparable to the average X-ray luminosity values observed in T Tauri objects. Moreover, the X-ray luminosity appears to be lower than the X-ray emission levels around 5x1030/1x1031erg/s detected at outbursts in similar low-mass objects. Our analysis suggests that at least part of the photometric fluctuations of V1180 Cas might be extinction effects rather than the result of accretion excess emission. However, because the source displays spectral features indicative of active accretion, we speculate that its photometric variations might be the result of a combination of accretion-induced and extinction-driven effects, as suggested for other young variables, such as V1184 Tau and V2492 Cyg.

Abstract Copyright: ∼

Journal keyword(s): stars: individual: V1180 Cas - stars: pre-main sequence - stars: variables: T Tauri, Herbig Ae/Be - X-rays: stars - X-rays: individuals: V1180 Cas - stars: activity

Simbad objects: 9

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Number of rows : 9
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2026
#notes
1 LDN 1340 DNe 02 30 40 +72 57.3           ~ 35 0
2 V* V1180 Cas Or* 02 33 01.5361317744 +72 43 26.807653884 22.476 21.433 19.280 18.029 16.878 K7 26 0
3 2MASS J02330247+7243315 Y*O 02 33 02.473 +72 43 31.56           ~ 6 0
4 V* V1118 Ori TT* 05 34 44.7401295035 -05 33 42.119715628 15.053 15.378 14.430 15.22 12.701 M1e 153 0
5 V* V1647 Ori Or* 05 46 13.1370578472 -00 06 04.885093296     18.1     M3.9 317 1
6 V* V1184 Tau Or* 05 47 03.7742454720 +21 00 34.786359684       14.66   G5III/IVne 42 0
7 V* Z CMa Ae* 07 03 43.1599411656 -11 33 06.209065836 10.51 9.99 8.80     B5/8eq+F5/7 601 3
8 V* V2492 Cyg Or* 20 51 26.2367188536 +44 05 23.869354488   20.2   18.3   F-GII/MI 107 0
9 V* V2493 Cyg Or* 20 58 17.0280367392 +43 53 43.341681156   19.678 18.023 17.67 15.233 M4.6 139 0

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