Object X

CONFIRMED M33   Equatorial coordinates α =  23.350196 | 01 33 24.047000 δ =  30.426272 | +30 25 34.580000   Constellation Triangulum Symbiotic IR Type   Spectral Type yellow/red hypergiant + O-B Magnitude range (V)   Outbursts No

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Identifiers

Object X	GSC –	TYC –	WRAY –
SIMBAD 2MASS J01332404+3025345	HIP –	SAO –	Hen –
BD –	IRAS –	GAIA DR2 –	ESO –
HD –	2MASS J01332404+3025345	WISE J013324.03+302534.5	AAVSO –

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Position

Right ascension (°)	23.350196refKhan, R., Stanek, K. Z., Kochanek, C. S., et al., 2011, ApJ, 732, 43, 2011ApJ…732…43K	Parallax (mas)	–	Reddening E(B-V) (mag)	0.039 ± 0.001refSchlafly, E. F., Finkbeiner, D. P., 2011, ApJ, 737, 103, 2011ApJ…737..103S
Declination (°)	30.426272refKhan, R., Stanek, K. Z., Kochanek, C. S., et al., 2011, ApJ, 732, 43, 2011ApJ…732…43K	Distance (kpc)	847.00 ± 60.00refBonanos, A. Z., Stanek, K. Z., Kudritzki, R. P., et al., 2006, Astrophysics and Space Science, 304, 207, 2006Ap&SS.304..207B
Galactic longitude (°)	133.551679refKhan, R., Stanek, K. Z., Kochanek, C. S., et al., 2011, ApJ, 732, 43, 2011ApJ…732…43K	Proper motion in α (mas/yr)	–
Galactic latitude (°)	-31.578679refKhan, R., Stanek, K. Z., Kochanek, C. S., et al., 2011, ApJ, 732, 43, 2011ApJ…732…43K	Proper motion in δ (mas/yr)	–

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Observations

U (mag)	>24.1refKhan, R., Stanek, K. Z., Kochanek, C. S., et al., 2011, ApJ, 732, 43, 2011ApJ…732…43K	X-Ray		Flickering
B (mag)	>24.2refKhan, R., Stanek, K. Z., Kochanek, C. S., et al., 2011, ApJ, 732, 43, 2011ApJ…732…43K	X-Ray type		Outbursts	No
V (mag)	23.15refKhan, R., Stanek, K. Z., Kochanek, C. S., et al., 2011, ApJ, 732, 43, 2011ApJ…732…43K	IUE	No	Type
R (mag)	21.61refKhan, R., Stanek, K. Z., Kochanek, C. S., et al., 2011, ApJ, 732, 43, 2011ApJ…732…43K	IRAS flux at 12 μm (Jy)		IPmax (eV)	35.1refMikołajewska, J., Caldwell, N., Shara, M. M., et al., 2015, ApJ, 799, L16, 2015ApJ…799L..16M
I (mag)	19.99refKhan, R., Stanek, K. Z., Kochanek, C. S., et al., 2011, ApJ, 732, 43, 2011ApJ…732…43K	IRAS flux at 25 μm (Jy)		OVI lines	NorefMikołajewska, J., Caldwell, N., Shara, M. M., et al., 2015, ApJ, 799, L16, 2015ApJ…799L..16M
G (mag)		IRAS flux at 60 μm (Jy)
J (mag)	17.07refCutri, R. M., Skrutskie, M. F., van Dyk, S., et al., 2003, VizieR On-line Data Catalog: II/246, 2003yCat.2246….0C	IRAS flux at 100 μm (Jy)
H (mag)	15.04refCutri, R. M., Skrutskie, M. F., van Dyk, S., et al., 2003, VizieR On-line Data Catalog: II/246, 2003yCat.2246….0C	WISE W1 (mag)	11.95refCutri, R. M., et al., 2014, I II/328, 2014yCat.2328….0C
K (mag)	13.60refCutri, R. M., Skrutskie, M. F., van Dyk, S., et al., 2003, VizieR On-line Data Catalog: II/246, 2003yCat.2246….0C	WISE W2 (mag)	10.80refCutri, R. M., et al., 2014, I II/328, 2014yCat.2328….0C
L (mag)		WISE W3 (mag)	7.91refCutri, R. M., et al., 2014, I II/328, 2014yCat.2328….0C
		WISE W4 (mag)	5.30refCutri, R. M., et al., 2014, I II/328, 2014yCat.2328….0C
		Radio
		Radio flux (mJy)

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Orbit

Orbital period (days)	>10957500refMikołajewska, J., Caldwell, N., Shara, M. M., et al., 2015, ApJ, 799, L16, 2015ApJ…799L..16M	γ velocity (km/h)	-113refMikołajewska, J., Caldwell, N., Shara, M. M., et al., 2015, ApJ, 799, L16, 2015ApJ…799L..16M	Size of giant’s orbit (AU)
Eccentricity		RV of giant (km/h)		Separation (AU)
Inclination (°)		Inferior conj. of giant (JD)		Mass function
Ephemeris type				Mass ratio
Ephemeris T0 (JD)

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Cool component

Spectral type	yellow/red hypergiantrefKhan, R., Stanek, K. Z., Kochanek, C. S., et al., 2011, ApJ, 732, 43, 2011ApJ…732…43K	Mass (M⊙)	>30refKhan, R., Stanek, K. Z., Kochanek, C. S., et al., 2011, ApJ, 732, 43, 2011ApJ…732…43K	Pulsation
Eff. temperature (K)		Radius (R⊙)		Type
IR type		Luminosity (L⊙)		Pulsation period (days)
Metallicity [Fe/H]				Ephemeris type
				Ephemeris T0 (JD)

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Hot component

Type/Spectra	O-BrefMikołajewska, J., Caldwell, N., Shara, M. M., et al., 2015, ApJ, 799, L16, 2015ApJ…799L..16M	Mass (M⊙)	20-30refMikołajewska, J., Caldwell, N., Shara, M. M., et al., 2015, ApJ, 799, L16, 2015ApJ…799L..16M	Spin period (min)
Eff. temperature (K)		Radius (R⊙)		Accretion disk
Lower limit (K)	35000refMikołajewska, J., Caldwell, N., Shara, M. M., et al., 2015, ApJ, 799, L16, 2015ApJ…799L..16M	Luminosity (L⊙)	80000-160000refMikołajewska, J., Caldwell, N., Shara, M. M., et al., 2015, ApJ, 799, L16, 2015ApJ…799L..16M
Upper limit (K)	45000refMikołajewska, J., Caldwell, N., Shara, M. M., et al., 2015, ApJ, 799, L16, 2015ApJ…799L..16M

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Links

SIMBAD     CDS Portal

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Notes

The most luminous infrared star in M33. The star is clearly composite, with a hot, luminous O-B star component and a cool, dust-enshrouded companion. Object X is a very young and massive binary star (Mikołajewska et al., 2015).

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References

• Khan, R., Stanek, K. Z., Kochanek, C. S., et al., 2011, ApJ, 732, 43, 2011ApJ…732…43K
• Mikołajewska, J., Caldwell, N., Shara, M. M., et al., 2015, ApJ, 799, L16, 2015ApJ…799L..16M

Last updated: Jan 14, 2019 @ 9:21 am