When is the best time to observe V509 Cassiopeiae?

V509 Cassiopeiae is best observed from August through October, with peak visibility during September when it transits around midnight in the Northern Hemisphere.

Where is V509 Cassiopeiae located in the sky?

V509 Cassiopeiae lies in the constellation Cassiopeia at right ascension 23h 00m and declination +56° 57′.

What telescope do I need to follow V509 Cassiopeiae?

To follow V509 Cassiopeiae through its full brightness cycle (magnitude 4.8 to 5.5) you need the naked eye under a dark sky — the star fades out of smaller apertures near minimum light.

V509 Cassiopeiae — Variable Star in Cassiopeia

Observable Variable Star Excellent (62/100)

Range: 4.75 - 5.38, Period: 175.0d, Type: YHG

Magnitude 4.8–5.5^m VariableStar Cassiopeia (Cas) Visible

Star Map + List + Plan

Observe

1Physical Properties

Magnitude 5.00

Range 4.75 - 5.38

Period 175 days

Variable Type Yellow Hypergiant

Spectral Type G40

Star Color Yellow (B-V 1.42) (reddened by dust)

Distance 1,631 ly

2Position & Identifiers

RA 23h 00m 05.1s

Dec +56° 56' 43.0"

Constellation Cassiopeia (Cas)

HR 8752

HIP 113561

HD 217476

SAO 35039

Variable ID V509 Cas

SIMBAD

3How easy to follow?

Magnitude 4.8 – 5.5 mag Amplitude 0.8 mag Period 175 d Type YHG

Sign in and configure your equipment and default location to see a personalized row.

Equipment	Bortle 3	Bortle 4	Bortle 5
Naked eye Naked eye	Hard	Hard	V. hard+
50 mm finder 50mm finder	Medium	Medium	Medium
150 mm telescope 150mm scope	Medium	Medium	Medium

Easy Medium Hard Very hard Impossible

Bortle 3 = rural · 4 = outer suburbs · 5 = suburbs

4Visibility

Set a location in User Settings to see visibility data.

Best season Aug – Oct (peak: Sep)

5Survey Image

Loading survey image…

6Light Curve

7Comparison Stars for V509 Cas (4.8–5.5)

Nearby stable stars for estimating brightness (AAVSO)

Loading comparison stars…

Explore

8

Size Comparison

Querying VizieR for stellar data…

9

Compare Stars

Compare with another star

10

Spectral Classification

11

Hertzsprung-Russell Diagram

Loading HR diagram…

Read: The Hertzsprung-Russell Diagram — Reading Stars Like a Map

12

Stellar Lifecycle

13

Blackbody Spectrum

14

Stellar Absorption Spectrum

Simulated absorption spectrum based on spectral type. Hover over lines to identify elements.

15

Stellar Fusion

Discover

16Stellar Notes

Variable Star

SRd 4.75 - 5.50V. Spectrum variable. Variable NII emission. Probable nonradial pulsations coupled with mass loss. | Phase between V and B-V curves changed between 1980 and 1985, from half phase out of cycle to in phase. Cycles on | time scale of about a year. Bimodal radial pulsation inferred (Sheffer and Lambert 1987, PASP, 99, 1277) from analysis | of a decade of spectroscopic observations. As opposed to remarks on spectral type, the star appears to be getting | bluer (IBVS 3170), implying an increase in temperature of 800 K over the past decade.

Group/Cluster

Cep OB1.

Spectral

Formerly classified G0Ia, but is intrinsically considerably brighter. Also classified F8e-KIa + BIV. According to | Morgan and Keenan (1973, ARA&A, 11, 29) spectrum has varied slowly from G0 0 to G5 0 over the last 20 years.

17