R Hydrae — Variable Star in Hydra
Showpiece (84/100)
Observe
1Physical Properties
Magnitude
4.97
Range
3.5 - 10.9
Period
359 days
Variable Type
Mira (Long-period Pulsating)
Spectral Type
M7IIIe
bright giant
Star Color
Red
(B-V 1.60)
2Position & Identifiers
RA
13h 29m 42.8s
Dec
-23° 16' 53.0"
Constellation
Hydra
(Hya)
HR
5080
HIP
65835
HD
117287
SAO
181695
Variable ID
R Hya
Double Cat
8920
Querying VizieR catalog...
3How easy to follow?
Magnitude
3.5 – 10.9 mag
Amplitude
7.4 mag
Period
359 d
Type
M
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| Equipment | Bortle 3 | Bortle 4 | Bortle 5 |
|---|---|---|---|
| Naked eye Naked eye | Imp. | Imp. | Imp. |
| 50 mm finder 50mm finder | Hard | V. hard+ | V. hard |
| 150 mm telescope 150mm scope | Medium+ | Medium+ | Medium |
Easy
Medium
Hard
Very hard
Impossible
Bortle 3 = rural · 4 = outer suburbs · 5 = suburbs
4Visibility
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Best season
Mar – May
(peak: Apr)
5Survey Image
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6Light Curve
7Comparison Stars for R Hya (3.5–10.9)
Nearby stable stars for estimating brightness (AAVSO)
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8
Size Comparison
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9
Compare Stars
10
Spectral Classification
11
Hertzsprung-Russell Diagram
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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
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16Stellar Notes
ADS 8920A, M 3.5 - 10.9v, 388.87d. Period varies; was 500d beginning of 18th century. M8 at minimum. Discovered by | Montanari in 1670.
Hyades group.
Technetium star. SiO maser emission. Also classified M6e-M9e.
Nearby in the Sky
Other targets within a few degrees — pan your scope a little and keep exploring.
Visibility scores assume a 150 mm Newton at Bortle 4.
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Article
Hydra
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Constellation
