first rscvn commit

config.defaults.yaml

@@ -231,6 +231,15 @@ docs:
     variable:
       coordinates: [ 102.5537728, 44.1032507 ]
       title: Variable stars
+    rs_cvn_1:
+      coordinates: [344.8924,6.1829]
+      period: 2.834970
+      title: RS CVn
+    rs_cvn_2:
+      coordinates: [349.1745,36.5569]
+      period: 5.900631
+      title: RS CVn with modulation
+
 
 features:
   phenomenological_d12:

data/golden/rs_cvn.csv

@@ -0,0 +1,91 @@
+ra,dec
+116.5460,29.4144
+106.1385,36.1189
+202.5821,29.0948
+118.4703,21.1640
+212.1741,-8.4681
+260.7941,22.0534
+321.8671,7.7000
+13.5716,2.4428
+107.7544,54.8618
+127.7441,6.7789
+115.1254,24.9292
+112.0675,30.5794
+14.9901,30.8278
+29.1911,32.6006
+108.8383,28.2651
+220.4281,15.0601
+110.7043,34.5766
+32.9781,-12.9502
+118.8534,12.5069
+100.1043,57.4237
+35.0531,14.6167
+17.8315,-9.4326
+113.3872,34.2356
+45.6811,20.2800
+257.2931,54.4960
+5.4266,38.2104
+114.6323,35.7114
+113.9801,32.2946
+123.2301,2.9129
+110.4553,30.0514
+255.2221,36.9997
+247.8471,-2.2064
+224.7341,-10.9800
+242.5281,6.9274
+261.3541,40.0359
+128.1971,10.8852
+53.0791,-3.5412
+239.8731,25.3449
+201.5471,-5.4531
+102.7434,34.3382
+39.0661,38.3869
+21.5161,-12.1272
+38.9121,39.0369
+244.7741,0.0124
+110.6667,33.1876
+131.3171,2.4905
+108.1823,41.2532
+240.2661,14.9707
+113.6721,49.7235
+331.4371,21.8907
+101.7798,44.6628
+247.0821,37.3663
+101.6630,61.3512
+216.4391,-0.4998
+110.1130,40.7817
+118.1008,36.6713
+116.3274,31.2897
+15.6330,16.0505
+218.8711,-17.8939
+110.2710,41.7037
+41.3581,10.2480
+0.2640,10.9568
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+118.8351,14.8517
+109.4087,35.9424
+108.9465,53.8810
+18.4741,37.9520
+108.3139,45.5459
+17.2413,-13.3874
+105.3045,52.5338
+131.3311,20.0841
+51.9181,20.1754
+16.7225,35.5003
+102.5070,43.5569
+11.9440,20.4947
+10.0162,30.0036
+37.2301,4.5752
+56.1241,29.9870
+18.0916,29.8321
+41.6891,0.1590
+141.6521,25.6570
+113.7695,20.5859
+15.7480,32.8324
+264.6621,36.0267
+48.1291,-3.1162
+115.2033,44.1012
+115.2155,26.7927
+42.5701,17.1515
+113.1125,43.0799
+230.0761,-12.1313

doc/field_guide.md

@@ -35,3 +35,6 @@ for more details on the taxonomy.
 
 ```{include} ./field_guide__lpv.md
 ```
+
+```{include} ./field_guide__rs_cvn.md
+```

doc/field_guide__rs_cvn.md

@@ -0,0 +1,49 @@
+## RS CVn (rscvn)
+
+
+### Classification and numbers
+- Supertypes
+  - variable
+  - periodic
+  - binary
+- Occurrence rate: common, about 10<sup>5</sup> expected in ZTF data
+
+
+### ZTF light curves
+![ZTF rscvn](data/rs_cvn_1.png)
+![ZTF rscvn flaring](data/rs_cvn_2.png)
+
+#### Description
+RS Canum Venaticorum stars are binary systems in which one or both stars are chromospherically active. The surface of the star (typically F or G main-sequence or subgiant) is covered with groups of spots, which makes the surface brightness inhomogenious. These spots rotate with a period close to the orbital period. However, the spot rotation period can differ slightly from the orbital period, which causes the lightcurve shape to change over timescales of years. The variability of the wave's amplitude is explained by the existence of a long-period stellar activity cycle similar to the 11-year solar activity cycle, during which the number and total area of spots on the star's surface vary. Small amplitude flares, another signature of chromospheric activity, can also be observed in some cases.
+
+Other types of variable stars with chromospheric activaty (which we do not consider of the RS CVn type):
+- white dwarf or hot subdwarf stars with a chromospherically active companion
+- BY Dra variables (single rotating star, typically K or M type)
+- UV Cet variables (flaring low mass main sequence stars)
+- single solar-type stars with active chromospheres
+- T Tau variables (young chromospherically active stars)
+- W UMa binaries (overcontact binaries)
+- FK Com stars (rapidly rotating single stars)
+- single giants with active chromospheres
+
+#### Light curve characteristics
+- periodic variable
+- period range: 0.5-50 days
+- amplitude: 0.01 up to 0.6 mag
+- light curve shape:
+    - sinusoidal; or with two maximima and minima of different heights and depths
+    - the shape can change over timescales of years (modulation)
+    - they can show eclipses, but this is not required
+    - can show stellar flares
+
+
+#### Other characteristics and selection methods
+- the chromospherically active star is a F or G main-sequence star
+- often show Ca-II emission lines
+
+![HR diagram of RS CVn](data/hr__rs_cvn.png)
+![RA/Dec diagram of RS CVn](data/radec__rs_cvn.png)
+
+### References and further reading:
+- VSX: https://www.aavso.org/vsx/index.php?view=about.vartypes
+- Sterken & Jasschek: Light curves of variable stars