J/AJ/162/189 125 years light curve of HS Hydrae with DASCH (Davenport+, 2021)
The Rise and Fall of the Eclipsing Binary HS Hydrae.
Davenport J.R.A., Windemuth D., Warmbein K., Howard E.L., Klein C., Birky J.
<Astron. J., 162, 189 (2021)>
=2021AJ....162..189D 2021AJ....162..189D
ADC_Keywords: Stars, double and multiple; Binaries, eclipsing; Photometry, CCD
Keywords: Binary stars ; Eclipsing binary stars
Abstract:
HS Hydrae is a short period eclipsing binary (Porb=1.57day) that
belongs to a rare group of systems observed to have rapidly changing
inclinations. This evolution is due to a third star on an intermediate
orbit, and results in significant differences in eclipse depths and
timings year to year. Zasche & Paschke revealed that HS Hydrae's
eclipses were rapidly fading from view, predicting they would cease
around 2022. Using 25 days of photometric data from Sector 009 of the
Transiting Exoplanet Survey Satellite (TESS), we find that the primary
eclipses for HS Hydrae were only 0.00173±0.00007mag in depth in
March 2019. This data from TESS likely represents the last eclipses
detected from HS Hydrae. We also searched the Digitization of the
Harvard Astronomical Plate Collection archive for historic data from
the system. With a total baseline of over 125yr, this unique
combination of data sets-from photographic plates to precision
space-based photometry-allows us to trace the emergence and decay of
eclipses from HS Hydrae, and further constrain its evolution. Recent
TESS observations from Sector 035 confirm that eclipses have ceased
for HS Hya, and we estimate they will begin again in 2195.
Description:
The Digital Access to a Sky Century at Harvard (DASCH) is an effort to
create a uniform digital catalog of photometric measurements from
astro-photographic plates taken between 1885 and 1992. Each plate is
digitized by back-illuminating it and scanning using a CCD camera.
That image is then calibrated based on the plate's sensitivity, and
Point-Spread Function (PSF) photometry is computed for each source in
the image.
Objects:
-----------------------------------------------------------
RA (2000) DE Designation(s) (Period)
-----------------------------------------------------------
10 24 36.77 -19 05 33.0 HS Hydrae = V* HS Hya (P=1.57d)
-----------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
fig2.dat 36 1390 Phase-folded historical light curves from DASCH
fig4.dat 50 14 Eclipse depths and derived inclination as a function
of time for HS Hydrae
--------------------------------------------------------------------------------
See also:
II/264 : ASAS Variable Stars in Southern hemisphere (Pojmanski+, 2002-2005)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/MNRAS/455/4136 : Kepler triples (Borkovits+, 2016)
J/A+A/609/A46 : Light curves 0f 6 MC eclipsing binaries (Jurysek+, 2018)
http://projects.iq.harvard.edu/dasch : DASCH project page
Byte-by-byte Description of file: fig2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 F14.6 d JD [2412585/2447708] Julian Date
16- 26 F11.6 yr Obs.Y [1893/1990] Year of the observation
28- 31 F4.2 mag Dmag [7.2/9.67] Apparent DASCH photgraphic plate magnitude
33- 36 F4.2 mag e_Dmag [0.07/0.3] Uncertainty in Dmag
--------------------------------------------------------------------------------
Byte-by-byte Description of file: fig4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 F11.3 d JD [2416831/2458556]? Julian Date
13- 23 F11.6 yr Obs.Y [1904/2020] Year of the observation
25- 31 F7.5 mag Depth [0.001/0.65] Eclipse depth
33- 39 F7.5 mag e_Depth [0.00007/0.2] Uncertainty in Depth
41- 45 F5.2 deg i [71.8/88.9] Inclination
47- 50 F4.2 deg e_i [0.02/8]? Uncertainty in i
--------------------------------------------------------------------------------
History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 21-Dec-2021