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Observing >> Variable Star Observing and Radio Astronomy

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jgraham
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Reged: 12/02/04

Loc: Miami Valley Astronomical Soci...
CY Aqr – Dwarf Cepheid in Aquarius new
      #6187528 - 11/10/13 08:58 PM Attachment (21 downloads)

Telescope: Meade SN8, Orion Atlas EQ-G
Camera: Meade DSI Pro III, Johnson V filter
Guide scope: None (wind)
Exposure: 12x15sec, saved as FITS
Darks: Envisage Automatic
Flat: None
Software: Envisage, Nebulosity, Photoshop

Finally, after a series of equipment and weather problems I finally bagged CY Aqr. Despite the wind being too high an gusty to permit guiding, I managed to grab about 55 minutes of data before meridian flip, and another 2 hours after the meridian flip. What I didn’t realize is that the star was passing through maximum as it was transiting. As I was slewing around to the western sky I paused for a few minutes to grab a set of images of the moon. As the data shows, I missed a block of data as the star faded back to its minimum. However, I caught a second full period after the flip, so all is well.


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jgraham
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Reged: 12/02/04

Loc: Miami Valley Astronomical Soci...
Re: CY Aqr – Dwarf Cepheid in Aquarius new [Re: jgraham]
      #6187530 - 11/10/13 08:59 PM Attachment (19 downloads)

This is the time-order source data showing the data gap during the meridian flip.

This is the phase-order data showing that between the two data sets I got a pretty good profile for a complete period.


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jgraham
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Reged: 12/02/04

Loc: Miami Valley Astronomical Soci...
Re: CY Aqr – Dwarf Cepheid in Aquarius new [Re: jgraham]
      #6187531 - 11/10/13 08:59 PM Attachment (18 downloads)

The wind is calm this evening, so I’m taking another set of data that will cover both sides of the meridian. Having observed the maximum, I can now predict maxima with a fair degree of accuracy and I should get 2-3 complete periods this evening. This should be an interesting variable to observe visually as it has a nice set of reference stars nearby.

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Rich (RLTYS)Moderator
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Reged: 12/18/04

Loc: New York (Long Island)
Re: CY Aqr – Dwarf Cepheid in Aquarius new [Re: jgraham]
      #6188153 - 11/11/13 08:36 AM

Excellent observations, keep up the good work.

Rich (RLTYS)


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old_frankland
Carpal Tunnel


Reged: 03/28/05

Loc: San Francisco Bay Area
Re: CY Aqr – Dwarf Cepheid in Aquarius new [Re: Rich (RLTYS)]
      #6188518 - 11/11/13 12:32 PM

Time well spent; indeed! Excellent work.

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Astrodj
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Reged: 08/24/11

Loc: Missouri
Re: CY Aqr – Dwarf Cepheid in Aquarius new [Re: old_frankland]
      #6193772 - 11/13/13 11:48 PM

Thoroughly enjoyed the images and report. Very well done. Thanks.

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jgraham
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Reged: 12/02/04

Loc: Miami Valley Astronomical Soci...
Re: CY Aqr – Dwarf Cepheid in Aquarius new [Re: Astrodj]
      #6194010 - 11/14/13 06:37 AM

Thanks! I am very curious to see what this star looks like visually. I had an excellent imaging run a couple of nights ago with data from 3 complete periods. I'll post the updated period plot when I get back.

Neat stuff.


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NJScope
sage
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Reged: 03/08/04

Loc: NJ
Re: CY Aqr – Dwarf Cepheid in Aquarius new [Re: jgraham]
      #6196146 - 11/15/13 09:19 AM Attachment (18 downloads)

John:

Here's my contribution to the CY Aqr light curve taken earlier today (15Nov2013). I happened to be in the general neighborhood collecting data from 712 Boliviana and decided to give this SX Phe type fast pulsator a try. If you or anyone is interested, we can pool our data and perform a more detailed period analysis using Fourier transform or statistical (ANOVA) methodologies. All we would need to share is Julian dates (preferably heliocentric - HJD) and the corresponding magnitudes. Data from other time zones would be particularly helpful in eliminating aliases during period analysis. If anyone is interested in this collaboration, please PM me and we can work out the logistics of sharing data.

Edited by NJScope (11/16/13 10:31 AM)


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NJScope
sage
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Reged: 03/08/04

Loc: NJ
Re: CY Aqr – Dwarf Cepheid in Aquarius new [Re: NJScope]
      #6216896 - 11/26/13 10:41 AM Attachment (13 downloads)

Here's some additional CCD (V-band) light curve data for CY Aqr collected on Nov 21st and 25th. Fourier decomposition using PERIOD04 (freeware) reveals as expected a fundamental frequency at 16.3831893 cycles-per-day (0.061038176 d), however there also appears to be another harmonic series related to pulsation at 33.268464 c/d. This is different from other published studies on this system which deserves additional followup. Again, as mentioned in a previous posting, light curve data from additional sites can greatly help in eliminating aliases from single-site studies. As such, I would be very interested in sharing data with anyone who has recently collected photometric data on CY Aqr

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NJScope
sage
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Reged: 03/08/04

Loc: NJ
Re: CY Aqr – Dwarf Cepheid in Aquarius [Re: NJScope]
      #6226925 - 12/01/13 12:22 PM Attachment (11 downloads)

This is the latest photometric (V-band) run on CY Aqr. Fourier analysis of all data collected at UO is now sufficient to solidify the pulsation period (0.061038 d) of this SX Phe variable. The PERIOD04 model curve fit (red line) can be described by the primary frequency (16.3832 c/d) and its simple harmonics (1st-8th). No new behavior to report on this system compared to that already described in the literature for CY Aqr. All-in-all great target for an aspiring variable star aficionado looking to hone their photometry and data reduction skills.

Edited by NJScope (12/01/13 12:23 PM)


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