Variable Stars [with digital cameras]

Mira Observations

Richard DeCoster is our variable star expert.  He has spent years observing and recording the changing light of Mira (Omicron Ceti).  Below are the journals he submitted to the ARCS project as well as his recommendations for observations.  Please see bottom of page for numerous Subpages.

Resource Links -  AAVSO American Association of Variable Star Observers


[NOTE: UPDATE November 07, 2011:  Mira is currently in the evening sky, just below Jupiter; so you can't miss it.  In September, 2011 Mira reached one of its maximum maxima ever!  [See below.] It is now of course fading, but still worth a look.  Watch it disappear, then use binoculars.  Then use SkyNet.]


Mira and Jupiter from Yerkes Observatory: 9-30-2011

Large area of the sky from Evanston, looking north-northwest about 6:30 pm on Feb. 16, 2008, just before the clouds arrived.

Toward the bottom right: The Constellaiton Cepheus with two notable variable stars circled, Delta Cep and Mu cep.

A number of constellations: Cepheus, Lacerta and Cassiopeia and portions thereof: Draco, Ursa Minor, Camelopardalis and Andromeda.

Journal Observations November 30, 2007

Physics colleagues- Mira is starting to get within binocular range so I’m trying to initiate my viewing project for next semester. Since we do decibels in Physics 21 and 22 and the inverse square law I’m using this as an “authentic” application of log type compression schemes [stellar magnitudes rather than decibels] and the inverse-square law in its“distance-modulus” format. I’ve attached a picture I took Friday night 11-30 of the region of the sky in Cetus, pretty much low and straight south at 8 pm or so. Mira not yet visible to me. The original shows better than this “paint-edited” version but it gives the idea. I’ve inserted some standard comparison stars. Mira should get at least as bright as m = 4 or better, so would compare with m = 3.6 gamma ceti or m = 4.1 delta ceti [which I inadvertently covered] and last time around got up to m = 2.5 or so alpha ceti [off the picture]. So over the next several months Mira will rise above the stars in this picture and be easily visible in the camera and binoculars. If I can get pictures with our DSI in *.fts format, which so far I have not as it is always cloudy by the time I get things set up, then we can do intensities with the HOU or Subaru software.  I am also working with Vivian at getting pictures with Y24 so can get the faint stuff-Mira may be too bright eventually for Y24? Right now it's at 8.2 to so, a bit fainter than it should be at this point in its cycle.

Fig. 1: Mira should be where the empty oval is located. It is not yet bright enough to be seen here on Nov. 30, 2007. See the picture below taken on Dec. 12, 2007 [I think] when Mira has appeared at m = 7.1 or so by comparison with the 7.1 and two 7.3 stars in this edited image.

 Observation of Mira Wednesday Dec. 12, 2007

Although it became cloudy about 6:15 pm I was able to race the clouds and got home in time to actually get a picture of Mira at m = 7.2 or so before the clouds won. I am now trying to download one of the pictures.

Mira in Evanston's light-polluted skies. My first observation since Mira disappeared into the sunlight last March!

Fig. 2: Mira-the Wonder Star-reappears. Mira is about 1/3 from top and 1/4 from right edge of picture. Compare with star field from the image from earlier in the month when Mira was not to be seen.

Mira picture. I will edit this once I get the picture actually downloaded. At 4 pm on Sunday Dec. 16 it is still clear. I hope to get additional pictures tonight. I also hope to edit this picture with Paint to point out where Mira and comparison stars are.

Note-These pictures do not show Mira very well on my monitor at work. I will work to enhance the image.

Mira Observations Sunday December 16

Another race with the clouds. First set of pictures taken 5:15 to 5:30 pm. Menkar seemed so bright low is SE sky that I first took it for Aldebaren. Second set of pictures taken about 6:15 by which time Menkar seemed much fainter as it had moved more to the south from me and more into the bright Chicago sky. Also got pictures of T Ceti. Moon at 1st quarter and new snow cover made for very bright sky background. Evan with 7 X 50 binoculars I could see only abut m 5.4 star. I could not see Mira-only with the camera.

Mira- Two views- Dec. 16, 2007

Two pictures taken in moonlight [1st quarter] with fresh snow cover. Mira about m = 6.5 or so. It is "reddish" in the pictures compared to the "blueish" stars.

Fig. 3: Mira Dec. 16, 2007- 6:15 PM CST-Evanton, IL

Fig. 4a: Mira-5:29 PM low in Southeast 12-16-07 snow cover and 1st quarter moon.

Fig. 4b: Enhanced image-Mira-5:29 PM low in Southeast 12-16-07 snow cover and 1st quarter moon.

Fig. 4c: Mira-the Wonder Star: December 16, 2007

Mira Observations of Monday 12-17-2007

Clear night with moon about first quarter and snow covering th egorund. Mira was easy to find and I took about a dozen pictures.

Mira 12-17-07. Brightening rapidly.

Fig. 5a: Mira continues its rapid brightening.

Fig. 5b: Mira zoomed in abit from 5a, and shorter exposure.

Mira-edited pix to enhance contrast. Taken 12-17. Lots of moonlight and snow cover.

Mira Dec. 17, 2007 edited with PhotoEditor.

 Mira-Dec. 18, 2007

 Mira in Cetus Dec. 18, 2007 about 6 pm. Moon closer to Cetus and beyond 1st Quarter. 

Mira towards upper right. Gamma Ceti upper left. Delta ceti diagonally down and right. Mira is second star to far right of delta.

Mira upper right about 6 pm on 12-18-2007

Mira-edited pix to enhance contrast. Mira 12-18. More moon and snow cover. Could still not see with 7 X 50 binoculars.

Mira 12-18-07 about 6 pm. Photo Editor enhanced.

Mira Dec. 25, 2007

Mira [right]with Alpha, gamma and delta Cephei; and alpha piscius upper right.

Magnitudes of nearby stars [delta ceti for example] from AAVSO A chart. Mira continues to rapidly brighten.

Mira 5:19 pm cst 12-25-2007 from Evanston, IL into Chicago's smaze.

Mira Jan. 3, 2008

Mira with gamma and delta ceti on Jan. 3, 2008

Mira with alpha, gamma and delta ceti Jan. 3, 2008

Jan 27th Update-Mira maxed out?

Mira has apparently reached maximum, about 2 magntiudes below its apparition of 11 months ago.

Clouds persist over Evanston. I may have a few pictures to place here but not many. Mira has also moved further west in my southern sky so it is behind a tree and not easy to image. I will work on this as Mira goes thru its dimming phase and see how far I can follow it down. I also hope skies clear and I can get up to Yerkes to image it there.

I have tried to follow the more unpredictable variable T ceti as well but it has moved behind a tree. I still need to get active with our Meade DSI to take pictures that can be analyzed.

Mira with alpha, gamma and delta cep on Jan. 28, 2008

Mira 1-28-08 just after max?

A clear night but no photo. Sunday Feb. 10

Finally a clear day, but the temperature never made it above 0 F. I went out to look at the space station at 6:41 pm and it did its thing. Mira was toward the south southwest and had dimmed a bit to fainter than 4.1 comp star delta cet. Also looked at delta cep and it was at its fainter extreme. Mars shining brightly seemed to be moving away from beta Taurus? In any event it was too cold to try to take a picture.

Clear, with lots of moon Feb. 13, 2008.   Mira on Feb. 13, 2008. AAVSO shows Mira got only to about m 4.0 or so and is now starting to decline. It seemed to my eye in our lousy sky to be a bit dimmer than delta cep at m = 4.1 as I recall.

The moon was nearby, but it started out clear. By 6:30 I got a few pictures, after watching the ISS fly by starting 6:08 pm. But by 6:45 it was quite cloudy again. Pictures of Mars and delta cep were not obtained.

Mira in moonlit sky, early evening.   Mira still around m = 4.1 to the southwest from Evanston about 6:30 pm or so.

Delta Cep-Feb. 16

Delta Cep with epsilon and zeta, plus mu cep, the largest naked-eye star and an Orion type variable as well.  

Delta cep-used in my physics class to illustrate use of Inverse Square law I = L/(4*pi*R^2).

Mars coming into Auriga, along with our friends, the clouds.

Orion as clouds once again flow in. This was typical of observing tries this winter.

Orion to southest of Evanstons, Mira is eclipsed, and viewing is soon ended. Typical weather pattern for the fall.