January 2016

HD32963—Host for a Jupiter-Sized Planet

Original article appears in GuideStar February, 2016.

by Bill Pellerin, GuideStar Editor

Finder chart

Object:  HD 32963 / SAO 76970 / HIP 23884
Class:  Star
Constallation:  Taurus
Magnitude:  7.6
R.A.:    5 h 7 m 55.7 s (2000 coordinates)
Dec:    26 deg 19 min 39.6 sec
Size/Spectral:  G5
Distance:  27.48 milli-arc sec, 119 l y
Optics needed: Small telescope

There’s an article in this GuideStar about the Frequency of Jupiter-Like Planets and the work Dominick Rowan is doing to establish how frequently these planets show up in extra-solar planetary systems.

Included in this study is a newly found Jupiter sized (.7 Jupiter) planet around star HD 32963. This is a 7.6 magnitude star in the constellation Taurus and it should not be a challenge to see. The finder chart to the right shows a circle of 1/4 of a degree (250 arc minutes) with a distinctive arc of three 11th magnitude stars just east of the subject star.

The star is just smaller than our Sun at .94 solar masses and the same color as our Sun. How would the Sun look if you were on a planet orbiting this star? It would look like this star!

If you’re wondering what they named this planet… it’s not very interesting. It’s HD 32683 b. It is known to have an orbital period of approximately 2372 days or about 6.5 Earth years.

The planet was discovered using the radial velocity method, a method that only works well on large planets orbiting close enough to the star to impart enough tug on the star that it moves. This movement is detected by a spectrograph as a (Doppler) shift in the color of the light received from the star.

As I’ve said several times in this area of the GuideStar, stars often have multiple designations as a result of being in multiple catalogs.

The HD (Henry Draper) catalog was published between 1918 and 1924 with spectral information for over 225,000 stars. The limiting magnitude on the catalog is about 9.

The SAO (Smithsonian Astronomical Observatory) catalog was published in 1966 and its purpose is to identify locations of stars on the sky (astrometry) accurately. It contains about 260,000 stars with a limiting magnitude of 9.

The most recent catalog, the Hipparcos (HIP) catalog was developed from data gathered by the European Space Agency’s Hipparcos satellite (1989—1993). This is high accuracy (in position) data, used, among other things to better determine the distance to stars using the parallax method. There are over 118,000 stars in this catalog.

President's Message

Original article appears in GuideStar February, 2016.

by Rene Gedaly

No conflicting meeting dates with holidays this year

Last year was truly one off. We had several schedule conflicts with holidays that many of our members observe. This year we find no such troubles. That is, unless you're a UH student. Friday night exams are scheduled for both Good Friday and Passover this year. As amateur astronomers, we're well aware of the vagaries of the lunar calendar on which many Judeo-Christian holidays are based; we just haven't met up with the attendant schedule conflicts lately. If you're a planner, all remaining meetings adhere to the 1st Friday schedule. Now, if we could just be assured of our meeting rooms.

Jessica Kingsley

Meetings held at UH in Bldg S&R1—unless they’re not

UH is busting at the seams and we are occasionally not assured of our 1st Friday night meeting location. As always, professors have first claim on rooms. Before leaving for the Friday meeting, check the website to see if there's been a room change. Not to worry if so. As we did in January, folks will be on hand to direct you to the new location.

Speaking of which, last year the board approved an ad hoc committee to investigate an alternate meeting venue, just in case. We won't spring this on you; in fact, hopefully a new location won't be necessary. Many commented on how nice the digs were at the UH Agnes Arnold Auditorium.

The 2016 leadership meeting

Pretty boring stuff. That unexpected comment took me aback and then made me smile. It was made at this year’s leadership retreat by an active member who decided to check out a board meeting but who evidently didn’t know what he was in for.

As for me, I was thrilled by the plans our talented committee chairs came up with this year. Still, I couldn’t help but sympathize with this member.

There’s a line from the movie Good Morning Vietnam in which a disheartened army clerk says “I live to collate.”

It does take a fair amount of administrivia to fund and run our programs. But they’re a lot of fun and make it all worthwhile.

Take two examples: Urban Observing at the George Bush Park and the new Novice Lab at the Dark Site in Columbus. Okay, a third, the Outreach events springing up all over greater Houston. There is a bit of tedious stuff that must get done by folks who’d rather be observing. Somehow, our leadership team finds the time and will to do it all.

Thank you.

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Rene

The HAS Dark Site—Part 3, What’s In Store for the Future

Original article appears in GuideStar January, 2016.

by Amelia Goldberg, Master Observer

We have seen so much growth in our club over the past several years, not only in membership but also out at our dark site. Our membership is the highest it has ever been with 600+ members. We have seen the huge success of the private observatory project. We see site use increasing with more and more members showing up on prime nights and many members out there during the week.

Most of us are aware of the plan to build more private observatories. But what else needs to be accomplished to make our dark site a state-of-the-art facility? What’s in the works for the coming year? What can we do to help make those plans a reality?

Actually, there is a lot that we can do. Club growth is a good thing but it does require our help, be it physical help or monetary help. Observatory Chairman, Mike Edstrom, has a vision of twelve additional RV sites on the west side of the property, a road to access them, water and power for them, and a parking lot to the north of the new private observatory field. That’s a tall order but all of it is really needed. As with the current RV sites, these new sites will pay for themselves in the long run. However, it takes cash now to get the infrastructure in place. The Board will not fund the entire project so donations from our members will really be needed to cover some of the cost.  Mike hopes to get all of this planned, funded and accomplished in 2016.

August 2015 Star Party

Another item in Mike’s vision is a new bunkhouse for women and families. It’s needed and it’s fair to our growing number of women and women with young families who want to observe. Unlike the RV sites and private observatories, the bunkhouse will not pay for itself since no rent is charged for its use. If we build it ourselves, we can probably do it for about $4k in materials. We’d really like to get the female membership involved in the construction of the bunkhouse. I know that Rene and I are not the only gals who know how to use a hammer, saw or paint brush. Let’s show the guys what we can do.

The f/7 telescope in the observatory building needs a new mount with GOTO capability. The Board has approved money to have this done. We have purchased and installed new dual speed focusers for both the f/7 and f/5 telescopes using money from this year’s budget.

All donations to the building and upkeep of the dark site are greatly appreciated. All of your personal time and effort, helping in any way you can, is valued by the club. There are so many ways to help, even if it’s just donating some of your time. We can all be part of what’s happening at the dark site. We can all be proud that we helped to make it what it is.

President's Message

Original article appears in GuideStar January, 2016.

by Rene Gedaly, President

How many women members would you imagine we have? Take a guess. Fifty? One hundred? As of this writing there are 167 members who are women or girls. I bet some of you can remember when the entire membership hovered around that number. Ninety-five of those 167 are associate members. Looking over the list, we have some very active and supportive associates. Thank you all so much.

For many women membership is primary

That leaves 72. Seventy-two of us are non-associate female members: regular, student, and sustaining. We're at the novice and membership meetings, at the dark-sky site for prime- and novice nights, we’re active contributors on the HAS Facebook group, we give talks, participate in outreach, and take leadership positions. A lot of us are armchair amateurs. By choice? Or waiting in the wings?

HAS Women Members

 The time crunch

The web is a wonderful thing. Formulate a good search and all manner of reliable information pops up. I came across an interesting paper entitled Involving More Women in Amateur Astronomy by Mary Lou Whitehorne. “There are two primary reasons there are fewer women than men in amateur astronomy,” she says: “sociological and biological."

The paper was delivered at the Amateur-Professional Partnership in Astronomy conference held in 2000 so it's a little dated. For example, there are increasing numbers of women involved in amateur astronomy, at least at HAS. But the sociological reason for continued participation is still relevant: "Amateur astronomy is a hobby and comes after family and career commitments." The same can be said for men, of course. We all struggle to find that balance between work and family and treasured avocation.

Biology is destiny?

As for the biological reason, Whitehorne mentions the lack of bathroom facilities. Happily that's not a problem for us. We even have a bunkhouse. But speaking of that bunkhouse—so beautifully remodeled by Ana and Don Taylor and crew—I know from personal experience that if a woman takes one of the beds, the men will not enter. Makes sense. But when I rejoined HAS in 2009, I was determined to make use of the dark-sky site this time around. However, I soon realized I was left with the option of, in effect, kicking the men out of the bunkhouse and sometimes the chartroom, or camping in my car. I've done all three and in no option did I feel entirely comfortable.

A trade-off

One of the most difficult decisions I’ve ever made, no exaggeration, was to forgo the purchase of a fully outfitted 15" Ultra Compact Obsession telescope so that I could get myself a little travel trailer to park at the dark site. Now I have a place to sleep after a good night’s observing without taking more space than my fair share. I’m still lusting after that Obsession though.

That was my trade-off. What trade-offs, I wonder, are the other women members having to make?

A solution

Amelia Goldberg finishes her three part series covering the dark site in this issue of the GuideStar. It’s written from the perspective of a long-time member, a master observer… and a woman. I won’t steal her thunder, but take a look at her article. She reports on a possible solution to both the sociological and biological problems of would-be women observers—thanks to some forward-thinking, fair-minded men and women.

Note: I'd like to thank Amelia Goldberg for agreeing to take on the three part series about our Dark Site. Beautiful job. Our Observatory Director Mike Edstrom and committee have been transforming the dark site and observatory, and consequently our astronomy club. Thank you, Mike and crew. And members, if you haven't made it to the dark site recently, you ain't seen nothing yet.

Shallow Sky Object of the Month: Beta (β) Aur—An Eclipsing Binary

Original article appears in GuideStar January, 2016.

 Beta Auriga, an eclipsing binary

by Bill Pellerin, GuideStar editor

Object:  β Aur
Class:  Eclipsing Binary Star
Constellation:  Auriga
Magnitude:  1.89 to 1.98
Period: 3.96 days
R.A.:    5 h 59 m 32 s (2000 coordinates)
Dec:    44 deg 56 min 51 sec
Size/Spectral:  A2, 9100 degrees K
Distance:   82.1 ly
Optics needed: Unaided eye or small telescope

The schemes for naming stars can be confusing. The Bayer designation consists of the letters of the Greek alphabet (normally in order of brightness) and the genitive (possessive) name of the constellation. The designation β Aur is typical of a Bayer designation.

Variable stars typically have a letter R, S, T, U and so on, and then the genitive name of the constellation, such as R Aur. R Aur turns out to be an unrelated Mira variable that changes from about 7th magnitude to about 14th magnitude.

That said,  β Aur is an eclipsing variable that only drops about .1 magnitude (at the limit of being able to detect visually) every 3.96 days. Given the color of the two stars that comprise this double you’d be correct to assume that these are large stars, and given the period of the orbit you know that they’re very close to each other.

What else can you know from these simple observations? Well, it’s clear that we earthlings are not on a direct line to the orbital plane of these two stars. If we were, the dip in magnitude during an eclipse would be larger than we observe it to be. So, we’re only seeing a partial eclipse of the two stars.

The most famous eclipsing variable star is Algol, the demon star, described in the November, 2006 GuideStar. Algol is so well known that Sky & Telescope magazine publishes a list of the predicted minima of Algol every month.

If you investigate variable stars you’ll find they fall into many categories but the first fork in the road is whether the star is an eclipsing binary or an intrinsically variable (pulsating, usually) star. Eclipsing binary stars represent the first fork in the classification of variables and the easiest to understand. Intrinsically variable stars fall into many categories, identified (usually) by the ‘prototype’ star (one that well represents that category).

By mid January, this star crosses the meridian (i.e. transits) at 22:00 (10:00 p.m.), so it’s very conveniently placed for viewing. Look due north.

That’s not the whole story. There’s a 14th magnitude companion to the pair that lies about 13 arc seconds away. It’d take a larger telescope and dark skies to see this one, though it may be hidden by the brightness of the two primary stars.

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