Mini Observing project - Neglected John Herschel Doubles (HJ5489)

[lunator]

I have been continuing to investigate some more John Herschel doubles.

Most of the pairs are relatively easy to find and measure but one pair HJ5489 has proved elusive.

The primary is 6 mag star HD130917. The seconday is 110" away the North East. The magnitude for this star is noted as 10.6 but when I observed it it was fainter than magnitude 12.5 (comparing to stars noted in the FoV and checked against Tycho).

I have check the Aladin database and most of the photometric plates say the 12.5-13.0 Mag is consistent.

I am using an 8" scope under moderately LP skies. I would be interested if anyone is able to see the star and if so what they rate it's magnitude to be.

The useful information would be what you skies limiting naked eye magnitude was, what size scope you have and if you could see the star (with Averted or Direct vision) or not.

Any response will be included in my submission to the Webb Soc and will help improve the accuracy of the WDS.

Cheers

Ian

[OXO]

Consider it done Ian interesting project !

James

[Astroman]

Do you have a position, or will you force me to look it up?

[lunator]

Do you have a position, or will you force me to look it up?

6th Mag star just North East of IZAR can't miss it.......

Here is the info

Double Star

HJ 5489

Magnitude: 5.80/10.60

1878:112.6"/ 23°

1959:111.2"/ 22°

Spectral Class: A4V

Note: p

DM:+29 2581

J2000 RA: 14h49m58.40s DE:+28°36'57.0"

Date RA: 14h50m15.02s DE:+28°35'21.9"

Azimuth :+129°15'

Altitude :+59°51'

Rise : 13h47m Azimuth:+38°39'

Culmination : 22h46m

Set : 7h45m Azimuth:+321°21'

[Astroman]

Thanks. I'll give it a look tonight.

[lunator]

James, AM

Did you manage to observe this?

Cheers

Ian

[OXO]

Hi Ian,

Sad as it sounds not yet not had the clear skies to do it :shock: was planning to and take an image too..

James

[lunator]

James

Sorry to hear that. Hope the skies clear soon.

[Astroman]

James, AM

Did you manage to observe this?

Cheers

Ian

I took a look at it the next night, but the seeing was so bad I couldn't split it. (I was hoping you'd forget...) I'll try it agin after the Moon goes down this weekend, if you like. I'll be up anyway at ~2am Monday night for an occultation.

[lunator]

Thanks AM

I would be very interested to know what you thought it's magnitude is.

Rgds

Ian

[Kaptain Klevtsov]

I'll be up anyway at ~2am Monday night for an occultation.

I don't get the euphemism, but it sounds good to me!

Captain Chaos (willing to have a bash at an occultation)

[Astroman]

It's not a euphemism, it's a hippopotamus.

Anyway, I dabble in asteroid occultations of stars. When an asteroid passes in front of the star, it dims the star, or blocks it completely. With many people doing this simultaneously, from known locations, it's possible to triangulate the date, which accomplishes a couple things. First, it can show an outline of the object. Each observer contributes a "cord", or line that represents how long the star was occulted. Put the cords together, and you get a profile of the shape of the object. Second, you can calculate the orbit of the object better with more cords. They'll indicate the direction of the object with great accuracy, allowing us to fill in some blanks as far as orbital elements and if the object had changed course since a previous observation. It's a lot of fun, watching the star disappear and reappear in your EP!

Here's a link to this particular occultation. You can go back to higher directories on the site for others and results, too.

http://www.asteroidoccultation.com/2006_07/0704_144_7859.htm

[Kaptain Klevtsov]

The procedure is very interesting. Sounds like you gather the length of the asteroid using the occultation method measuring (in UK english) chords, then when you have a big enough pile of those you stick them together to make the 3D image.

I bet you could make a 3D model of a swan by looking at the sun all day for years on end using the same technique, now where do I get funding for that?

Captain Chaos

[OXO]

Hi Ian,

The primary is 6 mag star HD130917. The seconday is 110" away the North East. The magnitude for this star is noted as 10.6 but when I observed it it was fainter than magnitude 12.5 (comparing to stars noted in the FoV and checked against Tycho).

I would say it is more like Mag 11 personally this was using a 10" Reflector f/5 and a ED80 Frac, sorry its taken so long but as you know our skies are pants...

Cheers

James

[Astroman]

Monsoons have hit here in AZ. Doesn't look like I'll be able to check it out. Sorry. This is generally the time of year I shut down and do maintenance. Observing can be an excercise in futility-clear during the day and evening, thunderstorms and dust storms rolling through at nightfall.

[lunator]

Thanks James & AM

James looks like this could be a variable?

As I have had several reports confirming a Mag 13 star and several brighter.

Could you draw a sketch of the field with comparison stars?

I would like to send it to Bob Argyle for submission to the Webb Soc?

Cheers

Ian

[OXO]

Hi Ian,

James looks like this could be a variable?

It look's that way to me Ian i will however take another look this evening and also draw a Sketch/image the Fov for you

Regards

James

[lunator]

James

Thats great.

I look forward too seeing the sketch

Cheers

Ian