7 November 2007

I got an email today saying that only one of my observations of 17p?Holmes is going to be used at Recent News and Observations because the rest of the were not in the ballpark. That doesn’t surprise me since this is the first time I have ever tried this. I am told that it is partly my inexperience, that new people almost always underestimate the magnitude. They also said that the light pollution is hampering me which doesn’t make sense to me. If I am comparing the brightness of two objects I don’t think it should matter how much light-pollution the light is passing through as long as it is uniform over both objects.

Last night I added the average of all the reports other people have made (that have been used) to my chart. My magnitude assessments are real far off from what every one else has been reporting. My comet diameters, however, are close to the average and do follow the trend others have reported.

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STS-120, Discovery, landed a short while ago. I watched it on the net and listened to the press conference afterwards.

Having been able to have repaired the torn solar panel is a clear vindication of the need for sending humans into orbit – on some missions. I think a lot of what gets done in space can be done by robots, and that may mean the failure of some missions because there is no human to make a repair, but that is a risk that needs to be taken in some circumstances.

It was interesting to see the politics going on at the press conference. Michael Griffin, the NASA administrator talks the politics that Congress needs to hear to keep his agency funded. Once he makes a comment on something that had been thrown out to everyone all the others are mum. I thought there was one point where there might have been some disagreement between the administrator and one of the directors over shuttle tiles but the director assented to the administrator’s assessment when he was asked to, but it seemed to have been half-hearted.

One of the reporters asked about the retirement (and cannibalization) of Atlantis. They said that that is still supposed to happen after the Hubble Space Telescope servicing mission (11 day mission to launch no earlier than 7Aug08), but that they will continually reassess the situation until that time and it is still possible that Atlantis will be refurbished and remain in service since it would give them increased flexibility if something should happen to one of the two remaining shuttles.

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Astronomical Catalogs
Designator	Name	Objects
Upper case letter, 2 upper case letters or V and a number circle around dot		sariable stars
B ### dashed outline	Barnard	DSO: DrkNeb
C ###	Caldwell	DSOs
Ced ### green splotch	Cederbald	DSO: BrNeb
Cr ### yellow circle	Collinder	DSO: OCl
h ### dot with a line through it	John Herschel	double stars
IC ####	Index Catalogue	DSOs
LDN ### dashed outline	Lynds	DSO: DrkNeb
M ###	Charles Messier	DSOs
Mel ### yellow circle	Melotte	DSO: OCl
NGCM ####	New General Catalogue	DSOs
O*Sigma; dot with a line through it	Otto Struve	double stars
PK ### green dot over cross	Perek-Kohoutek	DSO: PlNeb
Sh2-### green splotch	Sharpless	DSO: BrNeb
Tr ### yellow circle	Trumpler	DSO: OCl
vdB ### green splotch	van den Bergh	DSO: BrNeb
β dot with a line through it	S.W. Burnham	double Stars
Δ dot with a line through it	James Dunlop	double stars
Σ dot with a line through it	Wilhelm Struve	double stars

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Here is a long term project for this coming year. R Cas (RA 23h53m00s) and V Cas (23h07m00s) are both long period variable stars that come to peak brightness during 2008. Since Cassiopea is nearly circumpolar we will have an opportunity to ovserve these stars dim and brighten. I don't know yet when V Cas was last at its brightness peak but it next peaks on 12Jul08. Its brightness range is Mag 12.2 - 7.9. R Cas is just coming off a brightness peak (30Oct07) and will dim then brighten to its peak on 21Dec08. Its brightness range is -12.6 - 7.0. Both of these objects will disappear for a time in SAR and then brighten and at their brightest I think that they should be visible in my binoculars.

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Observing Location	MO
Observational Period	2230-2330 EST
Atmospheric Conditions	Cloud Cover Clear Temperature 40°F; Wind Calm Humidity Moderate Feels Like Cold They have freeze warnings up for tonight. The sly is very clear, I saw 6 Pleiades and two stars in Orion’s Sword in the glare of the floodlights. Transparency Excellent Seeing I
Instruments	Golden Gate 7x35 binocular – Charlie SAR: Coulter CT-100 Newtonian reflector - Charlie Celestron Omni 20mm (21x) Celestron Omni 2x Barlow
Observing Party	Charlie Ridgway

Target 17P/Holmes Constellation Per Category Comet Time yyyymmdd.hhmm 20071107.2230 EST Comments The comet was easy to find tonight in both the 20mm eyepiece and with it Barlowed. I made my brightness assessment in the binocular first. I have changed my technique since I started using the binocular. The Recent News and Observations web page recommends three techniques for assessing a comet and says each one has advantages depending on the degree of compactness of the comet (DC) but doesn’t go into a lot of detail on what to do. In-Out Out-Out Way Out One thing I picked up on, for the Out-Out technique I guess was to get the comet and star out of focus until they both represent the same size disk in the eyepiece. I have found that the comet is so big that I can never get a star that big, but sometimes the stars disappear before I reach the end of the focus travel. So I have been using a modified Out-Out technique where I out focus until either the star disappears or I run out of travel on the focuser and then see which object looks brighter. I have done this the past three days and it seams easy and got me results that were more in line with those of others two days ago. Object Mag. Description β Tau 1.65 brighter &gamma Gem 1.93 Brighter β Per 2.10 Brighter γ Per 2.15 Brighter θ Aur 2.65 Brighter ζ Per 2.84 Brighter μ Gem 2.87 Brighter ε Per 2.90 Brighter γ Per 2.91 Brighter ζ Tau 2.98 Brighter δ Per 3.01 Brighter 17P/Holmes 3.01   ε Aur 3.03 Brighter ε Gem 3.06 Dimmer η Aur 3.18 Brighter ρ Per 3.32 Dimmer η Cas 3.46 Dimmer γ Tau 3.65 Dimmer ζ Aur 3.69 Dimmer ζ Cas 3.69 Dimmer δ Aur 3.72 Dimmer η Per 3.77 Dimmer ο Per 3.84 Brighter ε Cas 3.95 Dimmer Alpha Perseus Association   Dimmer Fishhook   Dimmer Hyades   Dimmer I am using my Pocket Star Atlas to identify what stars I am looking at and finding stars in it of a similar size dot to look at to refine the assessment but it does not show magnitudes like Planetarium so I am not swayed in my judgment by the numbers. I switched to the telescope to make my size estimation. Mag. FoV Count Dia. 21.6x 2.3° 5.5 0.42° 25.09’ 25’23’ 43.2x ~1° 2.6 0.38° 23.08’ 23’05” Average 0.40 24.00’ 24’00” There is a little bit bigger span between the low and high power assessments than I would like. It may be due in part to not knowing exactly what my FoV is with the Barlow installed.