12 replies to this topic

[Centaur]

The elusive little planet Mercury has begun its apparition as a morning star following its inferior conjunction between Earth and Sun on 2010 SEP 03. The morning celestial geometry is favorable at this time of year for observers north of the tropics, while poor for those located south of the tropics.

I’ve created diagrams illustrating Mercury’s entire current morning apparition as observed from Chicagoland and Sydney. However, they should well serve most observers in the respective hemispheres. They can be seen by clicking: http://www.curtrenz.com/astronomical then going to the page for the Inferior Planets.

All dates given here are based on CDT (UT-5). Mercury will reach its greatest western elongation of 17.9° from the Sun on SEP 19. It will attain its greatest altitude at 30 minutes before sunrise from Chicagoland on SEP 20 at 10.8°. On that same date it will achieve dichotomy (50% illuminated like a Half Moon). Before that date it will be a crescent and afterward gibbous. While increasing in brightness, it will then fall to superior conjunction behind the Sun on OCT 16.

Mercury will pass 5.6° south of Regulus on SEP 13. During this apparition there will be no other conjunctions by Mercury near first magnitude stars, planets or the Moon while away from the glare of the Sun.

Photos and descriptions of Mercury’s morning apparition would be welcome additions to this thread.

[E_Look]

Thank you!

Though, ooiiyyy, morning star! It's the one planet I haven't caught yet (seeing stars by today's standing eight count). Maybe when it comes by in the early evening...

[Centaur]

Thank you!

Though, ooiiyyy, morning star! It's the one planet I haven't caught yet (seeing stars by today's standing eight count). Maybe when it comes by in the early evening...

You’re welcome, Ed. I’m not an early bird either. There will be an evening apparition during the late fall, but it will be a difficult one for observers north of the tropics. A much better one will present itself during early spring.

[E_Look]

I'll be waiting!

[Rick Woods]

I tried for it this morning, but got clouded out.
Morning apparitions are the best for surface observations, since it just gets better as the morning progresses.

[Centaur]

I tried for it this morning, but got clouded out.
Morning apparitions are the best for surface observations, since it just gets better as the morning progresses.

I'm looking forward to your drawings and descriptions, Rick.

[Rick Woods]

It's been a bust so far, Curt. I've gotten two so-so sketches, not nearly as good as I got last time I tried this. Not worth the loss of sleep to get up so early.
The problem is that Mercury is still so low when the sun gets high enough to hit my scope and ruin the thermal equilibrium. This is Arizona, and it gets hot really fast. I think that from a horizon point of view, Mercury is only about 8 degrees ahead of the sun.
I have no scanner at this time, so I can't post my sketches; but they're no great shakes anyway. Not nearly the detail I saw two years ago.

My next try will be in the evening apparition in Nov-Dec. Maybe I can begin observations when it's high in the sky, well before sunset.

[CarlosEH]

Curt,

Thank you for the graphics on Mercury as a morning star. I hope that we all get a good view of it.

Rick- I am starting to think that Giovanni Schiaparelli had the right idea about Mercury- Observe it in the daytime sky. Obviously an observer has to be very careful NOT TO POINT THEIR TELESCOPE ANYWHERE NEAR THE SUN, but such observations tend to be more fruitful than hoping for a glimpse of detail near the horizon. I have attached my daytime observation of Mercury from last year (August 22). I would publish your observations anyway.

Happy Mercury Observing!

Carlos

Attached Thumbnails

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[Centaur]

That’s a fine drawing, Carlos. Thank you for sharing.

[Rick Woods]

Here's a quote from Schiaparelli on observing Mercury:

"... I have had the the telescope directed upon Mercury several hundreds of times, usually to little purpose, and with the loss of much time."

Boy, is that true. And it's something to keep in mind when you try observing it: if it's really bad and you can't see anything, you're in very good company. Try again later.

(The quote is from "The Conquest of Space" by Ley and Bonestell).

[Centaur]

"Tis a lesson you should heed, try, try again. If at first you don't succeed, try, try again." Thomas H. Palmer

[Rick Woods]

Absolutely!

[CarlosEH]

Curt,

Thank you for the compliment on my Mercury observation. It was fun and exciting to see this elusive planet in the daytime sky, especially to detect any detail.

I agree with the quotes and that is PERSISTENCE! PERSISTENCE! PERSISTENCE! Just ask the "Little Engine That Could."

Carlos