C/2022 E3 (ZTF) (08 Jan 2023)

 Comet, Solar System  No Responses »
Jan 082023
 

Due to prompting from some of my west coast friends, I stayed up way too long and got these images of the “green comet” just before encroaching clouds and pending dawn stopped the session. Additional interference was light from a 16-day old Moon. But this stack shows the comet is developing a nice tail.

C/2022 E3 (ZTF)
[CV:2x60s]

The comet is a long period comet. JPL says the orbital period is not defined; other sources just say the orbit is greater than 50,000 yrs. It spends most of that orbit below the ecliptic, but right now is above it and just outside Earth’s orbit. It will cross below the ecliptic around the 12th of February roughly halfway between the Earth and Mars. It will be closest to the Earth on the 1st of February.

C/2022 E3’s orbit.
(Graphic courtesy of the JPL Small-Body Database Browser)

So, this is just a preview. In a couple of weeks, the comet will be above the tree line at a more convenient time (0300), the Moon will not be up, and I will be able to take the necessary exposures to put together a color photo.

 Posted by at 12:51

Comet 29P/Schwassmann–Wachmann (28 Nov 2022)

 Comet, General Commentary, Solar System  No Responses »
Dec 022022
 

Comet 29P is known for its periodic outbursts. It grabbed earth-based astronomer’s attention again on the 22nd of November. On average, the comet brightens 7.3 times per year. Normally, the comet’s magnitude is around 16.0 but current measurements show the comet at 12.2. Remember, the lower the number, the brighter the object. This image shows the characteristic ‘notch’ in the comet’s coma and close examination shows a slight, barely visible twist in it.

Comet 29P (Schwassmann–Wachmann 1) [C:1x60s]

Because its orbit lies entirely between Jupiter and Saturn, it is classified as a Centaur object. Its year is 14.7 earth years long and currently lies above the ecliptic. The nucleus of the comet is estimated to be roughly 60 km (37 mi) in diameter.

29P’s orbit.
(Graphic courtesy of the JPL Small-Body Database Browser)

As of the 2nd of December, the comet is visible in the constellation Gemini. It rises around 1830, transits the meridian at 0155 and sets well after sunrise at 0914.

Cosmic ray/Muon track

Also visible top-center in the first image is an excellent example of how sensitive modern CCD chips are.
The tracks visible are attributed high energy particles impacting the chip. Straight tracks are expected from cosmic rays or muons created by cosmic rays hitting atoms in our atmosphere. Curved tracks, known as worms, indicate somewhat less energetic particles thought to be generated by “Compton scattering” due to emissions by physical components in the immediate area of the chip. Some glass formulae (e.g. BK7) are notorious for this. However, the proximity, directionality and time constraints of this image could indicate that the straight and curved tracks are related to the same event.

 Posted by at 13:34

C/2019 L3 (ATLAS)

 Comet, Solar System  1 Response »
Dec 242021
 

Unfortunately, Comet Leonard is not visible from the PTO due to the surrounding tree line. Luckily, there is always more than one comet in the sky. FYI, as of today (24 Dec 2021) there are more than 900 objects in the MPC list of observable comets.

This is comet C/2019 L3. It was discovered on the 9th of June 2019 by the ATLAS program.

C/2019 L3 (ATLAS)
[C:60x60s]

The comet is currently visible in the constellation Gemini heading towards perihelion on the 9th of January 2022. Right now, it is above the ecliptic but due to cross into the southern sky on the 18th of February next year.

C/2019 L3’s orbit viewed from above the solar system.
Graphic courtesy of the JPL Small-Body Database Browser.

As can be seen in the orbit diagram, the comet’s perihelion of 3.5 AU puts the closest it comes to the Sun well outside the orbit of Mars.

 Posted by at 18:03

67P/Churyumov–Gerasimenko

 Comet, Solar System  No Responses »
Sep 082021
 

67P/Churyumov–Gerasimenko is a short period comet completing its orbit around the Sun every 6.45 years. Right now it is heading back into the inner solar system towards a perihelion on the 2nd of November. It is still below the ecliptic and has just crossed the orbit of Mars. Currently, it is visible in the constellation of Taurus.

This animation is a 31 image set of 60 second exposures.

67P’s orbit viewed from above the solar system.
Graphic courtesy of the JPL Small-Body Database Browser.

67P is one of the most intensely studied comets of all time. Sitting on the surface of 67P is the now inert Rosetta spacecraft along with its Philae lander. Rosetta rendezvoused with the comet in 2014 and orbited the comet throughout its 2015 perihelion. At the end of its mission the spacecraft was soft dropped onto the comet. The Rosetta mission ended on 29 September 2016 when the spacecraft impacted the comet at an estimated speed of 2 mph.

 Posted by at 11:07

Comet C/2020 R4 (ATLAS)

 Comet, Solar System  No Responses »
Apr 282021
 

UPDATE: I was able to image the comet on the morning of the 29th and shot enough imagery to assemble a short animation showing its motion. The animation is sixty 60 second images.

 

Comet C/2020 R4 (ATLAS) spends only a brief time above the ecliptic during its 956 year orbit of the Sun and for now it is. This image captures it on the 21st of April after it passed perihelion and is heading back out into the far solar system. The comet was located in the constellation Hercules when the image was taken, but is moving quite rapidly and as of today (the 28th) is in Boötes. If you look closely, you can see the comet’s shape is elongated due to its motion even though it is only one 60 second exposure. The comet is crossing the FOV from upper left to lower right.

The comet was discovered by the Mauna Loa telescope of ATLAS on the 12th of September last year.

ATLAS stands for Asteroid Terrestrial-impact Last Alert System. The system consists of two 0.5m telescopes; one at the Haleakala Observatory on the island of Maui in Hawai’i and the other at the Mauna Loa Observatory on the big island of Hawai’i.

Comet C/2020 R4 (ATLAS)[CV:1x60s]

The diagrams below show its orbit in full and much closer to the Sun to illustrate its location in relation to the Earth at the time of the photo.

C/2020 R4’s orbit in an high overhead view of the solar system.
Graphic courtesy of the JPL Small-Body Database Browser.

C/2020 R4’s orbit in an oblique view of the solar system.
Graphic courtesy of the JPL Small-Body Database Browser.
 Posted by at 14:08
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