03/19/2023 – Ephemeris Extra – Zodiacal light

This is the time of year when the faint glow can be seen in the west at the end of asttronomical twilight in the evening. It’s called zodiacal light. It is difficult to spot the first time. The final twilight glow tends to be horizontal, along the horizon, while źodiacal light has a thin pyramidal shape tilted to the left along the constellations of the zodiac. Right now, Venus appears in the heart of the glow.

Some of my older blog posts also cover zodiacal light with images of it I’ve taken, so search for zodiacal light in the spot provided.

On a personal note: I’m expected to be discharged from rehab by month’s end. I’m hoping that a couple of weeks after that, I can get back to a regular schedule. Here’s hoping.

Bob

03/29/2022 – Ephemeris – Finding zodiacal light

This is Ephemeris for Tuesday, March 29th. Today the Sun will be up for 12 hours and 37 minutes, setting at 8:06, and it will rise tomorrow at 7:27. The Moon, 3 days before new, will rise at 7:10 tomorrow morning.

The evening sky will stay dark for the rest of the week, so it’s time to look for the zodiacal light in the evening. It is a faint but towering glow that can be seen after the end of astronomical twilight on moonless nights. It is seen in the west in the evening in late winter and early spring. The axis of the glow is the ecliptic, the apparent annual path of the Sun in the sky, along which lie the constellations of the zodiac. It’s a glow whose wide base is in the west that extends upwards and to the left. Right now, the end of astronomical twilight is about 9:49 p.m. and advancing at a rate of a minute or two each night. Go to a spot with a dark western sky, no big cities or towns out that way. Zodiacal light is caused by dust spread out around the Sun.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hours). They may be different for your location.

Addendum

The western sky at 10:22 pm, March 25, 2019. Mars appears below the Pleiades in zodiacal light. Credit, mine – Canon EOS Rebel T5, 18mm f.l., f/3.5, 8 sec. ISO 12,800.

I’ve added the approximate ecliptic line from an image I took from a year earlier.

My article in April’s Stellar Sentinel, the newsletter of the Grand Traverse Astronomical Society, about zodiacal light.

One of the hardest of the night sky phenomena to spot is zodiacal light. The top picture above is my last photo of the zodiacal light. The photo is showing it brighter than it looks to the naked eye.
Zodiacal light is seen in the west in the evening in late winter and early spring and in the east in the morning in late summer and early autumn. The axis of the glow is near the ecliptic, the plane of the Earth’s orbit, along which lie the constellations of the zodiac.
This glow seems to have been first recorded by the Arabs around 630 CE. It was first recognized as a morning phenomenon as a false dawn, appearing before the first real glow of astronomical twilight. This false dawn was a big deal for the Islamic faithful, whose morning prayers must be made after the true dawn, or astronomical twilight, when the center of the Sun is 18° below the horizon.
How I usually recognize that I’m looking at the zodiacal light is kind of like not seeing the forest for the trees. That is, in certain parts of the sky, the sky doesn’t seem as dark as other parts. It helps to know where the zodiacal light is supposed to be. Once found, you’ll know what to look for, so finding it in the future will be easier.
In February 2017, on a relatively warm, but clear night, I went out to the Dune Climb at the Sleeping Bear Dunes. Part of the parking lot was plowed. I set up my tracking mount with my 5” scope that had a camera mount to photograph Orion and the Milky Way around Cassiopeia, Perseus and Taurus.
Having not thought about zodiacal light at the time, but while examining and processing the images later on, I began to notice that parts of the sky background not associated with the Milky Way were not as dark as I expected. It was on the side of the Milky Way closest to the ecliptic. These were telephoto shots, so the pyramidal shape of zodiacal light was not apparent. However, in recreating the sky at the time of the observations using Stellarium, it confirmed that it was the area where zodiacal light would be present.
What causes zodiacal light? The cause is dust, micron sized dust from comets and asteroids. Most of these lie in and near the plane of the solar system, which is why zodiacal light is centered on the ecliptic and the constellations of the zodiac and increases in brightness toward the Sun.
The free planetarium program Stellarium (stellarium.org) has added a zodiacal light effect in recent releases. Click on the Sky and viewing options icon at the left edge of the window, In the Sky tab there is a checkbox for zodiacal light and an intensity value to be selected. In order to see the effect, the Atmosphere icon at the bottom of the viewing window must be turned off. The effect is very subtle.
It is best seen around the vernal equinox in the evening and autumnal equinox tn the morning because at these times the ecliptic is closest to vertical. In the evening it tilts to the left, in the morning it tilts to the right. The closer one is to the equator, the more vertical the zodiacal light will appear. It would be a year-round phenomenon for observers in the tropics.
As an aside, Brian May, lead guitarist for the rock band Queen, with an uncanny resemblance to Sir Isaac Newton, earned a PhD in astrophysics in 2007 with his dissertation: A Survey of Radial Velocities in the Zodiacal Dust Cloud. It analyzed the motions of the particles of dust that make up the zodiacal dust cloud, which produces zodiacal light.
The best time to see this phenomenon will be the last week of March to the first few days of April 2022, before the Moon is a couple of days old.

03/23/2020 – Ephemeris – See zodiacal light in the evening

Ephemeris for Monday, March 23rd. Today the Sun will be up for 12 hours and 20 minutes, setting at 7:59, and it will rise tomorrow at 7:37. The Moon, 1 day before new, will rise at 8:11 tomorrow morning.

With the bright moon out of the sky for a few more nights it’s time to look for the zodiacal light in the evening. It’s is a faint but towering glow that can be seen after the end of astronomical twilight on moonless nights. It is seen in the west in the evening in late winter and early spring and in the east in the morning in late summer and early autumn. The axis of the glow is the ecliptic, the apparent annual path of the Sun in the sky, along which lie the constellations of the zodiac. Right now the end of astronomical twilight is about 9:41 p.m. and advancing at a rate of a minute or two each night. Go to a spot with a dark western sky, no big cities or towns out that way. Zodiacal light is caused by dust spread out around the Sun.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Much enhanced Zodiacal Light from the my back yard at 9:31 p.m. March 16, 2018, 5 minutes after the official end of astronomical twilight. Canon EOS Rebel T5 18mm f.l., f/3.5, 6 sec. ISO 12,800 . The clouds on the left appear to be illuminated by the lights of the towns of Beulah and Frankfort 20+ miles away.

03/25/2019 – Ephemeris – Zodiacal light is visible in the west again

Ephemeris for Monday, March 25th. Today the Sun will be up for 12 hours and 24 minutes, setting at 8:01, and it will rise tomorrow at 7:35. The Moon, 3 days before last quarter, will rise at 1:37 tomorrow morning.

With the bright moon out of the sky for nearly two weeks it’s time to look for the zodiacal light. It’s is a faint but towering glow that can be seen after the end of astronomical twilight on moonless nights. It is seen in the west in the evening in late winter and early spring and in the east in the morning in late summer and early autumn. The axis of the glow is the ecliptic, the apparent annual path of the Sun in the sky, along which lie the constellations of the zodiac. Right now the end of astronomical twilight is about 9:45 p.m. and advancing at a rate of a minute or two each night. Go to a spot with a dark western sky, no big cities or towns out that way. Zodiacal light is caused by dust spread out around the Sun.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Much enhanced Zodiacal Light from the my back yard at 9:31 p.m. March 16, 2018, 5 minutes after the official end of astronomical twilight. Note the Pleiades top left of center and the constellation of Ares below and right of center. Canon EOS Rebel T5 18mm f.l., f/3.5, 6 sec. ISO 12,800 . The clouds on the left appear to be illuminated by the lights of the towns of Beulah and Frankfort 20+ miles away.

I’ve added the approximate ecliptic line from a Stellarium view of the same date and time.

03/04/2019 – Ephemeris – Zodiacal light is especially visible this time of year

Ephemeris for Monday, March 4th. Today the Sun will be up for 11 hours and 18 minutes, setting at 6:34, and it will rise tomorrow at 7:13. The Moon, 2 days before new, will rise at 7:07 tomorrow morning.

Zodiacal light is a faint but towering glow that can be seen after the end of astronomical twilight on moonless nights. It is seen in the west in the evening in late winter and early spring and in the east in the morning in late summer and early autumn. The axis of the glow is the ecliptic, the apparent annual path of the Sun in the sky, along which lie the constellations of the zodiac. Right now the end of twilight is about 8 p.m. and advancing at a rate of a minute or two each night. The cause of zodiacal light is dust, micron sized dust from comets and asteroids. Most of these lie in the plane of the solar system, centered on the ecliptic and the constellations of the zodiac and increases in brightness and width toward the Sun.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Much enhanced Zodiacal Light from the my back yard at 9:31 p.m. March 16, 2018, 5 minutes after the official end of astronomical twilight. Canon EOS Rebel T5 18mm f.l., f/3.5, 6 sec. ISO 12,800 . The clouds on the left appear to be illuminated by the lights of the towns of Beulah and Frankfort 20+ miles away.

This is my previous best photo of zodiacal light. Zodiacal Light and Comet Hale-Bopp April 1997. Enhanced contrast.

The latest versions of Stellarium also show zodiacal light, but to see it the atmosphere needs to be turned off.  That’s keyboard shortcut A.

04/03/2018 – Ephemeris – How to spot Zodiacal Light

Ephemeris for Tuesday, April 3rd. The Sun will rise at 7:19. It’ll be up for 12 hours and 53 minutes, setting at 8:12. The Moon, 3 days past full, will rise at 11:44 this evening.

Zodiacal light is a faint but towering glow that can be seen after the end of astronomical twilight on a moonless night. It is seen in the west in the evening in late winter and early spring and in the east in the morning in late summer and early autumn. The axis of the glow is the ecliptic, the plane of the Earth’s orbit, indeed that of all the planets, along which lie the constellations of the zodiac. Right now the end of twilight is about 10 p.m. and advancing at a rate of a minute or two each night. The cause of zodiacal light is dust, micron sized dust from comets and asteroids. Most of these lie in the plane of the solar system, which is why zodiacal light is centered on the ecliptic and the constellations of the zodiac and increases in brightness and width toward the Sun.  Spotting Zodiacal Light takes dark adapted eyes,  time and patience.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Much enhanced Zodiacal Light from the my back yard at 9:31 p.m. March 16, 2018, 5 minutes after the official end of astronomical twilight. Canon EOS Rebel T5 18mm f.l., f/3.5, 6 sec. ISO 12,800 . The clouds on the left appear to be illuminated by the lights of the towns of Beulah and Frankfort 20+ miles away.  Note the Pleiades at the top of the image.

 

03/30/2017 – Ephemeris – Have you ever seen zodiacal light?

Ephemeris for Thursday, March 30th.  The Sun will rise at 7:26.  It’ll be up for 12 hours and 41 minutes, setting at 8:07.  The Moon, 3 days past new, will set at 11:23 this evening.

After you spot the moon tonight, hang around outside at the end of astronomical twilight, about 9:50 p.m. look to the west at Taurus the bull and Gemini, trying to block out the Moon.  Then broaden your gaze.  There will be a very faint triangular glow with broad base at the horizon leaning a bit to the left, with its apex near the V of the face of Taurus the bull and the bright star Aldebaran to the right of Orion.  This glow is called Zodiacal Light, caused by the reflected sunlight off a cloud of dust located in the plane of the solar system.  Most of the large bodies of the solar system orbit the sun close to a single plane.  Zodiacal Light is best seen on spring evenings and autumn mornings where it tilts to the right.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Zodiacal Light and Comet Hale-Bopp April 1997. My image.

03/03/2016 – Ephemeris – How to spot Zodiacal Light

Ephemeris for Thursday, March 3rd.  The Sun will rise at 7:15.  It’ll be up for 11 hours and 17 minutes, setting at 6:33.   The Moon, 2 days past last quarter, will rise at 4:00 tomorrow morning.

There is a faint glow in the west that lingers after the end of twilight. It is visible to the careful observer.  It’s Zodiacal Light, the reflected glow from countless bits of dust in the plane of the solar system.  Its glow can be seen after twilight officially ends at 8:11 p.m.  You’ll need to go to a spot with no towns or cities immediately to the west of you.  The glow will appear as a thin pyramidal glow tilted to the left.  It’s very difficult to find the first time, but once seen you’ll easily find it again.  Zodiacal Light is easiest seen on spring evenings and autumn mornings when the ecliptic, the path of the planets and zodiac are nearest to vertical.  The farther south one goes the easier it is to see.  I first saw it when I was stationed in the Air Force in Louisiana.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Zodiacal Light and Comet Hale-Bopp April 1997. My image.

Zodiacal Light and Comet Hale-Bopp April 1997. Enhanced contrast.

I find I have better luck photographing Zodiacal Light if I take  picture in its general direction of something else.

 

04/01/2014 – Ephemeris – Viewing Zodiacal Light

Ephemeris for April Fools Day, Tuesday, April 1st. The sun will rise at 7:23. It’ll be up for 12 hours and 46 minutes, setting at 8:09. The Moon, 2 days past new, will set at 10:37 this evening.

There is a faint glow visible to the careful observer at twilight’s end at 9:51 p.m. This glow is in the west. It’s Zodiacal Light, the reflected glow from countless bits of cometary dust in the plane of the solar system. You’ll need to go to a spot with no towns or cities immediately to the west of you. The glow will appear as a thin pyramidal glow tilted to the left. It’s tough to find the first time, but once seen you’ll easily find it again. A recent study of the glow confirms the source of it. While bright comets are fairly rare, small comets are very plentiful, including plenty that graze the sun and evaporate liberating their dust into interplanetary space. After tomorrow night the Moon will interfere for two weeks.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

I could never photograph Zodiacal Light when I wanted to.  However I did catch it inadvertently.

Zodiacal Light and Comet Hale-Bopp April 1997. My image.

Zodiacal Light and Comet Hale-Bopp April 1997. Enhanced contrast.

04/04/2013 – Ephemeris – Can you spot Zodiacal Light?

Ephemeris for Thursday, April 4th.  The sun will rise at 7:17.  It’ll be up for 12 hours and 56 minutes, setting at 8:14.   The moon, 1 day past last quarter, will rise at 4:34 tomorrow morning.

After you try to spot Jupiter tonight, or hang around outside at the end of astronomical twilight, about 10 p.m. look to the west at Taurus the bull and Gemini.  Then broaden your gaze.  There will be a very faint triangular glow with broad base at the horizon leaning a bit to the left, with its apex near Jupiter and the V of the face of Taurus the bull and the bright star Aldebaran to the right of Orion.  This glow is called Zodiacal Light, caused by the reflected sunlight off a cloud of dust located in the plane of the solar system.  Most of the large bodies of the solar system orbit the sun in a single plane.  The one exception to this are comets, which orbit at all angles to the sun.  Zodiacal Light is best seen on spring evenings and autumn mornings.

Addendum

It seems the only good photographs of zodiacal light I get is when there’s a comet in that direction.  It happened a year before with Comet Hyakutake.  The images here were taken later in the month when the Hyades and the Pleiades were lower in the sky.

Zodiacal Light and Comet Hale-Bopp April 1997. My image.

Here’s a black and white image with enhanced contrast.

Zodiacal Light and Comet Hale-Bopp April 1997. Enhanced contrast.