Categories: Astronomy

Catch New Galactic Nova Herculis 2021 in Hercules the Hero

Now’s the time to catch Nova Herculis 2021, before it fades from view.

…And then, there were two. Fresh off of the eruption of Nova Cassiopeiae 2021 early this year, another galactic nova made itself known earlier this past weekend, as a ‘new star’ or nova flirted with naked eye visibility in the constellation Hercules the Hero on its border with Aquila the Eagle.

The Discovery: The nova was discovered at +8th magnitude ‘with a bullet’ on the night of June 12th by astronomer Seiji Ueda from Hokkaido, Japan. The nova initially gained the telephone number-like monikers TCP J18573095+1653396 (denoting its position in the sky), and ZTF (Zwicky Transient Facility) 19aasfsjq (another alphabet soup designation), before getting the much more straightforward designation of Nova Herculis 2021, or simply N Her 2021. Just a few days ago, the American Association of Variable Star Observers (AAVSO) released the formal Alert Notice 745, notifying observers that a new bright northern hemisphere nova was indeed afoot.

The story thus far: This one came up fast, as Nova Her 2021 topped out at magnitude +5.5 on Sunday, June 13th, just a day after discovery. As of writing this, the nova has faded a bit but is still sitting at a respectable magnitude +9, worth hunting for with binoculars or a small telescope. Keep in mind, if history sets any precedent, Nova Her 2021 could well brighten again… and soon. Just look at how it flared and faded in this amazing sequence:

Nova Her 2021’s position in the sky: First, the good part: the region hosting Nova Her 2021 is currently rising to the east for northern hemisphere observers at sunset in mid-June. With the Moon waxing towards Full on June 24th, the time to catch Nova Her 2021 is tonight.

The nova’s position in the sky is:

Right Ascension 18 hours 57’ 31”

Declination +16 degrees north, 53’ 40”

The general field of view for Nova Her 2021 (centered on the Telrad finder). Credit: Stellarium/Dave Dickinson.

…and here’s a narrow, two degree wide finder chart:

N Her 2021 finder. Note that FF Aquilae is the brightest star in the field, just north of center. Credit: AAVSO.

The nova is very near (less than one degree away from) the +5.3 magnitude variable star FF Aquilae. Note that the famous ‘Coat-Hanger’ asterism is in the same general field of view:

Nova Herculis (marked) in the center of the field of view. Credit: Filipp Romanov

The nova’s position in the galaxy: Like extra-galactic supernovae seen in other galaxies, galactic novae tend to flare in a predicable fashion, making them good standard candles to roughly gauge distance. Based on this, Nova Her 2021 seems to be about 18 to 20 kilo light-years (kly) distant, in the Sagittarius Arm of the galaxy, offset from the direction from the core of the Milky Way and about five degrees north of the galactic plane.

Possible location (based on direction and brightness) for Nova Herculis 2021 in the Milky Way Galaxy. Credit: NASA

What exactly is Nova Herculis 2021? Galactic novae occur when a white dwarf star accretes material from a large nearby main sequence star. This material builds up, compresses, and ultimately gives way to a violent runaway fusion process, igniting in a brilliant flash over a period of several weeks. U Scorpii and T Pyxidis are members of a rare sub-category of variable stars known as recurrent novae.

An eVscope capture of Nova Herculis 2021. Credit: Mario Billiani

How common are novae seen in our galaxy? On average, a dozen or so novae are cataloged in our galaxy every year; once every decade or so, we get a good naked eye nova, which may top out as bright as magnitude +1, rivaling all but the very brightest stars, briefly changing the outline of the host constellation. The last such example was Nova Delphini 2013 in the tiny constellation of Delphinus the Dolphin.

Be sure to check out Nova Herculis 2021 while you can!

David Dickinson

David Dickinson is an Earth science teacher, freelance science writer, retired USAF veteran & backyard astronomer. He currently writes and ponders the universe as he travels the world with his wife.

Recent Posts

Russia Just Launched a New Science Module to the Space Station

The International Space Station (ISS) is about to get a little bigger. On July 21,…

55 mins ago

A new Balloon-Based Observatory Could Produce Images as Fine as Hubble

Launching satellites is an expensive business - at least for now.  But satellites are necessary…

2 hours ago

Forget About Interstellar Flights. Tiny Light Sails Could be Used to Explore the Solar System Today

Solar sails have been receiving a lot of attention lately.  In part that is due…

3 hours ago

The Moon has Been Mildly Preventing Coastal Erosion, in the 2030s, That Protection Ends

According to a new study, the Moon will be entering an orbital phase by the…

22 hours ago

Scientists Have a new way to Predict the Most Damaging Solar Storms

Space is full of hazards.  The Earth, and it’s atmosphere, does a great job of…

1 day ago

Micrometeorites Churn up the Surface of Europa. If you Want to Find Life, You’ll Need to dig Down a Meter or So

According to new research, impact craters caused by micrometeorites are the best place to look…

2 days ago