Cometary Activity Campaign for April & May 2022 (beta program)

Unistellar is currently extending our citizen science programs to comets. The new Cometary Activity is currently at the beta stage, and will evolve and improve over the coming months, thanks to your feedback.

Update: Unfortunately C/2021 O3 (PanSTARRS) did not survive its trip around the Sun. We hope everyone had a chance to enjoy it in the brief time C/2021 O3 (PanSTARRS) was visible! Instead, we suggest observing one of the other campaign comets this month!

Comet C/2021 O3 (PanSTARRS) is passing by the Sun. This comet is big and expected to hit 9th magnitude (JPL estimate) near the end of April. It’s possible this comet won’t survive its trip around the Sun, so keep an eye on it to see if it flares! Assuming it survives C/2021 O3 (PanSTARRS) will be above the horizon and visible for the whole month of May.

Quick facts about C/2021 O3 (PanSTARRS):

  • Shortly after its discovery last year it was confirmed to already be active. This suggests the nucleus is quite large.
  • If this comet doesn’t survive its trip near the Sun, it will flare up as it breaks apart. Going out with a bang!
  • The best time to view this comet will be just after it passes by the Sun, around May 5th – May 7th.

View of the orbit of C/2021 O3 as it passes through the solar system. Video provided by Tony Dunn.

View of C/2021 O3 from Earth as it passes through the solar system. Video provided by Tony Dunn.

Comet C/2017 K2 (PanSTARRS) is approaching. This comet is currently on its approach to the Sun. It’s closest approach to Earth will occur in July but C/2017 K2 (PanSTARRS) is visible now and expected to stay that way throughout the summer!

Quick facts about C/2017 K2 (PanSTARRS):

  • It’s closest approach to Earth will be on July 14th, 2022
  • The coma on C/2017 K2 (PanSTARRS) is massive, with a diameter nearly as big as Jupiter!
  • At the time of its discovery C/2017 K2 (PanSTARRS) was the furthest active comet. It was already active at a distance of 16 AU from the Sun!

You can easily find C/2017 K2 (PanSTARRS) in the Unistellar app’s database.

To observe C/2017 K2 (PanSTARRS):

  • Follow the HowTo Guide for A. The comet is in the app’s database and you’re observing it via the Science Observation mode
  • In the Recording field, enter the following information for

    Exposure time: 3971 ms
    Gain: 25 dB
    Duration: 10m 00s
  • At the end of the acquisition, record a dark frame with the dust cap on.

View of the orbit of comet C/2017 K2 as it passes through the solar system. Video provided by Tony Dunn.

View of the comet C/2017 K2 as seen from Earth. Video provided by Tony Dunn.

Comet C/2019 L3 (ATLAS) is coming in hot (cold?). This comet hit its peak brightness back in January but it will be visible throughout the months of April and May. Comets often have outbursts when nearing the Sun that can create changes in their orbit. Help keep an eye out so we’ll know where this comet is headed in the future!

Quick facts about C/2019 L3 (ATLAS):

  • It’s closest approach to the Sun was on January 9th, 2022
  • C/2019 L3 (ATLAS) is on a very slightly hyperbolic orbit. Unless the orbit changes this comet will be leaving our solar system.
  • When closest to the Sun, C/2019 L3 (ATLAS) was still over 3 astronomical units away!

C/2019 L3 (ATLAS) is NOT in the Unistellar app’s database.

To observe C/2019 L3 (ATLAS):

  • Follow the HowTo Guide for B. The comet is not in the app’s database and you’re observing it via the Science Observation mode.
  • You will need to compute the coordinates of the comet with our Ephemeris calculator. 
  • At the end of the acquisition, record a dark frame with the dust cap on.

Orbit of comet C/2019 L3 around the Sun, simulation by Tony Dunn.

View of comet C/2019 L3 from Earth, simulation by Tony Dunn.

The comet C/2019 T4 (ATLAS) has entered the solar system and will reach maximum brightness on April 10th. This comet is already quite bright and will be visible all the way through May. Try to catch it during an outburst so we can predict where it will head next.

Quick Facts about C/2019 T4 (ATLAS):

  • C/2019 T4 (ATLAS) is traveling from the very edges of the solar system
  • As of mid-March C/2019 T4 (ATLAS) has garnered less than 1000 catalogued observations at the Minor Planet Center. For comparison, C/2019 L3 (ATLAS) was discovered around the same time but has upwards of 4000 catalogued observations!
  • C/2019 T4 (ATLAS) was discovered by ATLAS, or the Asteroid Terrestrial-Impact Last Alert System

C/2019 T4 (ATLAS) is NOT in the Unistellar app’s database.

To observe C/2019 T4 (ATLAS):

  • Follow the HowTo Guide for B. The comet is not in the app’s database and you’re observing it via the Science Observation mode.
  • You will need to compute the coordinates of the comet with our Ephemeris calculator. 
  • At the end of the acquisition, record a dark frame with the dust cap on.

Orbit of comet C/2019 T4 around the Sun, simulation by Tony Dunn.

View of comet C/2019 T4 from Earth, simulation by Tony Dunn.