Last week, my husband and I celebrated* 12 years together.  Being the astronomy nerd that I am, I wanted to put an astronomical spin on this event, so I decided to look up what stars are 12 lightyears away from Earth. It turns out that Tau Ceti is about that distance from us (11.9 lightyears), which means that if I had looked up at Tau Ceti on the night of our anniversary, I would have been seeing light that was emitted when my husband and I first started going out.

When I posted this on twitter, Portsmouth physics graduate James Bremner came up with the genius idea of anniversary tea towels but in terms of lightyears to celestial objects.

@jen_gupta Idea for podcast merch. One of those anniversary teatowels, but the anniversary list in terms of light from celestial objects pic.twitter.com/rWUYUp8A2r

— Old Man Student (@StudentBremner) February 8, 2017

While tea towels would require more time and effort than I have right now, I thought for Valentine’s Day I would at least put together a list of astronomical anniversaries. As there aren’t that many stars near to our solar system, and it’s quite hard to figure out precise distances to stars, I’ve had to allow for some leeway with this!

• 1 year  Somewhere in the Oort cloud
• 2 years Still in the Oort cloud
• 3 years Almost out the Oort cloud (thanks @nialldeacon)
• 4 years  Alpha Centauri (4.37 lightyears)
• 5 years (nothing)
• 6 years Barnard’s Star (5.96 lightyears)
• 7 years WISE 0855−0714 (7.27 lightyears)
• 8 years Lalande 21185 (8.31 lightyears)
• 9 years Luyten 726-8 (8.73 lightyears)
• 10 years Ross 248 (10.3 lightyears)
• 15 years LP 145-141 (15.11 lightyears)
• 20 years Gliese 581 (20.4 lightyears)
• 25 years Vega (25.04 lightyears)
• 30 years Beta Comae Berenices (29.78 lightyears)
• 40 years Beta Trianguli Australis (40.37 lightyears)
• 50 years Mu Arae (49.8 lightyears)
• 60 years Beta Arietis (59.6 lightyears)

And in case you’re ever tempted to buy a card that’s along the lines of ‘I love you to the Moon and back’, in my mind that would be appropriate for a 2.6 seconds anniversary (lightspeed) or 6 days (Apollo 8 mission length)…neither of which I would really say are significant enough anniversaries to warrant a card!

*ordered Dominos pizza and had an otherwise totally normal evening.