This is an awkward time of year for astrophotography. It only gets really dark after the end of “astronomical twilight”, when the Sun dips 18 degrees below the horizon. That didn’t happen until quarter past midnight last night, and by 2am it was back above that 18 degree line. The longest day / shortest night is still six weeks away, so for the next twelve weeks the night sky will be at least as testing as it is now.
These photos were taken in the hour around 1am last night, from the long layby set back from the A591 east of Staveley.
First, the constellation Cepheus:
The 50mm lens gives a 27×18-degree field of view on the D90, so just enough space to accommodate the whole of Cepheus as PANSTARRS (mag 7.2) approaches from Casseopeia.
At ISO 800 all the numbered stars in Cepheus are fully illuminated on the screen, including Erakis (mag 4.1), the “Garnet Star” on the right.
On to PANSTARRS with the 300mm lens:
Two questions are answered here. First, does a stack of two 4-minute frames deliver more than a single 8-minute frame (all other settings unchanged) or is it the other way round? Decide for yourself, but I think there’s more refinement in the layered 4-minute frames and more punch in the single 8-minute frame.
Second, can the EQ3-2 mount track accurately for 8 minutes loaded with the D90 and a 300mm lens? Looks good to me.
At 2am it’s getting light in the east (!!) so time to pack up. I’ve had great fun photographing PANSTARRS over the last few weeks and learned many lessons along the way, but this is probably the last session, given the combination of short, late nights and uncertain Cumbrian weather.