Exoplanet HAT-P-6b (5/9/2020) – IMT3

Session period 19:00 – 01:18, transit start ~23:06 and end ~02:37

Before I move house, we are going to try and grab another exoplanet or two or possibly three…..we’ll see. Tonight whilst it is currently clear and due to cloud over by 1am, we will go for HAT-P-6b that is on alert from Exoclock.

Exoclock Exoplanet on Alert tonight

The transit end time is after it is due to cloud over but we may be able to get the start of the transit and some useful data to possibly half way through. So I have opened the dome, started to cool the 12″ down and slewed to a magnitude 4.29 star in the vicinity of Andromeda called HIP 116631 also known as 17 Iota Andromedae in the Flamsteed catalogue so that I can slew and centre on the object when it gets dark.

HIP 116631

I’ve now manually centred the star due to the brightness of the sky still and synced in The Sky X

Manually centred
HIP 116631 in relation to HAT-P-6b

I’m now waiting for a bit more darkness to perform the first focus run.

At 20:31 I performed a focus run on the mag 4.29 star with the red filter and got position 63007 @ HFR 5.2 and temperature at the focuser of 17.28℃.

Focus run on red filter

I have performed another solve and sync as I had left the scope running for a while without guiding and the star had moved slightly.

Solve and Sync on target

I have now taken a quick 20 second exposure of the target to confirm it was the right star as per the star chart from the Exoclock website and it was.

20s exposure of HAT-P-6b

I have started guiding on a nearby star with PHD2.


HAT-P-6b rising from the East as can be seen in TSX.

HAT-P-6b rising in the East

So here is a 2 minute exposure of the target. I tried 60 second but given I am running Gain 10 Offset 10 the maximum pixel count for the centre of the star was 1,648 out of 65k. So a 2 minute exposure produces 9,488 which is still low but I will continue on the low side for now. 1 hour before the transit is in about 45 minutes so I will wait then start gathering data.

2 minute exposure of HAT-P-6b

So we’ve started and set to run for 5.5 hours, this means a a meridian flip in 4 hours time so I will need to stay up until 2am, perform the flip then head back to bed.

First image down

The clouds have started to roll in, however so far we have been lucky and our star and planet are just outside the bank of cloud …… but for how long?


So it finally clouded over around 1am although the data for the past 20 minutes is suspect, so I hope we at least have the first half of the transit.