You might have seen my earlier publish asserting that we now have 4 new planet candidates found by Planet Hunters NGTS, if not you will discover it right here. We needed to present you some extra data on what we learn about every candidate to date and the efforts we’ve made to collect follow-up information as we work in direction of ascertaining whether or not or not they’re actual exoplanets! Step one as soon as we determined that these candidates had been worthy of additional investigation was to suit the information utilizing a extra intricate mannequin. That is sometimes what’s meant by phrases like “modelling estimates” or “match outcomes” that you could be see beneath or in different items of science communication. Every of those candidates pose their very own distinctive challenges in having the ability to verify whether or not they’re actually planets, nevertheless to have already got 4 planet candidates is a promising signal for the way forward for the mission and an actual testomony to the good work put in by you, the Planet Hunters NGTS volunteers.
Topic 69695263: That is our most promising candidate as far as the transits look fairly clear and our modelling estimates give encouraging outcomes. We expect it is a scorching Jupiter orbiting a “Ok dwarf star,” which is a star barely smaller and cooler than our Solar. We’ve estimated that the planet candidate has a radius equal to 1.09 instances the radius of Jupiter, which we write as Rp=1.09 RJup. It orbits its host star each 1.74 days which suggests by the point you flip 18 Earth-years-old, you’d be nearly 3800 years-old on this planet candidate (if it exists, and assuming you possibly can stay on it, which you’ll be able to’t). We’ve got obtained information from the Zorro crew for this candidate (learn extra concerning the Zorro instrument and our follow-up efforts right here), and it reveals that the host star is remoted from different stars so far as we are able to inform, which implies that we may be barely extra assured that this isn’t a false constructive sign brought on by an eclipsing binary! There’s nonetheless loads of work to do earlier than we are able to method the potential for confirming or validating this as a planet, however we’re cautiously optimistic about this candidate.
This candidate has been inflicting one thing of a headache since we solely managed to look at one full transit and a lot of partial transits (i.e. we solely see the beginning or finish of the transit). We’ve got estimated that the potential orbiting physique has an orbital interval of three.97 days nevertheless our radius estimates vary from Jupiter-sized as much as a radius not a lot smaller than our Solar. This implies we might have a planet candidate but it surely is also what’s often known as an eclipsing binary with low mass (EBLM). Whereas these are attention-grabbing techniques, they’re not the planets we’re in search of! We do have Zorro information for this candidate and we are able to’t see one other star close by nevertheless it’s doable that the sign might be a false constructive brought on by “systematics” which is a normal time period for any pattern within the information which may not have been accounted for throughout processing.
Very like the candidate above, this candidate is a difficult one. The transits look like grazing (take a look at this publish for an outline of grazing transits) which makes it tough to get estimate of the radius of the candidate. The radius of the planet candidate is estimated to be not less than Rp=1.50 RJup which is already on the higher restrict for what we consider is usually a planet. Our higher estimate of the radius is one photo voltaic radius, that means this might be a typical eclipsing binary. Sadly we don’t have Zorro information for this candidate to have the ability to test this simply but. This candidate, and the earlier one, would require some extra investigation to actually perceive what they really are.
Lastly, this candidate may be very thrilling as a result of if our preliminary estimates are right, this is able to be one in all solely a handful of discoveries thus far of big planets orbiting near their small host star. The transit depth of ~12% is way deeper than we sometimes anticipate for exoplanet transits, nevertheless the host star has a radius equal to only one/third the radius of our Solar. Due to this fact, we consider this might be a scorching Jupiter, with a radius of Rp=1.13 RJup, orbiting an M dwarf star on a 2.10 day interval. All these techniques are very uncommon and actually shocking to search out as a result of our present understanding of how planets type means that such a big planet shouldn’t be capable of type round such a small star as a result of there merely shouldn’t be sufficient time for it to type or planet constructing materials obtainable. The Zorro information for this candidate can be encouraging as we see no companion stars. We hope to collect extra information on this object within the coming months if doable, so keep tuned!
These 4 NEW candidates are actually thrilling! They weren’t noticed within the preliminary test of the information by the NGTS crew which implies that the Planet Hunters NGTS mission has confirmed it actually has the potential to be a complimentary search to assist NGTS uncover as many planets as doable. We couldn’t have carried out this with out the assistance of everybody who’s categorised topics on Planet Hunters NGTS and we’re desirous to see what else you possibly can assist us discover sooner or later as there are nonetheless loads of topics to be categorised! I’ll be presenting these candidates subsequent week on the UK Exoplanet Assembly in Edinburgh earlier than checking the most recent outcomes from the mission for extra doable planet candidates. We’ll even be beginning to write up the primary outcomes from the mission right into a paper to be submitted to an instructional journal!