Please take a moment or two to read the following, which explains what we provide and under what conditions; it is important that anyone wishing to book for a stargazing session at Hanwell understands these basic points.
Essentially, out under the open sky looking at it with some serious telescopes! Guided by members of our team, visitors will actually see for themselves a variety of interesting and beautiful celestial objects, through the telescopes of the Hanwell Observatory. This first-hand experience of the cosmos takes place 'out under the stars' in the open air, with each visitor taking a turn (or several) at the eyepiece: visitors are in immediate personal contact with both the sky & the telescope through which it is seen, not sitting indoors at a computer screen at one remove from that reality. As with any other such outdoor activity, these events are therefore subject entirely both to the elements and to the regular cycles of the natural world - so, in particular, dates & times cannot simply be chosen at will.
At present, HCO provides only nocturnal stargazings, these sessions lasting from 1 to 3 hours somewhere between 6pm & 11 It follows that the timing of these events is dictated by sunset and hours of darkness: during the winter season from late October to the last week of February we can start at 6 if required (or sometimes even earlier at midwinter, by special arrangement), the earliest possible start-time then becoming progressively later as the evenings draw out through the spring, until the onset of the 'summer closed season' on 20th May, when full nightfall is too late to have a worthwhile session by 11pm, this closed season lasting until 28th July at which point the cycle resumes, in reverse, through the autumn open season.
The only absolute constraints fixed from year to year are those just explained above but, beyond that, HCO does not generally run these events within 4 days either side of full moon because the Moon itself is then at its least interesting & impressive in a telescope, and it floods the night sky with light which obliterates the stars. Within these limits there are preferences to bear in mind with respect to the approx. 7 months of 'open season' remaining each year. In fact, the whole stargazing calendar revolves around the phases of the Moon and those fall at different dates each year, so there is no fixed calendar for these events: in each 29½-day lunar cycle the period of approx. one week extending from 3 days or so after the new moon, through first quarter, to day 10 is a 'Moon window' during which stargazing evenings can proceed with a good Moon; the fortnight from the end of the full-moon closed period to the resumption of the next Moon window is a 'no-Moon' or 'dark-sky' window, during which there are good stargazing opportunities without the Moon. We very strongly recommend that first-timers with no previous experience of the night sky through a telescope should make their first visit to a Hanwell stargazing during a Moon window, as the first-quarter Moon is certainly the most spectacular of all telescopic objects; no-Moon evenings, on the other hand, are much better for 'deep sky' objects such as galaxies, although these are inclined to be rather dim &disappointing to the beginner however impressive the idea may be. Further, for maximum impact, the best Moon windows are those from December to May, those in the autumn season being far less satisfactory, but other time-tabling considerations may often prevent attainment of this ideal. Lastly, the visibility of the more spectacular major planets - Venus, Mars, Jupiter, & perhaps most of all, Saturn with its rings - follows a different cycle for each one, none of which bears any simple fixed relationship to terrestrial calendar dates, so the desire to see one or other of these imposes further date-specific preferences which vary from year to year. The only constant in all of this - always the same on any given date, although changing with the seasons on a simple annual cycle - are the stars.
Anyone &everyone, whether or not they have ever looked through an astronomical telescope before: the general public. There is absolutely no need for the visitor to know anything whatsoever about astronomy or to have had any previous interest in the subject, as our sky-guides conduct these sessions without assuming any such knowledge on the part of visitors. HCO's prime mission is, in fact, to provide the 'cosmic experience' to those who have not enjoyed it before. Nonetheless, amateur astronomers and others with some previous experience are equally welcome and should also find these evenings very rewarding.
Children's groups: while the Hanwell stargazing evenings are for virtually all age-groups from 8 to 80 & beyond, and we make no special provision specific to younger visitors, these events are entirely suitable for accompanied children from 8 years upwards. Please note, however, that for sizeable groups of 8-11 year-olds HCO does require at least one responsible accompanying adult in the visitor group to every 3 children. We do ask accompanying adults in these cases to take active responsibility in managing the group, both in order to guarantee the children's full engagement with, & benefit from, the HCO experience and to avoid damage to the delicate instrumentation with which they will be in close contact. The experience is not suitable for under-8's except in individual cases of special enthusiasm, individually accompanied by a parent or parents.
Stargazing evenings are provided for a minimum of 10 visitors per event. On the Hanwell main site itself the static facilities can cope with a maximum of 25 visitors, in order to avoid excessive queuing-time for a turn at the eyepiece. Larger groups can be occasionally accommodated by special arrangement, however, using smaller portable instruments elsewhere on the Hanwell site, or at other venues. This is generally only something that HCO does in association with other educational &outreach organizations but if you would like us to run such an event, just ask - and please give us at least two months notice in such cases.
From autumn 2010, when the 30 inch reflector at Hanwell is fully commissioned for public use, HCO will provide a regular calendar of public stargazing events using this large telescope, on dates pre-set by us & advertised well in advance. These public evenings will be open to all on an individual-booking basis, such prior booking being simply to limit visitor numbers to the maximum of 25 per evening, and admission will be free. These events cannot be booked for the exclusive benefit of any particular group and their advertised dates are non-negotiable. If, on the other hand, you wish to book a private 'star-party' at the Hanwell Observatory on another astronomically-possible date (see 'Dates' above), this can be done by prior arrangement, provided that there are sky-guides available for that date. The admission charge for private star-parties is £2.50 per head subject to a minimum total of £30, payable only if the event proceeds; all receipts from such private evenings are used to finance the HCO public outreach programme. Both the private & public events are subject to the principles & conditions set out above.
For private star-parties, initial enquiries can be made by telephoning 01295730762 (answering machine), or via e-mail (info@hanwellobservatory.org.uk). For the public evenings, an online booking system will be set up on this website when the regular programme of such events commences.
Telescopes cannot see through clouds any more than eyes can. These events are wholly weather-dependent and can proceed only if at least 70% of the sky is completely clear. Consequently, any particular stargazing evening will go ahead if & only if the weather-prospects appear favourable; at present, a message of confirmation, or otherwise, is put up on the telephone line above at 3p.m. on the day in question, so if there is the slightest doubt, intending visitors should 'phone that number before setting out for Hanwell; when the full public programme & its online booking system come on-stream, some system for notification of would-be visitors will be set up on this website. In the event of cancellation, HCO will endeavour to accommodate those booked for the cancelled event at a later date.