Hello,

Bernadette Brady, Brady's Book of Fixed Stars (1998), Page 332

Heliacal setting: The star setting as the sun rises. This marks the end of the period of curtailed passage...

BUT in most of the other places I looked in the net has the star setting with the sun. Which one is correct???

Thank you!

Hi Junaid

B. Brady's definition is confusing so I would forget that - what she is describing could be said of an acronychal rising of a superior planet (see my definition below).

I have an old article online which explains heliacal setting as part of the combustion cycle. That might be easier for you to refer to, to get a sense of the whole concept (2nd half of 1st page, rest of the article needs updating http://www.skyscript.co.uk/heritage/egyptians.html ). But I have also included my own quick definition of heliacal rising and setting below:

• Heliacal rising/setting: ancient astrologers gave particular emphasis to the heliacal rising and setting of stars since for every locality these repeat on the same calendar date each year. A heliacal setting occurs when a planet or star enters into conjunction with the Sun. The increasing proximity of the Sun towards the star each day leads to a period of invisibility, during which it is masked by the Sun?s light (see ?combust?). Its setting is the moment when it is visible for the last time immediately after sunset. It then rises and sets with the Sun, remaining hidden from sight both day and night. When the Sun has separated from the star by somewhere between 8-20 degrees of zodiacal longitude, the star begins to emerge, briefly, immediately before sunrise. Its first brief appearance, known as its heliacal rising, was an important feature of ancient ?star-calendars?, (known as parapegmas, from the Roman practice of noting the calendar by pegs in a town centre wall).

• Acronycal/acronychal: the rising of a planet at sunset (Gk: akro ?rise/height? + nychos ?night?). This term can be used of the inferior planets when they make their heliacal risings at sunset; (e.g., figure 19a, p.18, shows the ?true? acronychal ? sunset ? rising of Venus); or it can be said of the superiors when they are in opposition to the Sun and therefore rise over the ascendant as the sun sets. Paulus Alexandrinus defines the term in his Introductory Matters, ch.14.

To Deb,

Thank you for the prompt reply!