Astronomy in Middle-earth

Question

There already are a number of questions which discuss the relationship between "our world" and Middle-earth.

I am interested in the astronomy of Middle-earth, which I guess could possibly have discussed in some book. I am currently re-reading the LotR (I highly recommend to read it multiple times, and I feel to be not alone with this idea :) ) and am noticing a lot of nice details. Among these, there is this description at the end of Three is company:

Away high in the East swung Remmirath, the Netted Stars, and slowly above the mists red
Borgil rose, glowing like a jewel of fire. Then by some shift of airs all the mist was
drawn away like a veil, and there leaned up, as he climbed over the rim of the world,
the Swordsman of the SKy, Menelvagor whith his Shining belt.

Menelvagor with his Shining Belt could be Orion. This is consistent with the time of the year (autumn in the northern hemisphere). Is it possible to identify the other stars or planets? (Borgil, with a red hue, could be Mars).

Answer 1

Wikipedia has a good list of star references and more explicitly cross-referencing those with real life stars where provided. Those specifically cross-referenced I've included below, along with citations where possible:

• Alcarinque - Jupiter? (Morgoth's Ring)
• Borgil - Aldebaran? (A Definitive Identification of Tolkien's 'Borgil': An Astronomical and Literary Approach)
• Carnil - Mars? (Morgoth's Ring)
• Eärendil’s Star, Gil-Amdir, Gil-Estel, Gil-Oresetel, Gil-Orrain - From Letter 297:

Eärendil ... To my mind the A-S uses seem plainly to indicate that it was a star presaging the dawn (at any rate in English tradition) : that is what we now call Venus: the morning-star as it may be seen shining brilliantly in the dawn, before the actual rising of the Sun.

• Eksiqilta, Ekta - Orion’s Belt (Qenya Lexicon, Parma Eldalamberon 12)
• Elemmire - Mercury? (Morgoth's Ring)
• Helluin - From the Silmarillion:

Helluin The star Sirius

• Luinil - Uranus? (Morgoth's Ring)
• Lumbar - Saturn? (Morgoth's Ring)
• Menelvagor, Daimord, Menelmacar, Mordo, Swordsman of the Sky, Taimavar, Taimondo, Telimbektar, Telimektar, Telumehtar - Orion (Lord of the Rings, your reference above)
• Morwinyon - Arcturus (Book of Lost Tales)
• Nenar - Neptune? (Morgoth's Ring)
• Remmirath, Itselokte, Sithaloth - Pleiades (Lord of the Rings, your reference above)
• Valacirca, the Sickle of the Valar, Burning Briar, Durin’s Crown, Edegil, Otselen, the Plough, Seven Stars, Seven Butterflies, Silver Sickle, Timbridhil - Ursa Major / Big Dipper (Lord of the Rings, allegedly, but I can't find this beyond deduction from the description)
• Wilwarin - From the Silmarillion:

Wilwarin Name of a constellation. The word meant 'butterfly' in Quenya, and the constellation was perhaps Cassiopeia.