You did it! We figured this one out! It is a truth universally acknowledged (by me for certain) that the Bitchery pretty much knows everything, and really, it's true. Scroll down to see the solution for this HaBO - and many thanks!

This HaBO is from Yulin and I have a feeling someone definitely knows this HaBO:
I’ve recently rediscovered my love of romance novels and ripped through the works of Sherry Thomas, Joanna Bourne, and Eloisa James. But I’m trying to find the author/book that first introduced me to the genre many years ago…
It was a historical romance (set in 1800’s England?). I borrowed it from a friend around 2004 or 2005. It had a dark blue cover that opened out to reveal a man and a woman dancing under a starry sky. The author’s name was pretty prominent in swoopy, raised lettering. I think it had either a “C” or an “L” or an “S” in it.
The heroine has a misshapen foot/leg that she’s self-conscious about, and I think the hero might be a blonde rake named Jamie. Or Jaime. There may have been a telescope involved, people called her a bluestocking, and I think they had sex under the pretense of “lessons.” The hero has a tortured backstory because of time spent in foreign lands; I think his mother was a whore.
The heroine has a beautiful sister who has a sequel-bait side plot of falling in love with a studious man of science, who might have gotten her pregnant. I think the sequel by the same author is about the sister being a single mother and reconnecting with her lover.
If nothing else, can anyone recommend some historical romances featuring estranged lovers that reconnect and first hate each other and then fall in love, in the vein of Sherry Thomas’ Private Arrangements or Joanna Bourne’s The Black Hawk?
A HaBO and recommendation post in one!

I don’t know what it is, but I want to read it!!!!
Sounds like a Mary balogh I read years ago but I’m not convinced I’m right
Did she injure her foot in a fire? This sounds so familiar. Lisa Kleypas, maybe?
Could it be Dancing at Midnight by Julia Quinn?
The Balogh one is Red Rose. The hero is definitely tortured but he’s not named Jamie and there’s no telescope involved. She’s an excellent musician. Her sister is the beautiful one and they’ve been made the hero’s wards even though both sisters are older. Heroine has a bad foot/leg. I really liked this one but for those who mind it, the hero keeps his mistress through most of the book.
There’s also one of the Balogh’s from the Survivor’s Club series – the first one – The Proposal? Heroine with bad leg. But again, no telescope and no beautiful sister (at least in that book, from what I recall the heroine’s family pops up in some other Balogh’s…).
Halfway to Heaven by Susan Wiggs?
I’ve just added Halfway to Heaven to my TBR pile. Looks like 2016 is going to be a busy year!
Why can’t I search my ebook library for the word “telescope” and narrow it down? It’s almost certainly not the same book (since I remember none of the other details), but I know I read one in which he took her to his observatory and showed her his enormous telescope (ahem) in a Beauty & The Beast library kind of moment, and they were using his childhood schoolroom in the mansion for some kind of nonsexual tutoring that turned into sexual tutoring.
Times like these, I really regret not shelving everything on Goodreads by memorable props and locations.
@Ren Benton – that sounds like Sherry Thomas’s The Luckiest Lady in London.
It’s definitely Halfway to Heaven by Susan Wiggs. It’s actually set in 1870s Washington, DC, and the heroine’s father is a senator. She’s a budding astronomer and the hero helps her as she looks for a comet. It’s a good read, and there are a few other books in the series.
Go Team HaBO!
Yulin, I’d rec Julia Quinn’s Everything and the Moon–it has the sort of plot you’re asking about.
@Georgie: You are GOOD.
She asks him to teach her Newtonian mechanics so she can locate heavenly bodies.
“See, this is why so many gentlemen never marry. You get yourself a pretty wife, you spend half of your waking hours pleasuring her; then you spend the other half eradicating her ignorance. Soon your estate smolders in neglect and your personal hygiene suffers. Your tenants complain, your staff depart, and your wife won’t let you near her anymore because you are poor and malodorous.”
“I had eleven pounds and eight shillings of emergency money set aside,” she said briskly. “I will earmark it for soap, so you never need to reek, no matter how poor you become.”
#nerdlove
Manga Collins’ How to Romance a Rake in the Ugly Ducklings series features a bluestocking heroine who lost her foot after an accident.
Could it be. Dancing with Clara by Mary Balogh?
https://www.amazon.ca/Mary-Balogh-Dancing-Regency-Romance/dp/B00IBT45TO/ref=sr_1_10?ie=UTF8&qid=1484068958&sr=8-10&keywords=Dancing+with+clara
@Sarah is completely right, it’s got to be Halfway to Heaven by Susan Wiggs, one of a series of books about the Calhoun family (I think that’s their name)
@Ren and Georgie
Doomed! I am doomed to never be able to sleep again! Too many terrific books, so little time!
Dang it! This is what I get for neglecting my blog reading. I agree with the other commenters that it’s Halfway to Heaven by Susan Wiggs – although I don’t recall the heroine having a deformed foot and/or leg and the “lessons” are sort of a cross between Cyrano de Bergerac and My Fair Lady in that Jamie ends up falling for Abigail by aiding her in trying to catch the eye of the man she fancies herself in love with.
The sequel baiting sister (Helena) gets her own story in Enchanted Afternoon.
Christi Caldwell’s ‘To Redeem a Rake’? Opens with the heroine breaking her leg as a child. It heals improperly and causes a limp and deformity. Hero was her childhood friend who grew into ‘tortured hero’ type who got wrapped up in his own manpain and ignored his friend to such an extent that he missed her season (even though both were in London at the same time). I think the hero had a sequel bait sister. Heroine became sequel bait’s companion.
eager to learn which book it is
Thanks to this HABO, I’m halfway through Halfway to Heaven and really enjoying it. I’m sort of surprised I hadn’t come across it before since it’s got so much of what I love in a historical.
I’ve also added Luckiest Lady in London to my TBR stack. It’s funny. I’ve only read one Sherry Thomas, Ravishing the Heiress, based on something that I read here. I absolutely loved that book. But the covers, titles and summaries for her books are total turn-offs for me. I think I need to get over that. Or her publisher needs to do something. Having said that, her latest looks much better and based on the reviews, it’s going to have to go in the TBR stack too. Sigh.
This totally sounds like Karen Robards book Scandalous which was the first in the Banning Sisters Trilogy.
https://www.goodreads.com/book/show/728452.Scandalous?from_search=true
The original cover was definitely dark blue and I remember the heroine Gabby walked with a limp (it was either her foot or hip) as a result of a childhood injury.
@hopeful puffin – I totally know what you mean about Sherry Thomas’s books – I skipped them for a long time because for some reason I had decided they weren’t for me… that said, I highly recommend just putting that thought aside and settling in for some awesome reading. I’m seriously envious that I can’t read them all again for the first time.
Yesssss, it’s Halfway to Heaven by Susan Wiggs!!! Thank you! I will definitely be checking out the rest of these recs as well!