Journals / International Electronic Journal of Geometry / 2026 / Volume: 19 Issue: 1

Deforming the Nephroid into the Cayley Sextic and Beyond

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Publication Date
2026-04-22
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AI Summary & Key Takeaways

AI Insight
⚡ TL;DR(Too Long; Didn't Read)

When $d=0$ this curve is a nephroid, when $d=3r/2$ it is a Cayley sextic.

📌 3 Key Takeaways

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Objective & Hypothesis:In $\mathbb{R}^2$, let $\Gamma$ be a fixed circle with centre $C$ and radius $r$, and $\ell$ a straight line at distance $d$ of $C$.
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Key Findings & Data:We study the curve which is the envelope of the circles whose centre lies on $\Gamma$ and which are tangent to $\ell$.
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Conclusion & Impact:When $d=0$ this curve is a nephroid, when $d=3r/2$ it is a Cayley sextic.
🔬Design:Research Article
📍Scope:Comprehensive Sample
⚙️Variables:Envelope · circles · tangent line

Abstract

In $\mathbb{R}^2$, let $\Gamma$ be a fixed circle with centre $C$ and radius $r$, and $\ell$ a straight line at distance $d$ of $C$. We study the curve which is the envelope of the circles whose centre lies on $\Gamma$ and which are tangent to $\ell$. When $d=0$ this curve is a nephroid, when $d=3r/2$ it is a Cayley sextic.

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Cite This Article

Vieli, F. J. G. (2026). Deforming the Nephroid into the Cayley Sextic and Beyond. International Electronic Journal of Geometry, Volume: 19 Issue: 1. https://doi.org/10.36890/iejg.1793372

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References (9)

  1. Beardon, A. F., Beardon, L. A.: Circles, chords and epicycloids Math. Gaz. 73, 192–196 (1989). https://doi.org/10.2307/3618437
  2. Bruce, J. W. and Giblin, P. J.: Curves and singularities (2nd edition). Cambridge University Press, Cambridge (1992).
  3. Gomes Teixeira, F., Traité des courbes spéciales remarquables planes et gauches (reprint), Volume II. Chelsea Publishing Company, New York (1971).
  4. Königsberger, K.: Analysis I. Springer Verlag, Berlin (1999).
  5. Lawrence, J. D.: A catalog of special plane curves. Dover Publications, New York (1972).
  6. Lockwood, E. H.: A book of curves. Cambridge University Press, Cambridge (1961).
  7. Sloane, N. J. A.: The on-line encyclopedia of integer sequences, published electronically at https://oeis.org (2025).
  8. Umehara, M., Saji, K., Yamada, K.: Differential geometry of curves and surfaces with singularities. World Scientific, New Jersey (2022).
  9. Wang, Y., Nishimura, T.: Envelopes created by circles families in the plane J. Geom. 115 (7) (2024). https://doi.org/10.1007/s00022-023-00708-z