Astronomia
Orbital mechanics, cosmology, planetary science, astrophotography, and space exploration calculators.
Calcolatore Periodo Orbitale
Calculate the orbital period of a body circling a central mass using Kepler's relation T = 2pi * sqrt(a^3 / (G * M)).
Calcolatore Velocita Orbitale
Determine the orbital speed of a body in a circular orbit using v = sqrt(G * M / r).
Calcolatore Velocita di Fuga
Calculate the minimum speed needed to escape a celestial body's gravitational pull using v_esc = sqrt(2 G M / r).
Calcolatore Accelerazione Gravitazionale
Compute the surface gravitational acceleration of a celestial body from its mass and radius using g = G M / r^2.
Calcolatore Terza Legge di Keplero
Relate orbital period and semi-major axis for bodies orbiting the Sun using T^2 = a^3 (years and AU).
Calcolatore Trasferimento di Hohmann
Compute the two delta-v burns and transfer time for a Hohmann transfer orbit between two circular orbits.
Calcolatore Delta-v
Compute the delta-v available from a rocket stage using the Tsiolkovsky equation: dv = v_e * ln(m0 / mf).
Calcolatore Energia Orbitale Specifica
Find the specific mechanical energy of an orbit: epsilon = -G M / (2a).
Calcolatore Sfera di Hill
Estimate the Hill sphere radius within which a body's gravity dominates: r_H = a * (m / (3M))^(1/3).
Calcolatore Limite di Roche
Calculate the Roche limit, the minimum distance at which a self-gravitating satellite can orbit without tidal disruption.
Calcolatore Periodo Sinodico
Calculate the synodic period between two orbiting bodies: the time between successive conjunctions as seen from one body.
Convertitore Siderale-Sinodico
Convert a planet's sidereal period to its synodic period relative to Earth.
Calcolatore Velocita Satellite
Determine the speed and period of a satellite in circular orbit at a given altitude above Earth.
Calcolatore Orbita Geostazionaria
Compute the geostationary orbit altitude and speed for any planet given its mass and rotation period.
Calcolatore Eccentricita Orbitale
Compute the eccentricity of an orbit from its periapsis and apoapsis distances: e = (r_a - r_p) / (r_a + r_p).
Convertitore Anni Luce in Chilometri
Convert astronomical distances between light-years and kilometres. One light-year is the distance light travels in one Julian year.
Convertitore Parsec in Anni Luce
Convert distances between parsecs and light-years. One parsec is the distance at which 1 AU subtends 1 arcsecond of parallax.
Calcolatore Distanza di Parallasse
Calculate the distance to a star from its parallax angle: d(pc) = 1/p(arcsec).
Convertitore Unita Astronomiche
Convert between Astronomical Units (AU) and kilometres, miles, and light-minutes.
Calcolatore Velocita di Redshift
Estimate a galaxy's recession velocity from its cosmological redshift using the classical approximation v = z * c.
Calcolatore Distanza di Hubble
Estimate the distance to a galaxy from its recession velocity using Hubble's law: d = v / H0.
Calcolatore Tempo di Retrospezione
Estimate the lookback time (how far back in time you are seeing) from distance in megaparsecs, using t = d / c.
Calcolatore Dimensione Angolare
Compute the angular size of an object from its physical diameter and distance: theta = 2 arctan(d / (2D)), approximated as theta = d / D (radians) for small angles.
Calcolatore Magnitudine Apparente
Determine a star's apparent magnitude from its absolute magnitude and distance using the distance modulus: m = M + 5 log10(d/10).
Calcolatore Magnitudine Assoluta
Find a star's absolute magnitude from its apparent magnitude and distance: M = m - 5 log10(d/10).
Calcolatore Modulo di Distanza
Calculate the distance to a star from the difference between apparent and absolute magnitudes: d = 10^((m - M + 5) / 5).
Calcolatore Luminosita
Calculate the luminosity of a star from its flux and distance using L = 4 pi d^2 F.
Calcolatore Flusso Stellare
Calculate the observed flux from a star of known luminosity at a given distance: F = L / (4 pi d^2).
Calcolatore Luminosita Inverso del Quadrato
Compare the brightness of an object at two different distances using the inverse square law: F2/F1 = (d1/d2)^2.
Calcolatore Scala delle Distanze Cosmiche
Enter a distance in parsecs and see which measurement methods are appropriate at that scale, plus conversions to multiple units.
Calcolatore Luminosita Stellare
Calculate a star's luminosity from its absolute magnitude: L/L_sun = 10^((M_sun - M_star) / 2.5).
Stimatore Hertzsprung-Russell
Estimate a main-sequence star's luminosity and radius from its effective temperature using empirical scaling relations.
Calcolatore Durata Sequenza Principale
Estimate how long a star spends on the main sequence: t = t_sun * (M/M_sun) / (L/L_sun), approximated as t ≈ 10^10 * (M/M_sun)^(-2.5) years.
Calcolatore Raggio di Schwarzschild
Calculate the Schwarzschild radius (event horizon) of a black hole: r_s = 2 G M / c^2.
Calcolatore Limite di Chandrasekhar
Compute the Chandrasekhar mass limit for a white dwarf with a given mean molecular weight per electron: M_Ch = 5.83 / mu_e^2 solar masses.
Calcolatore Densita Stella di Neutroni
Estimate the average density of a neutron star from its mass and radius: rho = 3M / (4 pi r^3).
Calcolatore Raggio Nana Bianca
Estimate the radius of a white dwarf using the mass-radius relation: R/R_sun ~ 0.0126 * (M/M_sun)^(-1/3) for non-relativistic degeneracy.
Calcolatore Temperatura Stellare
Estimate a star's surface temperature from its B-V colour index using the Ballesteros formula: T = 4600 * (1/(0.92*(B-V)+1.7) + 1/(0.92*(B-V)+0.62)).
Calcolatore Lunghezza d'Onda di Picco di Wien
Find the peak emission wavelength of a blackbody from its temperature using Wien's displacement law: lambda_max = b / T.
Calcolatore Luminosita Stefan-Boltzmann
Calculate a star's luminosity from its radius and surface temperature: L = 4 pi R^2 sigma T^4.
Calcolatore Luminosita di Eddington
Compute the Eddington luminosity, the maximum luminosity a body can achieve when radiation pressure balances gravity: L_Edd = 4 pi G M c / kappa.
Calcolatore Relazione Massa-Luminosita
Estimate a main-sequence star's luminosity from its mass using the empirical relation L/L_sun ~ (M/M_sun)^3.5.
Stimatore Classe Spettrale
Estimate which spectral class (O, B, A, F, G, K, M) a star belongs to based on its effective temperature.
Calcolatore Colore-Temperatura Stellare
Convert between a star's colour temperature in Kelvin and its peak emission wavelength, plus approximate visible colour description.
Calcolatore Energia Fusione Nucleare
Calculate the energy released by converting a given mass of hydrogen to helium via stellar fusion (0.7% mass-energy conversion): E = 0.007 m c^2.
Calcolatore Gravita Planetaria
Calculate the surface gravity of a planet relative to Earth from its mass and radius ratios: g = g_Earth * (M/M_Earth) / (R/R_Earth)^2.
Calcolatore Peso sui Pianeti
Find what you would weigh on another planet by scaling your Earth weight by the surface gravity ratio.
Calcolatore Mezzogiorno Solare
Estimate the local solar noon time from your longitude and the standard meridian of your time zone.
Calcolatore Durata del Giorno
Estimate the number of daylight hours from your latitude and the Sun's declination using the hour-angle formula.
Calcolatore Fase Lunare
Estimate the Moon's illumination fraction and phase from the number of days since the last known new moon.
Calcolatore Ingrandimento Telescopio
Calculate the magnification of a telescope from the focal lengths of the objective and eyepiece: M = f_obj / f_eye.
Calcolatore Risoluzione Telescopio
Compute the angular resolution (Dawes limit) of a telescope from its aperture: theta = 116 / D (arcseconds, D in mm).
Calcolatore Rapporto Focale Telescopio
Calculate the focal ratio (f-number) of a telescope: f/# = focal_length / aperture.
Calcolatore Campo Visivo
Calculate the true field of view of a telescope and eyepiece combination: TFOV = AFOV / Magnification.
Calcolatore Magnitudine Limite
Estimate the faintest star visible through a telescope: m_lim = 2 + 5 log10(D) where D is aperture in mm.
Calcolatore Raccolta Luce Telescopio
Compare the light-gathering power of a telescope to the naked eye: LGP = (D / d_eye)^2.
Calcolatore Pupilla di Uscita Binocolo
Calculate the exit pupil of binoculars or a telescope eyepiece: exit_pupil = aperture / magnification.
Calcolatore Regola Esposizione Fotocamera
Calculate the maximum untracked exposure time before stars trail using the NPF rule or simplified 500 rule: t = 500 / (focal_length).
Calcolatore Energia Impatto Asteroide
Estimate the kinetic energy of an asteroid impact from its diameter, density, and velocity: KE = 0.5 * (pi/6) * d^3 * rho * v^2.
Calcolatore Equazione di Drake
Estimate the number of detectable civilisations in the Milky Way using the Drake equation: N = R* * fp * ne * fl * fi * fc * L.
Calcolatore Tasso Espansione Cosmica
Estimate the recession velocity of a distant galaxy from the Hubble-Lemaitre law v = H0 * d, where H0 is the Hubble constant.
Calcolatore Densita Energia Oscura
Compute the dark-energy density of the universe from the cosmological constant and the speed of light using rho_Lambda = Lambda * c^2 / (8 * pi * G).
Calcolatore Parametro Densita Materia
Calculate the matter density parameter Omega_m = rho_m / rho_crit, indicating what fraction of the critical density is made up of matter.
Calcolatore Densita Critica
Compute the critical density of the universe rho_crit = 3 H0^2 / (8 pi G), the density needed for a flat geometry.
Calcolatore Parametro di Decelerazione
Estimate the deceleration parameter q0 = Omega_m / 2 - Omega_Lambda, which indicates whether the expansion of the universe is accelerating or decelerating.
Calcolatore Distanza Comovente
Approximate the comoving distance to a galaxy at low redshift using d = c * z / H0, the linearised Hubble relation.
Calcolatore Distanza Propria
Convert comoving distance to the physical (proper) distance at a given epoch using d_proper = a(t) * d_comoving, where a is the scale factor.
Calcolatore Eta Cosmica
Estimate the age of the universe as t ≈ 1 / H0 (the Hubble time), providing a rough upper bound for a matter-only universe.
Calcolatore Densita Barionica
Compute the baryon (ordinary matter) density parameter Omega_b from the baryon density and the critical density.
Calcolatore Tempo di Hubble
Calculate the Hubble time t_H = 1/H0, the characteristic timescale of cosmic expansion, in seconds and gigayears.
Calcolatore Periodo Orbitale Planetario
Find the orbital period of a planet using Kepler's third law in a simplified form: T = sqrt(a^3) years, where a is the semi-major axis in AU.
Calcolatore Temperatura Superficie Planetaria
Estimate the effective surface temperature of a planet using Stefan-Boltzmann balance: T = ((L * (1 - A)) / (16 * pi * sigma * d^2))^0.25.
Calcolatore Altezza di Scala Atmosferica
Calculate the atmospheric scale height H = k_B * T / (m * g), the altitude over which pressure drops by a factor of e.
Calcolatore Forza di Marea
Compute the differential tidal acceleration across an object of size dr due to a mass M at distance d: a_tidal = 2 G M dr / d^3.
Calcolatore Albedo Planetario
Determine a planet's bond albedo from the reflected and incident flux: A = F_reflected / F_incident.
Calcolatore Temperatura di Equilibrio Planetario
Compute the radiative equilibrium temperature of a planet from stellar properties and albedo: T_eq = T_star * sqrt(R_star / (2 * d)) * pow(1 - A, 0.25).
Calcolatore Intensita Campo Magnetico Planetario
Estimate a planet's dipole magnetic field strength at the surface using the dipole approximation B = (mu0 / 4pi) * M_dipole / R^3.
Calcolatore Pressione Atmosferica in Quota
Calculate the atmospheric pressure at a given altitude using the barometric formula P = P0 * exp(-h / H), where H is the scale height.
Calcolatore Densita Planetaria
Calculate the mean bulk density of a planet from its mass and radius: rho = 3 M / (4 pi R^3).
Calcolatore Velocita di Fuga Planetaria
Compute the escape velocity from a planet's surface using v_esc = sqrt(2 G M / R).
Calcolatore FOV Sensore Fotocamera
Calculate the field of view of a camera sensor attached to a telescope: FOV = 2 * atan(sensor_size / (2 * focal_length)) converted to degrees.
Calcolatore Scala Pixel
Determine the angular size each pixel subtends on the sky: pixel_scale = 206.265 * pixel_size / focal_length arcseconds per pixel.
Calcolatore Risoluzione Immagine
Calculate the angular resolution of a telescope from its aperture using the Dawes limit: theta = 116 / D arcseconds, where D is in mm.
Calcolatore Tempo Esposizione Stelle
Calculate the maximum exposure time before stars trail using the NPF rule: t = (35 * N + 30 * p) / (f * cos(dec)), with declination correction.
Calcolatore Segnale-Rumore Stacking
Estimate the signal-to-noise improvement from stacking multiple exposures: SNR_total = SNR_single * sqrt(n).
Calcolatore Impatto Inquinamento Luminoso
Estimate how light pollution reduces contrast by computing the sky-brightness ratio: contrast_loss = sky_brightness / (sky_brightness + object_brightness).
Calcolatore Effetto Riduttore Focale
Calculate the effective focal length and f-ratio after adding a focal reducer: f_eff = f * reduction_factor, N_eff = N * reduction_factor.
Calcolatore Ingrandimento Barlow
Calculate the effective focal length and f-ratio after adding a Barlow lens: f_eff = f * barlow_factor.
Calcolatore Efficienza Quantica CCD
Calculate the number of photoelectrons generated by a CCD sensor: electrons = photon_flux * area * QE * exposure_time.
Calcolatore Tolleranza Errore di Inseguimento
Determine the maximum acceptable periodic error of a mount: PE_max = pixel_scale * acceptable_drift_px, in arcseconds.
Calcolatore Delta-V Razzo
Calculate the total delta-v a rocket can achieve from the Tsiolkovsky equation: dv = ve * ln(m0 / mf).
Calcolatore Equazione di Tsiolkovsky
Compute the required mass ratio for a given delta-v and exhaust velocity: m0/mf = exp(dv / ve).
Calcolatore Impulso Specifico
Calculate the specific impulse of a rocket engine: Isp = ve / g0, the exhaust velocity normalised by standard gravity.
Calcolatore Rapporto Spinta-Peso
Calculate the thrust-to-weight ratio of a rocket: TWR = thrust / (mass * g), determining if it can lift off.
Calcolatore Costo Manovra Orbitale
Calculate the delta-v for a Hohmann transfer between two circular orbits: dv = sqrt(GM/r1) * (sqrt(2r2/(r1+r2)) - 1) + sqrt(GM/r2) * (1 - sqrt(2r1/(r1+r2))).
Calcolatore Velocita Assistita dalla Gravita
Estimate the maximum speed change from a gravity assist: dv_max = 2 * v_planet * sin(theta/2), where theta is the bending angle.
Calcolatore Riscaldamento al Rientro
Estimate the stagnation-point heat flux during atmospheric reentry using q = k * sqrt(rho / r_nose) * v^3, the Sutton-Graves correlation.
Calcolatore Accelerazione Vela Solare
Calculate the acceleration of a solar sail from radiation pressure: a = 2 * S * A_sail / (c * m * d^2), where S is solar flux at 1 AU.
Calcolatore Massa Carburante Missione
Calculate the fuel mass required for a mission: m_fuel = m_dry * (exp(dv / ve) - 1).
Calcolatore Tempo Viaggio Interstellare
Estimate the travel time to a star at constant velocity: t = d / v, where d is the distance in light-years.