A Activity diagram used in UML 6/9 and SysML B Bachman diagram Booch used in software engineering Block diagram Block Definition Diagram BDD used in SysML C Carroll diagram Cartogram Catalytic cycle Chemical equation Curly arrow diagram Category theory diagrams Cause-and-effect diagram Chord diagram Circuit diagram Class diagram from UML 1/9 Collaboration diagram from UML 2.0 Communication diagram from UML 2.0 Commutative diagram Comparison diagram Component diagram from UML 3/9 Composite structure diagram from UML 2.0 Concept map Constellation diagram Context diagram Control flow diagram Contour diagram Cordier diagram Cross functional flowchart D Data model diagram Data flow diagram Data structure diagram Dendrogram Dependency diagram Deployment diagram from UML 9/9 Dot and cross diagram Double bubble map used in education Drakon-chart E Entity-Relationship diagram ERD Event-driven process chain Euler diagram Eye diagram a diagram of a received telecommunications signal Express-G Extended Functional Flow Block Diagram EFFBD F Family tree Feynman diagram Flow chart Flow process chart Flow diagram Fusion diagram Free body diagram G Gantt chart shows the timing of tasks or activities used in project management Grotrian diagram Goodman diagram shows the fatigue data example: for a wind turbine blades H Hasse diagram HIPO diagram I Internal Block Diagram IBD used in SysML IDEF0 IDEF1 entity relations Interaction overview diagram from UML Ishikawa diagram J Jackson diagram K Karnaugh map Kinematic diagram L Ladder diagram Line of balance Link grammar diagram M Martin ERD Message Sequence Chart Mind map used for learning, brainstorming, memory, visual thinking and problem solving Minkowski spacetime diagram Molecular orbital diagram N N2 Nassi Shneiderman diagram or structogram a representation for structured programming Nomogram Network diagram O Object diagram from UML 2/9 Organigram Onion diagram also known as "stacked Venn diagram" P Package diagram from UML 4/9 and SysML Parametric diagram from SysML PERT Petri net shows the structure of a distributed system as a directed bipartite graph with annotations Phylogenetic tree - represents a phylogeny evolutionary relationships among groups of organisms Piping and instrumentation diagram P&ID Phase diagram used to present solid/liquid/gas information Plant Diagram Pressure volume diagram used to analyse engines Pourbaix diagram Process flow diagram or PFD used in chemical engineering Program structure diagram R Radar chart Radial Diagram Requirement Diagram Used in SysML Rich Picture R-diagram Routing diagram S Sankey diagram represents material, energy or cost flows with quantity proportional arrows in a process network. Sentence diagram represents the grammatical structure of a natural language sentence. Sequence diagram from UML 8/9 and SysML SDL/GR diagram Specification and Description Language. SDL is a formal language used in computer science. Smith chart Spider chart Spray diagram SSADM Structured Systems Analysis and Design Methodology used in software engineering Star chart/Celestial sphere State diagram are used for state machines in software engineering from UML 7/9 Swim lane Syntax diagram used in software engineering to represent a context-free grammar Systems Biology Graphical Notation a graphical notation used in diagrams of biochemical and cellular processes studied in Systems biology System context diagram System structure Systematic layout planning T Timing Diagram: Digital Timing Diagram Timing Diagram: UML 2.0 TQM Diagram Treemap U UML diagram Unified Modeling Language used in software engineering Use case diagram from UML 5/9 and SysML V Value Stream Mapping Venn diagram Voronoi diagram W Warnier-Orr Williot diagram Y Yourdon-Coad see Edward Yourdon, used in software engineering
The Hertzsprung–Russell diagram, or H–R diagram, is a plot of stellar luminosity against surface temperature. Most stars lie on the main sequence, which extends diagonally across the H–R diagram from high temperature and high luminosity to low temperature and low luminosity.
L = 4πR 2 σT 4. where L is the luminosity, R is the stellar radius, and T is the temperature (alpha is a constant). From this we see that stars above the main sequence on the H R diagram (higher luminosity) , with the same temperature as cooler main sequence stars, have greater surface areas (larger radii).
There are also two bands of stars in the H R diagram that are brighter than Main Sequence stars with the same effective temperatures. The Luminosity Radius Temperature relation tells us that the stars in these bands must therefore be larger in radius than Main Sequence stars. There are two groups of giant stars: Giants
The Hertzsprung–Russell diagram, or H–R diagram, is a plot of stellar luminosity against surface temperature. Most stars lie on the main sequence, which extends diagonally across the H–R … 18.4: The H R Diagram Physics LibreTexts
Let's discuss some of the many features of the H R diagram that are displayed. The x axis of the plot represents the temperature of a star (please note that the temperatures go from high to low if we look from left to right on the axis). This temperature scale is in Kelvin,...
HR may mean Human Resources in other contexts but in astronomy it means the Hertzsprung Russell Diagram. The Hertzsprung Russell diagram (usually referred to by the abbreviation H R diagram or HRD, also known as a Colour Magnitude diagram, or CMD) shows the relationship between absolute magnitude, luminosity, classification, and surface temperature of stars.
Now convert the radius from units of m to units of solar radius: R in R⊙ = R in meters x 1 R⊙ 6.96 x 10 8 m R = 6.46 x 108 m x 1 R ⊙ 6.96 x 10 8 m R = 0.93 R⊙ ≈ 1 R⊙ . D. Calculating the Radii of the Stars Using the HR Diagram in Figure 1, estimate the luminosity and temperature of all the stars listed
The diagram below shows the possible axes for an H R diagram. The vertical axis displays the luminosity of the stars. This is either as a ratio compared with that of the Sun or as absolute magnitude, M .
For example, if a star has the same surface temperature as the sun and a radius that is twice as big, its luminosity must be L = (2 R)2(T)4 = 4L. One can experiment with the relationships between luminosity, temperature (spectral type), and radius with the Stellar Luminosity Calculator.
There are 3 main regions (or evolutionary stages) of the HR diagram: The main sequence stretching from the upper left (hot, luminous stars) to the bottom right (cool, faint stars) dominates the HR diagram. It is here that stars spend about 90% of their lives burning hydrogen into helium in their cores.