Planetary Combustion

Planetary combustion is a Vedic astrology concept where a planet loses its strength when it comes too close to the Sun. The ndastro_engine.combustion module provides functions to determine if a planet is in combustion and to find combustion periods.

What is Combustion?

In Vedic astrology, when a planet is too close to the Sun (within a certain degree range called the "orb"), it is said to be "combust" or "burnt." A combust planet is considered weakened and may not fully express its qualities.

Combustion Orbs

Different planets have different combustion orbs:

Planet	Combustion Orb
Mercury	12°
Venus	8°
Mars	17°
Jupiter	11°
Saturn	15°

Note

The Sun, Moon, Rahu, and Kethu cannot be in combustion.

Checking if a Planet is Combust

Use the is_planet_in_combust() function to check if a planet is combust on a specific date:

from datetime import datetime
import pytz
from ndastro_engine.combustion import is_planet_in_combust
from ndastro_engine.enums import Planets

# Check if Mercury is combust on a specific date
check_date = datetime(2026, 2, 13, 12, 0, 0, tzinfo=pytz.UTC)
latitude = 40.7128  # New York
longitude = -74.0060

is_combust, period_start, period_end = is_planet_in_combust(
    check_date=check_date,
    planet_name=Planets.MERCURY.astronomical_code,
    latitude=latitude,
    longitude=longitude
)

if is_combust:
    print(f"Mercury is combust on {check_date.date()}")
    print(f"Combustion period: {period_start.date()} to {period_end.date()}")
else:
    print(f"Mercury is not combust on {check_date.date()}")

The function returns a tuple containing: - is_combust (bool): Whether the planet is combust on the specified date - period_start (datetime | None): The start date of the combustion period, or None if not combust - period_end (datetime | None): The end date of the combustion period, or None if not combust

Finding Combustion Periods

To find all combustion periods for a planet within a date range, use the find_combust_periods() function:

from datetime import datetime
import pytz
from ndastro_engine.combustion import find_combust_periods
from ndastro_engine.enums import Planets

# Find all combustion periods for Venus in 2026
start_date = datetime(2026, 1, 1, tzinfo=pytz.UTC)
end_date = datetime(2026, 12, 31, tzinfo=pytz.UTC)
latitude = 19.0760  # Mumbai
longitude = 72.8777

combust_periods = find_combust_periods(
    start_date=start_date,
    end_date=end_date,
    planet_name=Planets.VENUS.astronomical_code,
    latitude=latitude,
    longitude=longitude
)

# Display the results
for period_start, period_end in combust_periods:
    duration = (period_end - period_start).days
    print(f"Venus combust from {period_start.date()} to {period_end.date()} ({duration} days)")

Checking Multiple Planets

You can check combustion status for multiple planets:

from datetime import datetime
import pytz
from ndastro_engine.combustion import is_planet_in_combust
from ndastro_engine.enums import Planets

check_date = datetime(2026, 3, 15, 12, 0, 0, tzinfo=pytz.UTC)
latitude = 51.5074  # London
longitude = -0.1278

# Check all planets that can be combust
planets = [
    Planets.MERCURY,
    Planets.VENUS,
    Planets.MARS,
    Planets.JUPITER,
    Planets.SATURN
]

print(f"Combustion status on {check_date.date()}:\n")
for planet in planets:
    is_combust, period_start, period_end = is_planet_in_combust(
        check_date=check_date,
        planet_name=planet.astronomical_code,
        latitude=latitude,
        longitude=longitude
    )
    if is_combust:
        print(f"{planet.name}: Combust (until {period_end.date()})")
    else:
        print(f"{planet.name}: Not combust")

Understanding the Results

Combustion Periods

The find_combust_periods() function returns a list of tuples, where each tuple contains: - period_start: The datetime when combustion begins - period_end: The datetime when combustion ends

Periods are returned in chronological order and do not overlap.

Location Impact

While planetary combustion is primarily based on the angular separation from the Sun (which doesn't vary significantly with observer location), there can be minor differences due to: - Parallax effects - Atmospheric refraction calculations

For most practical purposes, the location has minimal impact on combustion calculations.

Practical Examples

Example 1: Find When Mercury is Not Combust

from datetime import datetime, timedelta
import pytz
from ndastro_engine.combustion import find_combust_periods
from ndastro_engine.enums import Planets

# Get combustion periods for Mercury
start = datetime(2026, 6, 1, tzinfo=pytz.UTC)
end = datetime(2026, 9, 30, tzinfo=pytz.UTC)
lat, lon = 35.6762, 139.6503  # Tokyo

combust_periods = find_combust_periods(start, end, Planets.MERCURY.astronomical_code, lat, lon)

# Find non-combust periods
current = start
non_combust_periods = []

for period_start, period_end in combust_periods:
    if current < period_start:
        non_combust_periods.append((current, period_start))
    current = period_end

if current < end:
    non_combust_periods.append((current, end))

print("Mercury is NOT combust during:")
for nc_start, nc_end in non_combust_periods:
    days = (nc_end - nc_start).days
    print(f"  {nc_start.date()} to {nc_end.date()} ({days} days)")

Example 2: Count Combust Days in a Year

from datetime import datetime
import pytz
from ndastro_engine.combustion import find_combust_periods
from ndastro_engine.enums import Planets

start = datetime(2026, 1, 1, tzinfo=pytz.UTC)
end = datetime(2026, 12, 31, tzinfo=pytz.UTC)
lat, lon = 40.7128, -74.0060  # New York

planets = [
    ("Mercury", Planets.MERCURY.astronomical_code),
    ("Venus", Planets.VENUS.astronomical_code),
    ("Mars", Planets.MARS.astronomical_code),
    ("Jupiter", Planets.JUPITER.astronomical_code),
    ("Saturn", Planets.SATURN.astronomical_code)
]

print("Total combust days in 2026:\n")
for planet_name, planet_code in planets:
    periods = find_combust_periods(start, end, planet_code, lat, lon)
    total_days = sum((p_end - p_start).days for p_start, p_end in periods)
    print(f"{planet_name:8} : {total_days:3} days ({len(periods)} period(s))")

Example 3: Get Combustion Period Details

from datetime import datetime
import pytz
from ndastro_engine.combustion import is_planet_in_combust
from ndastro_engine.enums import Planets

check_date = datetime(2026, 3, 15, 12, 0, 0, tzinfo=pytz.UTC)
lat, lon = 40.7128, -74.0060  # New York

is_combust, period_start, period_end = is_planet_in_combust(
    check_date, Planets.SATURN.astronomical_code, lat, lon
)

if is_combust:
    duration = (period_end - check_date).days
    print(f"Saturn is combust on {check_date.date()}")
    print(f"Combustion started: {period_start.date()}")
    print(f"Combustion ends: {period_end.date()}")
    print(f"Days remaining in combustion: {duration}")
else:
    print(f"Saturn is not combust on {check_date.date()}")