Guru Ast (Guru Moudhya) / Jupiter Combustion

When Jupiter (Guru) comes very close to the Sun, it disappears from the sky, and in astrology its auspicious influence/brightness is believed to temporarily weaken — this is called Ast, Moudhya, or Moudhyami (combustion). Guru Ast is considered to occur when the Sun-Jupiter angular separation comes within roughly 11°. In 2026, this period broadly falls between mid-July and mid-August — the exact start/end date varies by 2-3 days depending on the source's method (details below). This year, Jupiter is combust while in Cancer, its own sign of exaltation. During this period, auspicious ceremonies such as marriage, house-warming, mundan (tonsure), and upanayan (thread ceremony) are traditionally avoided.

Four distinct concepts can get confused because of the word "Guru" or nearby context — the difference, made explicit: 1. Guru Ast / Guru Moudhya (this page) — the period when Jupiter comes very close to the Sun (~within 11°) and disappears/dims in the sky. 2. Guru Vakri (Retrograde) — the apparent backward motion in Jupiter's visible path — a completely different calculation, not directly related to combustion. In 2026, the retrograde period (11 Nov 2025-11 Mar 2026, and 13 Dec 2026-13 Apr 2027) and the combustion period (July-August) fall at different times. 3. Guru Gochar/rashi transit — the broader, year-long concept of which zodiac sign Jupiter is in. Jupiter enters Cancer on 2 June 2026 and stays there until 31 October — Guru Ast is a small sub-period within this 5-month stay in Cancer. 4. Guru = teacher/Guru Purnima — this is merely a shared word, with no connection. The "Guru" in "Guru Ast" means the planet Jupiter, not a teacher or spiritual guru.

Unlike the panchang's daily vaar (weekday) and yog, which change day to day, Guru Ast is based on a planet's week-spanning position. Venus has its own, separate combustion period too — see Shukra Ast.

Significance

In muhurta-shastra, Jupiter is regarded as an auspicious karaka planet — governing marriage, progeny, knowledge, and prosperity. Once combust, its "capacity to bless" is believed to temporarily weaken, so auspicious ceremonies dependent on it (especially marriage) are avoided during this period.

A combust planet doesn't become "ineffective" — the general understanding is that its results are only dimmed, delayed, or received in a subtler/private form.

Because Jupiter's apparent motion around the Sun is slow, its combustion period occurs roughly once a year, lasting about 25-35 days.

There's a loose connection to Kharmas, but don't confuse the two — Kharmas is the period when the Sun is in Jupiter's sign (Sagittarius/Pisces); Guru Ast is the period when Jupiter itself is close to the Sun. Both are thematically related as "Jupiter-linked muhurat pauses," but the astronomical reason is entirely different — both can occur at different times within the same year, and shouldn't be assumed to overlap.

How Guru Ast is determined (the concept)

By traditional criteria, each planet has a specific angular distance (in degrees) from the Sun within which it is considered "combust":

It's notable that Jupiter's 11° figure stays the same whether direct or retrograde — unlike other planets, the degree doesn't shrink during retrograde motion.

There can be a difference of a few days between the classical calculation using a pure 11° angular separation and modern panchang software's visibility-based algorithm — this shows up in the 2026 dates below. Calculating with the same method for different cities (e.g. Mumbai vs. Vijayawada) produces only a difference of minutes, not days — meaning the real reason for the date difference is the method, not the location.

Who this applies to

This isn't a personal vrat — anyone making a muhurat decision (especially those planning marriage, house-warming, or a new beginning) considers this. It's also useful for the general astrology/panchang reader as an explanation of "why auspicious muhurats aren't available right now."

What to avoid

Ceremonies traditionally avoided:

• Marriage/engagement
• Upanayan (thread ceremony)
• Griha pravesh (house-warming)
• Murti-pratishtha (idol consecration), starting new construction

Some sources also include naming-ceremony-type rituals in this list, while one source separately marks naming ceremonies as "permitted" — this is an inconsistency across sources, so the final decision should follow local priest/tradition.

As a soft recommendation (not a strict prohibition), avoiding major financial decisions, starting a new business, or making large investments is advised — but this is presented as "caution," not "forbidden." Routine transactions and medical treatment, however, are considered fine to continue during this period.

Remedies (general worship)

Traditionally observed remedies — worshipping Vishnu/Brihaspati on Thursdays, donating yellow items (turmeric, chana dal), and chanting Guru mantras.

Good to know

• This Cancer-sign combustion is specific to this year only — since Jupiter sits in a different sign each year, both the sign and the exact dates of the next combustion period will differ; check that year's panchang when the time comes.

Date (occurrences, 2026)

The panchang carries loose astronomical notes ("Guru Lop"/"Guru Darshan") around these dates, but doesn't track Guru Ast as a dedicated concept with a confirmed date-range — and external sources disagree with each other on the exact date too:

Jupiter remains in Cancer throughout this entire combustion period (Jupiter is in Cancer for its 5-month transit from 2 June to 31 October 2026; the combustion is a sub-period within that) — this is consistent across all sources.

For the exact day/time, check a direct panchang tool for that day (selecting your own city) — this page only gives the general window and concept.

FAQ

What is Guru Ast?

The period when Jupiter comes very close to the Sun (within ~11°) and disappears/dims in the sky — also called Moudhya/Moudhyami.

When is Guru Ast in 2026?

Broadly mid-July to mid-August 2026 (starting 14-17 July, ending 11-13 August depending on the source) — check a panchang tool for the exact date.

Why don't people marry during Guru Ast?

Jupiter is regarded as the karaka planet for marriage and auspicious ceremonies; once combust, its capacity to bless is traditionally believed to temporarily weaken — so marriage muhurats are avoided during this period.

Are Guru Ast and Guru Vakri (retrograde) the same?

No, they're two different concepts (combustion = proximity to the Sun; retrograde = apparent backward motion). In 2026 the two fall at different times.

What should be avoided during Guru Ast?

Marriage, upanayan, griha pravesh, murti-pratishtha, starting new construction — by tradition; also a soft recommendation to avoid major financial decisions.

When do auspicious muhurats resume after Guru Ast ends?

Gradually after combustion ends (2026: roughly between 11-13 August, depending on the source).

Is it significant that Jupiter becomes combust while in its exalted sign, Cancer?

It's certain that Cancer is Jupiter's own sign of exaltation; but the idea that "this makes the effect milder/special" is one interpretation, not presented here as settled astrological doctrine.

How many times a year does Guru Ast occur?

Roughly once, for about 25-35 days (due to Jupiter's slow motion).