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23-583: Small emission nebula IC 1871 is present just left of the top of the head, and small emission nebulae 670 and 669 are just below the lower back area. The galaxies Maffei 1 and Maffei 2 are both nearby the nebula, although light extinction from the Milky Way makes them very hard to see. Once thought to be part of the Local Group , they are now known to belong to their own group- the IC 342/Maffei Group . This complex

46-444: A distance of 3 Mpc this corresponds to approximately 23 kpc. The total visible absolute magnitude of Maffei 1, M V =−20.8, is comparable to that of the Milky Way. Maffei 1 possesses a tiny blue nucleus at its center approximately 1.2 pc across. It contains about 29 solar masses of ionized hydrogen. This implies that it has undergone recent star formation. There are no signs of an active galactic nucleus (AGN) in

69-531: A long time failed to identify any of them. Observations by the Hubble Space Telescope in 2000 revealed about 20 globular cluster candidates in the central region of the galaxy. Later infrared observations from telescopes on the ground also found a population of bright globular cluster candidates. Maffei 1 is a principal member of a nearby group of galaxies. The group's other members are the giant spiral galaxies IC 342 and Maffei 2 . Maffei 1 has also

92-460: A result, optical galaxy catalogues are usually incomplete close to the galactic plane. Many projects have attempted to bridge the gap in knowledge caused by the Zone of Avoidance. The dust and gas in the Milky Way cause extinction at optical wavelengths, and foreground stars can be confused with background galaxies. However, the effect of extinction drops at longer wavelengths, such as the infrared , and

115-463: A small satellite spiral galaxy, Dwingeloo 1 , as well as a number of dwarf satellites like MB1 . The IC 342/Maffei Group is one of the closest galaxy groups to the Milky Way galaxy. Zone of avoidance The Zone of Avoidance ( ZOA , ZoA ), or Zone of Galactic Obscuration ( ZGO ), is the area of the sky that is obscured by the Milky Way . The Zone of Avoidance was originally called

138-447: Is a core type elliptical. Both the boxy shape and the presence of an underluminous core are typical of intermediate to massive ellipticals. The apparent dimensions of Maffei 1 depend strongly on the wavelength of light because of the heavy obscuration by the Milky Way. In blue light it is 1–2′ across while in the near infrared its major axis reaches 23′—more than 3/4 of the Moon's diameter. At

161-412: Is a slightly flattened core type elliptical galaxy. It has a boxy shape and is made mainly of old metal-rich stars. It has a tiny blue nucleus in which stars continue to form. Like all large ellipticals it contains a significant population of globular clusters. Maffei 1 is situated at an estimated distance of 3–4 Mpc from the Milky Way. It may be the closest giant elliptical galaxy. Maffei 1 lies in

184-480: Is further hindered by the fact that it is covered by myriads of faint Milky Way stars, which can easily be confused with its own. As a result, determining its distance has been particularly difficult. In 1971, soon after its discovery, Hyron Spinrad estimated the distance to Maffei 1 at about 1 Mpc, which would place it within the Local Group of galaxies. In 1983 this estimate was revised up to 2.1 −0.8  Mpc by Ronald Buta and Marshall McCall using

207-419: Is the eastern neighbor of IC1805 ( Heart Nebula ) and the two are often mentioned together as the "Heart and Soul". W5, a radio source within the nebula, spans an area of sky equivalent to four full moons and is about 6,500 light-years away in the constellation Cassiopeia. Like other massive star-forming regions, such as Orion and Carina, W5 contains large cavities that were carved out by radiation and winds from

230-474: The Zone of Avoidance and is heavily obscured by the Milky Way's stars and dust . If it were not obscured, it would be one of the largest (about 3 ⁄ 4 the size of the full moon ), brightest, and best-known galaxies in the sky. It can be observed visually, using a 30–35 cm or bigger telescope under a very dark sky. The Italian astronomer Paolo Maffei was one of the pioneers of infrared astronomy . In

253-465: The Zone of Few Nebulae in an 1878 paper by English astronomer Richard Proctor that referred to the distribution of " nebulae " in John Herschel 's General Catalogue of Nebulae . When viewing space from Earth, the attenuation , interstellar dust and stars in the plane of the Milky Way (the galactic plane ) obstruct the view of around 20% of the extragalactic sky at visible wavelengths . As

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276-698: The 1950s and 60s, in order to obtain high quality images of celestial objects in the very near infrared part of the spectrum (the I-band, 680–880 nm), he used chemically hyper-sensitized standard Eastman emulsions I-N. To achieve the hyper-sensitization he immersed them in 5% ammonia solution for 3–5 minutes. This procedure increased their sensitivity by an order of magnitude. Between 1957 and 1967 Maffei observed many different objects using this technique, including globular clusters and planetary nebulae . Some of those objects were not visible at all on blue light (250–500 nm) sensitive plates. The galaxy Maffei 1

299-451: The Milky Way is effectively transparent at radio wavelengths. Surveys in the infrared, such as IRAS and 2MASS , have given a more complete picture of the extragalactic sky. Two very large nearby galaxies, Maffei 1 and Maffei 2 , were discovered in the Zone of Avoidance by Paolo Maffei by their infrared emission in 1968. Even so, approximately 10% of the sky remains difficult to survey as extragalactic objects can be confused with stars in

322-464: The Milky Way. Projects to survey the Zone of Avoidance at radio wavelengths, particularly using the 21 cm spin-flip emission line of neutral atomic hydrogen (known in astronomical parlance as H I line ), have detected many galaxies that could not be detected in the infrared. Examples of galaxies detected from their HI emission include Dwingeloo 1 and Dwingeloo 2 , discovered in 1994 and 1996, respectively. Recent astronomical studies revealed

345-512: The brightest asymptotic giant branch stars in Maffei 1 and concluded that it is located at the distance 4.4 −0.5  Mpc from the Sun . The latest determination of the distance to Maffei 1, which is based on the re-calibrated luminosity/velocity dispersion relation for the elliptical galaxies and the updated extinction, is 2.85 ± 0.36 Mpc , or over 9 million light years away. For perspective,

368-405: The center of Maffei 1. The X-ray emission from the center is extended and likely comes from a number of stellar sources. Maffei 1 is mainly made of old metal-rich stars more than 10 billion years in age. As a large elliptical galaxy, Maffei 1 is expected to host a significant population of globular clusters (about 1100). However, due to heavy intervening absorption, ground-based observations for

391-404: The center of the cavities. Maffei 1 Maffei 1 is a massive elliptical galaxy in the constellation Cassiopeia . Once believed to be a member of the Local Group of galaxies, it is now known to belong to a separate group, the IC 342/Maffei Group . It was named after Paolo Maffei , who discovered it and the neighboring Maffei 2 in 1967 via their infrared emissions. Maffei 1

414-517: The general expansion of the Universe . Maffei 1 is a massive elliptical galaxy classified as type E3 in the Hubble classification scheme. This means that it is slightly flattened, its semi-minor axis being 70% of its semi-major axis . Maffei 1 has also a boxy shape (E(b)3 type), while its central region (radius ≈ 34 pc) is deficient in light emission as compared to the r law, meaning that Maffei 1

437-492: The general relation between the luminosity and velocity dispersion for elliptical galaxies . That distance puts Maffei 1 well outside the Local Group, but close enough to have influenced it in the past. In 1993 Gerard Luppino and John Tonry used surface brightness fluctuations to derive a new distance estimate to Maffei 1 of 4.15 ± 0.5 Mpc . Later in 2001, Tim Davidge and Sidney van den Bergh used adaptive optics to observe

460-518: The nearby Andromeda Galaxy is estimated to be about 2.5 million light years away. The larger (≥3 Mpc) distances reported in the past 20 years would imply that Maffei 1 has never been close enough to the Local Group to significantly influence its dynamics. Maffei 1 moves away from the Sun at the speed of about 66 km/s. Its velocity relative to the Local Group's center of mass is, however, 297 km/s away. That means that Maffei 1 participates in

483-464: The region's most massive stars. According to the theory of triggered star formation , the carving out of these cavities pushes gas together, causing it to ignite into successive generations of new stars. The image in the gallery above contains some of the best evidence yet for the triggered star formation theory. Scientists analyzing the photo have been able to show that the ages of the stars become progressively and systematically younger with distance from

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506-523: Was discovered on a hyper-sensitized I-N photographic plate exposed on 29 September 1967 with the Schmidt telescope at Asiago Observatory . Maffei found Maffei 1, together with its companion spiral galaxy Maffei 2 , while searching for diffuse nebulae and T Tauri stars . The object had an apparent size up to 50″ in the near infrared but was not visible on the corresponding blue light sensitive plate. Its spectrum lacked any emission or absorption lines. Later it

529-495: Was shown to be radio-quiet as well. In 1970 Hyron Spinrad suggested that Maffei 1 is a nearby heavily obscured giant elliptical galaxy. Maffei 1 would be among the ten brightest galaxies in the northern sky if not situated behind the Milky Way. Maffei 1 is located only 0.55° from the galactic plane in the middle of the zone of avoidance and suffers from about 4.7 magnitudes of extinction (a factor of about 1/70) in visible light. In addition to extinction, observation of Maffei 1

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