Question: What Latvian deity ranks just below the solar goddess of Latvian mythology in popularity?

Context paragraphs:
Auseklis: Auseklis (derived from root "aus-" - "dawn") was a Latvian god, and the personification of the celestial body Venus.  He is the third most popular deity in Latvian mythology after Saulė and Mēness, but is almost exclusively mentioned in folk songs.

List of nature deities: In nature worship, a nature deity is a deity in charge of forces of nature such as water deity, vegetation deity, sky deity, solar deity, fire deity or any other naturally occurring phenomena such as death deity or fertility deity.  Accepted in panentheism, pantheism, deism, polytheism, animism, totemism, shamanism and paganism the deity embodies natural forces and can have characteristics of the mother goddess, Mother Nature or lord of the animals.

Miķelis: Miķelis is a Latvian male given name.  It is also Latvian name of archangel Michael, therefore the celebration of autumn equinox is called Miķeļi in Latvian and Miķelis is named as protector of horses and good harvest, likely taking over functions of Jumis, a fertility deity in Latvian mythology.

Historia Lettica: Historia Lettica is one of the oldest historical books about Latvia, Latvian mythology and Latvian language.  It was written by Lutheran priest Paul Einhorn in the German language and published in 1649.

Latvian mythology: Latvian mythology is set of paganic beliefs of Latvian people reconstructed from written evidence and folklore materials.

Centeotl: In Aztec mythology, Centeōtl ] (also known as Centeocihuatl or Cinteotl) is the maize deity.  "Cintli" ] means "dried maize still on the cob" and "teōtl" ] means "deity".  According to the Florentine Codex, Centeotl is the son of the earth goddess, Tlazolteotl and solar deity Piltzintecuhtli, the planet Mercury.  Born on the day-sign 1 Xochitl.  Another myth claims him as the son of the goddess Xochiquetzal.  The majority of evidence gathered on Centeotl suggests that he is usually portrayed as a young man (although a debate is still ongoing), with yellow body colouration.  Some specialists believe that Centeotl used to be the maize goddess Chicomecōātl.  Centeotl was considered one of the most important deities of the Aztec era.  There are many common features that are shown in depictions of Centeotl.  For example, there often seems to be maize in his headdress.  Another striking trait is the black line passing down his eyebrow, through his cheek and finishing at the bottom of his jaw line.  These face markings are similarly and frequently used in the late post-classic depictions of the 'foliated' Maya maize god.

Perkūnas: Perkūnas (Lithuanian: "Perkūnas" , Latvian: "Pērkons" or "Pērkon", Old Prussian: "Perkūns", Yotvingian: "Parkuns") was the common Baltic god of thunder, one of the most important deities in the Baltic pantheon.  In both Lithuanian and Latvian mythology, he is documented as the god of thunder, rain, mountains, oak trees and the sky.

Ūsiņš: Ūsiņš (] ) is a deity in Latvian mythology, the god of light and spring, symbol of fertility, guardian of horses and bees.

Saulė: Saulė (Lithuanian: "Saulė" , Latvian: "Saule" ) is a solar goddess, the common Baltic solar deity in the Lithuanian and Latvian mythologies.  The noun "Saulė"/"Saule" in the Lithuanian and Latvian languages is also the conventional name for the Sun and originates from the Proto-Baltic name *"Sauliā" > *"Saulē".

Māra: Māra is the highest-ranking goddess in Latvian mythology, Mother Earth, a feminine counterpart to Dievs (God).  She may be thought as the alternate side of Dievs (like in Yin and Yang).  Other Latvian goddesses, sometimes all of them, are considered her assistants, or alternate aspects.  Māra may have been also the same goddess as Lopu māte, Piena Māte (Mother of the Milk), Veļu Māte (mother of the souls/spirits), Zemes Māte (Mother of the Earth), and many other "mothers", like of Wood, Water, Sea, Wind.  Māra is also depicted in Latvian mythology as the goddess of good fortune.

Supporting paragraphs: Auseklis Saulė
Answer: Auseklis