J/A+A/693/A98ivo://CDS.VizieR/J/A+A/693/A98doi:10.26093/cds/vizier.36930098CDSde la Reza R.2025-03-03T20:01:54Z2025-01-07T09:14:36ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frgiant-starspeculiar-variable-starsinfrared-photometryThe existence of one percent of lithium-rich giant stars among normal, lithium-poor giant stars continues to be poorly explained. By merging two catalogues - one containing 10535 lithium-rich giant stars with lithium abundances ranging from 1.5 to 4.9dex, and the other detecting infrared sources - we have found 421 clump giant stars and 196 first-ascending giant stars with infrared excesses indicating stellar mass losses. The clump stars are the most lithium-rich. Approximately 5.8 percent of these stars appear to episodically lose mass in periods of approximately 10^4^ years or less, while the remaining stars have ceased their mass loss and have maintained their lithium for nearly 10^7^ years. We propose a scenario in which all giant stars with masses below two solar masses undergo prompt lithium enrichment with mass ejection episodes. We suggest that the mass loss results from internal angular momentum transport. It is possible that a transitory instability, perhaps of magnetic origin, rapidly transports the nuclear material responsible for the lithium enrichment to the stellar surface and triggers shell ejections. Additionally, the strong mass loss in some lithium-rich stars during their evolution activates their chromospheres, as observed in ultraviolet spectra. Furthermore, intense episodical mass losses in these stages lead to the observable formation of complex organic and inorganic particles, as detected in near-infrared spectra. In contrast to first-ascending giant stars, helium flashes during the clump can contribute to additional lithium enrichment alongside the aforementioned process. The combination of these two lithium sources may explain the much higher observed lithium abundances in clump stars as well as their observed infrared excesses. If our scenario, based on a universal and rapid lithium enrichment episode process, is correct, it could explain the rarity of lithium-rich giant stars.2025A&A...693A..98Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/693/A98CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toV/156 : LAMOST DR7 catalogs (Luo+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/693/A98https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/693/A98http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/693/A98https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/693/A98https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/693/A98http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/693/A98GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/693/A98/table1 (Stellar parameters of RC and RGB giant stars presenting IR excesses)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/693/A98/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/693/A98/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/693/A98/table1?GETtext/xml+votable180.050000true0.28733337.49247220.0055555555555555566/3 324 365 452 636 758 880 951 977 1051-1052 1101 1107 1125 1155 1161 1176 1180 1204 1209 1214 1222 1226 1238 1244 1246 1253 1257 1266 1278-1279 1283 1286 1294 1298 1300 1305-1306 1309-1310 1328 1340 1344-1345 1349 1354 1364 1374-1375 1377 1391 1394-1395 1420 1431 1443 1457 1461 1477 1488 1494 1542 1556 1558 1562 1569 1578 1587 1593 1595 1613 1621 1626 1630 1636-1637 1648 1658 1680 1719 1736 1753 1756 1782 1792-1793 1801-1802 1811 1837 1855 1860 1864 1867 1870 1876 1881 1910 1927 1935 1939 1969 1987 1990 1992-1993 1996 2018 2052 2186 2241 2354 2413 2456 2482 2489 2501 2503 2520 2568 2577 2610 2635 2650 2672 2812 2849 2873 2909-2912 2914 2917 2919 2931 2942 2988 2998 3000 3019 3083 3087 3092 3104 3109 3118 3122 3131 3133 3143 3146 3148 3154 3171 3176 3186 3199 3217 3227 3265 3329 3331 3336 3586 4137 4233 4482 4622 4643 4665 4691 4783 4823 4903 5178 5198 5542 5717 5738 5770 5823 6034 6176 6187 6193 6219 6274 6290 6300 6312-6313 6342 6344 6392 6400 6445 6467 6519 6585 6610 6670 6689 6693 6737 6740 6743 6754 6780 6806 6896 6929 6938 6997 7030 7057 7062 7076 7103 7139 7289 8265 8275 8470 8481 8535 8642 8856 8897 9050 9073 9130 9206 9762 9988 10059 10098 10106 10145 10440 10731 11523 11525 12401 12533 12577 12709 12778 13289 13292 13330 13378 13538 13577 13761 13785 13799 13814 13859 13861 13866 13877 13882 13897 13900-13901 13952 13955 13969-13971 13973-13974 13980 14006 14016 14061 14072 14102-14103 14170 14196 14226 14236 14284 14304 14411 14422 14431 14434 14468 14471 14516 14591 14636-14638 14642 14645 14670 14693 14701 14703-14704 14714 14726 14751 14754 14760 14763 14767 14770-14771 14773 14792 14794-14796 14803 14819 14824 14833 14928 14936 14973 14975 15059 15079 15088 15114 15122 15133 15141 15170-15171 15275 18009 18093 18118 18348 18887 18912 19039 19143 19150 19159 19170 19516 19780 19896 20278 20349 20419 21445 21458 21469 21488 21629 21733 21754 21764 21819 21836 21838 21895 21922 21925 21928 21996 22010 22040 22061 22064 22074 22087 22093 22108 22116 22121 22137 22147 22149 22153 22186 22196 22203 22205 22207 22209 22222 22235 22237 22239-22240 22247-22248 22254 22256 22259 22261 22298 22309 22348 22365 22409-22410 22417 22419 22431 22454 22480 22487 22494 22750 22811 22837 22867 22877 22898 22903 23004 23007 23300 23364 23418 23441 23445-23446 23494 23529 23548 23560 23584-23585 23602 23652 23654 23663 23673-23674 23677-23678 23690 23694 23708 23712 23716 23721 23759 23764 23813 23816 23822 23830 23833 23867 23888 23902-23903 23915 23925-23926 23933 23941 23947 23954 23958 23960 23966 23972 23980 23993 23995 23997-23999 24001 24005-24006 24013-24015 24045 24052-24053 24060 24062 24068 24070 24077 24084-24085 24117 24129 24135 24153 24164 24169 24172 24202 24206 24255 24269 24285 24307 24335-24337 24344 24348 24356 24368 24382 24386 24391-24392 24399 24426 24444 24452 24467-24468 24471 24480 24482 24494 24503 24525 24530-24531 24534 24544 24546 24551 24557 24563 24567 24575 26021 26905 27015 27192 27221 27285 27387 30632 30677 31037 31083 31104-31105 31209 31292 31393 31432 31435 31571 31614 31733 31744 31793 31840 31858 31872 31900 31967 32032 32136 32325 32360 32372 32412 32452 32466 32507 32570 32655 32695 32714https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/693/A98?format=asciiInfrareddefaultJ/A+A/693/A98/table1Stellar parameters of RC and RGB giant stars presenting IR excessesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameLAMOST identification (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainTeffEffective temperatureKphys.temperature.effectiveintlogglogarithm of surface gravitylog(cm.s**-2)phys.gravityfloat[Fe/H]Metallicitylog(Sun)phys.abund.ZfloatA(Li)Lithium Abundancephys.abundfloatIRIR excessphot.flux;arith.ratiofloatCCflagWISE confusion flag (1)meta.codecharPhqWISE photometric flag (2)meta.code.qualcharNote[1/3] IR sources (3)meta.noteintStageEvolutionary stage (4)meta.code.classchar