V424 Lacertae

{{Short description|Star in the constellation Lacerta}}

{{Starbox begin

| name = V424 Lacertae

}}

{{Starbox image

| image=

{{Location mark

|image=Lacerta constellation map.svg|alt=|float=center|width=240

|label=|position=right

|mark=Red circle.svg|mark_width=8|mark_link=V424 Lac

|x=325|y=567

}}

|caption=Location of V424 Lacertae (circled)

}}

{{Starbox observe

| epoch = J2000.0

| constell = Lacerta

| ra = {{RA|22|56|25.99839}}{{Cite DR3|1985889115564260224}}

| dec = {{DEC|+49|44|00.7587}}

| appmag_v = +4.94

}}

{{Starbox character

| class = K5 Ib{{cite journal|bibcode=1989ApJS...71..245K|title=The Perkins catalog of revised MK types for the cooler stars|journal=Astrophysical Journal Supplement Series|volume=71|pages=245|last1=Keenan|first1=Philip C.|last2=McNeil|first2=Raymond C.|year=1989|doi=10.1086/191373|s2cid=123149047 }}

| b-v = +1.77{{cite journal|bibcode=2002yCat.2237....0D|title=VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system|journal=CDS/ADC Collection of Electronic Catalogues|volume=2237|pages=0|last1=Ducati|first1=J. R.|year=2002}}

| u-b = +1.95

| variable=Lc{{cite journal|bibcode=2009yCat....102025S|title=VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)|journal=VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S|volume=1|display-authors=etal|last1=Samus|first1=N. N.|last2=Durlevich|first2=O. V.|year=2009}}

}}

{{Starbox astrometry

| radial_v = −9.50{{cite journal|bibcode=2006AstL...32..759G|title=Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system|journal=Astronomy Letters|volume=32|issue=11|pages=759–771|last1=Gontcharov|first1=G. A.|year=2006|doi=10.1134/S1063773706110065|arxiv = 1606.08053 |s2cid=119231169}}

| prop_mo_ra = {{val|-0.649}}

| prop_mo_dec = {{val|-2.768}}

| pm_footnote =

| parallax = 1.4018

| p_error = 0.1129

| parallax_footnote =

| absmag_v = −4.27{{cite journal|bibcode=2005ApJ...628..973L|arxiv=astro-ph/0504337|title=The Effective Temperature Scale of Galactic Red Supergiants: Cool, but Not As Cool As We Thought|journal=The Astrophysical Journal|volume=628|issue=2|pages=973–985|author1-link=Emily Levesque|last1=Levesque|first1=Emily M.|last2=Massey|first2=Philip|last3=Olsen|first3=K. A. G.|last4=Plez|first4=Bertrand|last5=Josselin|first5=Eric|last6=Maeder|first6=Andre|last7=Meynet|first7=Georges|year=2005|doi=10.1086/430901|s2cid=15109583}}

}}

{{Starbox detail

| mass = 6.8

| radius = {{val|288|26|21|fmt=commas}}{{Cite web|url=https://www.chara.gsu.edu/files/2023Meeting/Norris_NMT_Students_2023.pdf|publisher=CHARA|title=Student Science at NMT: Learning Optical Interferometry Through Projects on Evolved Stars|author=Ryan Norris}}

| luminosity = {{val|16600|4300|3400|fmt=commas}}{{Cite journal |last1=Taniguchi |first1=Daisuke |last2=Matsunaga |first2=Noriyuki |last3=Jian |first3=Mingjie |last4=Kobayashi |first4=Naoto |last5=Fukue |first5=Kei |last6=Hamano |first6=Satoshi |last7=Ikeda |first7=Yuji |last8=Kawakita |first8=Hideyo |last9=Kondo |first9=Sohei |last10=Otsubo |first10=Shogo |last11=Sameshima |first11=Hiroaki |last12=Takenaka |first12=Keiichi |last13=Yasui |first13=Chikako |date=2022-05-01 |title=Erratum: Effective temperatures of red supergiants estimated from line-depth ratios of iron lines in the YJ bands, 0.97-1.32 μm |bibcode=2022MNRAS.512.2669T |journal=Monthly Notices of the Royal Astronomical Society |volume=512 |issue=2 |pages=2669–2670 |doi=10.1093/mnras/stac686 |doi-access=free |issn=0035-8711}}

| temperature = {{val|3749|49}}

| metallicity_fe =

| gravity = +0.50{{cite journal|bibcode=2014A&A...566A.124L|arxiv=1405.5955|title=Low-amplitude and long-period radial velocity variations in giants HD 3574, 63 Cygni, and HD 216946|journal=Astronomy & Astrophysics|volume=566|pages=A124|last1=Lee|first1=B.-C.|last2=Han|first2=I.|last3=Park|first3=M.-G.|last4=Hatzes|first4=A. P.|last5=Kim|first5=K.-M.|year=2014|doi=10.1051/0004-6361/201321863|s2cid=54177778}}

| rotational_velocity =

| age =

}}

{{Starbox catalog

| names = Tengshe, V424 Lac, BD+48°3887, HR 8726, HD 216946, BD+48°3887, HIP 113288, SAO 52516

}}

{{Starbox reference

| Simbad = V424+Lac

}}

{{Starbox end}}

V424 Lacertae (V424 Lac), also named Tengshe, is a red supergiant and a variable star in the constellation Lacerta. It is a member of the Lacerta OB1 stellar association.

File:V424LacLightCurve.png light curve light curve for V424 Lacertae, adapted from Messina (2007)]]

The MK spectral type of V424 Lac has been determined to be K5, but it has also been classified as M0. It was discovered to be slightly variable using analysis of Hipparcos photometry. The total range is less than a tenth of a magnitude.{{cite journal|bibcode=1999IBVS.4659....1K|title=The 74th Special Name-list of Variable Stars|journal=Information Bulletin on Variable Stars|volume=4659|pages=1|last1=Kazarovets|first1=E. V.|last2=Samus|first2=N. N.|last3=Durlevich|first3=O. V.|last4=Frolov|first4=M. S.|last5=Antipin|first5=S. V.|last6=Kireeva|first6=N. N.|last7=Pastukhova|first7=E. N.|year=1999}} Multiple short periods are detected, as well as slow variations with a period of 1,100 or 1,601 days. Although listed in the General Catalogue of Variable Stars as a slow irregular variable, it has been considered to be either a semiregular variable or long secondary period variable.{{cite journal|bibcode=2007NewA...12..556M|title=Evidence for the pulsational origin of the Long Secondary Periods: The red supergiant star V424 Lac (HD 216946)|journal=New Astronomy|volume=12|issue=7|pages=556–561|last1=Messina|first1=Sergio|year=2007|doi=10.1016/j.newast.2007.04.002}}

There is an ultraviolet excess from V424 Lacertae, that may be due to an unseen companion, which could also explain the long secondary period. On this assumption, a low-mass stellar companion in a 1,382 day 6.2 AU orbit has been suggested.

This star was part of the ancient Chinese constellation Tengshe (螣蛇, Flying Serpent), dating back to the 2nd century BCE. The IAU Working Group on Star Names approved the name Tengshe for this star on 19 September 2024 and it is now so entered in the IAU Catalog of Star Names.{{cite web |title=IAU Catalog of Star Names |url=https://exopla.net/star-names/modern-iau-star-names/ |access-date=22 February 2025}}