Quote from smAsh on January 10, 2020, 8:34 am

Most massive object in the solar system- The Sun.

Most massive planet in the solar system- Jupiter.

Quote from smAsh on January 10, 2020, 10:19 am

Most awesome viewers of our videos- Patrons.

Seriously, though.

Here's another (I'm only doing these from memory so far):

Most intense steady x-ray source- Crab Pulsar. (image credit: CHANDRA)

We'll make this entire list graphical also, eventually.  Feel free to submit your favorite MOSTS, but keep in mind that they all get fact checked, including my own submissions.

Quote from smAsh on January 11, 2020, 10:19 am

Most massive object (known) in the Milky Way Galaxy:

Sagittarius A*, pronounced 'Sagittarius-A-star' is the most massive radio source known in the Milky Way.  The supermassive 'black hole' at the center of the galaxy is the source of much academic and theoretical debate.

More on this and the 'Galactic Current Sheet' later...

 

 

Quote from smAsh on January 11, 2020, 1:32 pm

THE CLOSEST STARS:

(simply copy/ pasted from wikipedia, pardon the goof ball formatting)

https://en.wikipedia.org/wiki/List_of_nearest_stars_and_brown_dwarfs

Known star systems within 5.0 parsecs (16.3 light-years)

Designation		Distance[6] (light-years (±err))	Stellar class	Apparent magnitude (mV[5] or mJ)	Absolute magnitude (MV[5] or MJ)	Epoch J2000.0		Parallax (mas (±err)) [5][note 1]	Discovery date [note 2]	Notes and additional references
System	Star					Right ascension[5]	Declination[5]
Solar System	Sun (Sol)	0.0000158	G2V[5]	−26.74	4.85	N/A	N/A	N/A	N/A	eight planets
Alpha Centauri (Rigil Kentaurus)	Proxima Centauri (V645 Centauri)	4.2441±0.0011	M5.5Ve	11.09	15.53	14h 29m 43.0s	−62° 40′ 46″	768.50±0.20[7]	1915	flare star, one planet (b) (2016), tentative evidence for second planet (c) (2019)[8]
	α Centauri A (HD 128620)	4.3650±0.0068	G2V[5]	0.01	4.38	14h 39m 36.5s	−60° 50′ 02″	747.23±1.17 [9][10][11]	N/A
	α Centauri B (HD 128621)		K1V[5]	1.34	5.71	14h 39m 35.1s	−60° 50′ 14″		1689	one suspected planet (c) (2013) (planet b refuted in 2015)
Barnard's Star (BD+04°3561a)		5.9577±0.0032	M4.0Ve	9.53	13.22	17h 57m 48.5s	+04° 41′ 36″	547.45±0.29[7]	1916	flare star, largest-known proper motion,[12] one known planet (b)[13]
Luhman 16 (WISE 1049−5319)	Luhman 16A	6.5029±0.0011	L8±1[14]	10.7 J	14.2 J	10h 49m 15.57s	−53° 19′ 06″	501.557±0.082[15]	2013	one refuted planet (Ab[16] in 2017[17])
	Luhman 16B		T1±2[14]
WISE 0855−0714		7.26±0.13[18]	Y2	25.0 J		08h 55m 10.83s	−07° 14′ 42.5″	449±8[19]	2014	sub-brown dwarf
Wolf 359 (CN Leonis)		7.856±0.031	M6.0V[5]	13.44	16.55	10h 56m 29.2s	+07° 00′ 53″	415.16±1.62[20]	1919	flare star, has 2 known planets[21]
Lalande 21185 (BD+36°2147)		8.307±0.014	M2.0V[5]	7.47	10.44	11h 03m 20.2s	+35° 58′ 12″	392.64±0.67[22]	1801	one known planet (2019)[23]
Sirius (α Canis Majoris)	Sirius A	8.659±0.010	A1V[5]	−1.46	1.42	06h 45m 08.9s	−16° 42′ 58″	376.68±0.45[7]	N/A	brightest star in the night sky
	Sirius B		DA2[5]	8.44	11.34				1844
Luyten 726-8	Luyten 726-8 A (BL Ceti)	8.791±0.012	M5.5Ve	12.54	15.40	01h 39m 01.3s	−17° 57′ 01″	371.0±0.5[7]	1949	flare star (Archetypal member)
	Luyten 726-8 B (UV Ceti)		M6.0Ve	12.99	15.85
Ross 154 (V1216 Sagittarii)		9.7035±0.0019	M3.5Ve	10.43	13.07	18h 49m 49.4s	−23° 50′ 10″	336.123±0.064[7]	1925	flare star
Ross 248 (HH Andromedae)		10.2903±0.0041	M5.5Ve	12.29	14.79	23h 41m 54.7s	+44° 10′ 30″	316.96±0.13[7]	1925	flare star
Epsilon Eridani (BD−09°697)		10.446±0.016	K2V[5]	3.73	6.19	03h 32m 55.8s	−09° 27′ 30″	312.22±0.47[7]	150	three circumstellar disks, two suspected planets (AEgir (debated) and c) (2000 & 2002)[24]
Lacaille 9352 (CD−36°15693)		10.7211±0.0016	M0.5V	7.34	9.75	23h 05m 52.0s	−35° 51′ 11″	304.219±0.045[7]	1753	has 3 known planets[25]
Ross 128 (FI Virginis)		11.0074±0.0026	M4.0Vn	11.13	13.51	11h 47m 44.4s	+00° 48′ 16″	296.307±0.070[7]	1925	flare star, one planet (b) (2017)[26]
EZ Aquarii (Gliese 866, Luyten 789-6)	EZ Aquarii A	11.109±0.034	M5.0Ve	13.33	15.64	22h 38m 33.4s	−15° 17′ 57″	293.60±0.9[27]	1937	A & B flare stars
	EZ Aquarii B		M?	13.27	15.58				1937
	EZ Aquarii C		M?	14.03	16.34				1995
61 Cygni	61 Cygni A (BD+38°4343)	11.4008±0.0012	K5.0V[5]	5.21	7.49	21h 06m 53.9s	+38° 44′ 58″	286.08±0.03[7]	N/A	B flare star, first star (besides Sun) to have measured distance[28] possible circumstellar disk.
	61 Cygni B (BD+38°4344)		K7.0V[5]	6.03	8.31	21h 06m 55.3s	+38° 44′ 31″		1725
Procyon (α Canis Minoris)	Procyon A	11.402±0.032	F5V–IV[5]	0.38	2.66	07h 39m 18.1s	+05° 13′ 30″	286.05±0.81 [9][10]	N/A
	Procyon B		DQZ[5]	10.70	12.98				1844
Struve 2398 (Gliese 725, BD+59°1915)	Struve 2398 A (HD 173739)	11.4880±0.0012	M3.0V[5]	8.90	11.16	18h 42m 46.7s	+59° 37′ 49″	283.91±0.03[7]	1835	flare stars, star B has 2 known planets[29]
	Struve 2398 B (HD 173740)		M3.5V[5]	9.69	11.95	18h 42m 46.9s	+59° 37′ 37″		1835
Groombridge 34 (Gliese 15)	Groombridge 34 A (GX Andromedae)	11.6182±0.0008	M1.5V[5]	8.08	10.32	00h 18m 22.9s	+44° 01′ 23″	280.73±0.02[7]	1813	flare star, two suspected planets (Ac, 2017) and Ab, 2014)[30]
	Groombridge 34 B (GQ Andromedae)		M3.5V[5]	11.06	13.30				1813	flare star
DX Cancri (G 51-15)		11.6780±0.0056	M6.5Ve	14.78	16.98	08h 29m 49.5s	+26° 46′ 37″	279.29±0.13[7]	1972	flare star
Tau Ceti (BD−16°295)		11.753±0.022	G8Vp[5]	3.49	5.68	01h 44m 04.1s	−15° 56′ 15″	277.52±0.52[7]	N/A	one debris disk two planets (e and f) (2012), three suspected planets (d, g and h) (2012, 2017), two refuted planets (b and c in 2017)
Epsilon Indi (CPD−57°10015)	Epsilon Indi A	11.869±0.011	K5Ve[5]	4.69	6.89	22h 03m 21.7s	−56° 47′ 10″	274.80±0.25[7]	N/A	one planet (b) (2018)[31]
	Epsilon Indi Ba		T1.0V	12.3 J[32]		22h 04m 10.5s	−56° 46′ 58″		2003
	Epsilon Indi Bb		T6.0V	13.2 J[32]					2003
GJ 1061 (LHS 1565)		11.9803±0.0029	M5.5V[5]	13.09	15.26	03h 35m 59.7s	−44° 30′ 45″	272.245±0.066[7]	1995	has 3 known planets (2019)[33][34][35]
YZ Ceti (LHS 138)		12.1084±0.0035	M4.5V[5]	12.02	14.17	01h 12m 30.6s	−16° 59′ 56″	269.363±0.078[7]	1961	flare star, three planets (b, c, and d) (2017),[36] one suspected planet (e)
Luyten's Star (BD+05°1668)		12.199±0.036	M3.5Vn	9.86	11.97	07h 27m 24.5s	+05° 13′ 33″	267.36±0.79[37]	1935	two planets (b, c) (2017)[38]
Teegarden's Star (SO025300.5+165258)		12.496±0.013	M6.5V	15.14	17.22	02h 53m 00.9sg	+16° 52′ 53″	261.01±0.27[7]	2003	tentative radial velocity variation (2010)[35][39] has 2 known planets (2019)[40][41]
SCR 1845-6357	SCR 1845-6357 A	12.571±0.054	M8.5V[5]	17.39	19.41	18h 45m 05.3s	−63° 57′ 48″	259.45±1.11 [note 3]	2004	[35]
	SCR 1845-6357 B		T6[42]	13.3 J[32]		18h 45m 02.6s	−63° 57′ 52″		2006
Kapteyn's Star (CD−45°1841)		12.8294±0.0013	M1.5VI[5]	8.84	10.87	05h 11m 40.6s	−45° 01′ 06″	254.226±0.026[7]	1898	two known planets (b and c) (2014)[43]
Lacaille 8760 (AX Microscopii)		12.9515±0.0029	M0.0V[5]	6.67	8.69	21h 17m 15.3s	−38° 52′ 03″	251.829±0.056[7]	1753	flare star
Kruger 60 (BD+56°2783)	Kruger 60 A	13.0724±0.0052	M3.0V[5]	9.79	11.76	22h 27m 59.5s	+57° 41′ 45″	249.5±0.1[7]	1880	B flare star
	Kruger 60 B (DO Cephei)		M4.0V[5]	11.41	13.38				1890?
DEN 1048-3956		13.1932±0.0066	M8.5V[5]	17.39	19.37	10h 48m 14.7s	−39° 56′ 06″	247.22±0.12[7]	2001	[44][45]
Ross 614 (V577 Monocerotis, Gliese 234)	Ross 614A (LHS 1849)	13.424±0.049	M4.5V[5]	11.15	13.09	06h 29m 23.4s	−02° 48′ 50″	242.97±0.88[7]	1927	A flare star
	Ross 614B (LHS 1850)		M5.5V	14.23	16.17				1936
UGPS J0722-0540		13.43±0.13	T9[5]	16.52 J[46]		07h 22m 27.3s	–05° 40′ 30″	242.8±2.4[47]	2010	[48]
Wolf 1061 (Gliese 628, BD−12°4523)		14.0458±0.0038	M3.0V[5]	10.07	11.93	16h 30m 18.1s	−12° 39′ 45″	232.210±0.063[7]	1919	three planets (b, c, and d) (2015)[49]
Wolf 424 (FL Virginis, LHS 333, Gliese 473)	Wolf 424 A	14.05±0.26	M5.5Ve	13.18	14.97	12h 33m 17.2s	+09° 01′ 15″	232.2±4.3[50]	1919	flare stars
	Wolf 424 B		M7Ve	13.17	14.96				1941
Van Maanen's star (Gliese 35, LHS 7)		14.0744±0.0023	DZ7[5]	12.38	14.21	00h 49m 09.9s	+05° 23′ 19″	231.737±0.038[7]	1896	closest-known free-floating white dwarf, third-known white dwarf possible debris disk (1917), possible planet (b) (2004) (debated)
Gliese 1 (CD−37°15492)		14.1725±0.0037	M1.5 V[5]	8.55	10.35	00h 05m 24.4s	−37° 21′ 27″	230.133±0.060[7]	1884
WISE 1639-6847		14.30±0.56[note 4]	Y0.5	20.57 J	22.10 J	16h 39m 40.9s	−68° 47′ 46″	228.1±8.9[51]	2012
L 1159-16 (TZ Arietis, Gliese 83.1)		14.5843±0.0070	M4.5V[5]	12.27	14.03	02h 00m 13.2s	+13° 03′ 08″	223.63±0.11[7]	unknown	flare star, has 3 known planets[52]
Gliese 674 (LHS 449)		14.8387±0.0033	M3.0V[5]	9.38	11.09	17h 28m 39.9s	−46° 53′ 43″	219.801±0.049[7]	unknown	one planet (b) (2007)[53]
Gliese 687 (LHS 450, BD+68°946)		14.8401±0.0022	M3.0V[5]	9.17	10.89	17h 36m 25.9s	+68° 20′ 21″	219.781±0.032[7]	unknown	possible flare star, one planet (b) (2014)[54]
LHS 292 (LP 731-58)		14.885±0.011	M6.5V[5]	15.60	17.32	10h 48m 12.6s	−11° 20′ 14″	219.12±0.16[7]	unknown	flare star
WISE J0521+1025		16.3±4.2	T7.5[55]	15.26 J	16.95 J	05h 21m 26.3s	+10° 25′ 28″	217.5±40	2012	distance highly uncertain
LP 145-141 (WD 1142-645, Gliese 440)		15.1182±0.0023	DQ6[5]	11.50	13.18	11h 45m 42.9s	−64° 50′ 29″	215.737±0.032[7]	1917
G 208-44 G 208-45 (GJ 1245)	G 208-44 A (V1581 Cyg)	15.2090±0.0050	M5.5V[5]	13.46	15.17	19h 53m 54.2s	+44° 24′ 55″	214.45±0.07[7]	1967	flare stars
	G 208-45		M6.0V[5]	14.01	15.72	19h 53m 55.2s	+44° 24′ 56″		1967
	G 208-44 B		M5.5	16.75	18.46	19h 53m 54.2s	+44° 24′ 55″		1984
Gliese 876 (Ross 780)		15.2504±0.0054	M3.5V[5]	10.17	11.81	22h 53m 16.7s	−14° 15′ 49″	213.867±0.076[7]	unknown	four planets (d (2005), c (2001), b (1998), and e (2010))[56] two possible planets (f and g) (2014) (debated)
LHS 288 (Luyten 143-23)		15.7703±0.0056	M5.5V[5]	13.90	15.51	10h 44m 21.2s	−61° 12′ 36″	206.817±0.074[7]	unknown	one tentative planet (b) (2007)[35]
GJ 1002		15.8164±0.0098	M5.5V[5]	13.76	15.40	00h 06m 43.8s	−07° 32′ 22″	206.21±0.13[7]	unknown
Groombridge 1618 (Gliese 380)		15.8797±0.0026	K7.0V[5]	6.59	8.16	10h 11m 22.1s	+49° 27′ 15″	205.392±0.034[7]	1838	flare star, one suspected debris disk, one suspected planet (b) (1989) (tentative)
DEN 0255-4700		15.885±0.020	L7.5V[5]	22.92	24.44	02h 55m 03.7s	−47° 00′ 52″	205.33±0.25[7]	1999	[45]
Gliese 412	Gliese 412 A	15.983±0.013	M1.0V[5]	8.77	10.34	11h 05m 28.6s	+43° 31′ 36″	204.06±0.17[7]	1850s?
	Gliese 412 B (WX Ursae Majoris)		M5.5V[5]	14.48	16.05	11h 05m 30.4s	+43° 31′ 18″		1850s?	flare star
Gliese 832		16.1939±0.0034	M1.5 V[5]	8.66	10.20	21h 33m 34.0s	−49° 00′ 32″	201.407±0.043[7]	1910s?	possible flare star, two planets (b (2008) and c (2014))[57][58]
AD Leonis		16.1970±0.0055	M3.0V[5]	9.32	10.87	10h 19m 36.4s	+19° 52′ 10″	201.368±0.068[7]	1850s?	flare star, has 1 known planet[59]
GJ 1005	GJ 1005 A	16.26±0.76[note 4]	M4V[60]	11.48[60]		00h 15m 28.11s	−16° 08′ 01.6″	200.5±9.4[60]	unknown
	GJ 1005 B		M7V	?	?				unknown
System	Star	Distance[6] (Light-years (±err))	Stellar class	Apparent magnitude (mV[5] or mJ)	Absolute magnitude (MV[5] or MJ)	Right ascension[5]	Declination[5]	Parallax (mas (±err)) [5][note 1]	Discovery date [note 2]	Notes and Additional references
Designation						Epoch J2000.0

Quote from smAsh on January 13, 2020, 8:36 am

Most intrinsically bright object known in the Milky Way?

DENEB, a.k.a. Cygnus X-3, massive x-ray binary, located at about a 2600ly distance, Deneb is believed to be the celestial pole star at the other end of the 'precessional' cycle.  It's also a likely constant source of cosmic rays, which is super easy to say because of it's consistent 4.8 hour periodicity.

Quote from smAsh on January 14, 2020, 2:22 pm

The most Luminous Object Ever Imaged:

3C454.3.

https://blogs.nasa.gov/GLAST/category/uncategorized/page/2/

Quote from smAsh on January 15, 2020, 9:26 am

Fastest Neutron Star?

It's only traveling at 108 km/s

That's 241,589 mph, if you were wondering.

Quote from smAsh on January 15, 2020, 9:28 am

RX J1856.5−3754 (also called RX J185635−3754, RX J185635−375, and various other designations) is a nearby neutron star in the constellation Corona Australis.

Quote from smAsh on January 21, 2020, 6:46 pm

Most consistent likely cosmic ray point source (besides the Sun):

Deneb, a.k.a. Cygnus X-3, massive x-ray binary.