TransitofMercury–9May2016
SilverseaDiscoverer-12-March-2016
KrisDelcourte
[email protected]
www.flickr.com/photos/krisdelcourte/albums
TransitofMercury–9May2016
•  What?
–  2InnerplanetsMercuryandVenus
–  SomeMmestheypassinfrontoftheSun:themoveofthe
disksofMercuryorVenusovertheSun=theTransit
TransitofMercury–9May2016
Mechanics
Earth: 365.25 d
Mercury: 88 d
88/365.25 ≈ 0.24
TransitofMercury–9May2016
Mechanics
Earth: 365.25 d
Mercury: 88 d
88/365.25 ≈ 0.24
Next Inner conjunctie:
116 days (synodic period)
TransitofMercury–9May2016
•  When?
–  InnerConjuncMonofMercury
But,planeoforbitofMercurywithEclipMcplane:angle
of7°
AND
–  nearoneofits2knotswiththeEclipMcplane
TransitofMercury–9May2016
9May1970
10Nov1973
13Nov1986
6Nov1993
15Nov1999(tangent)
7May2003
8Nov2006
9May2016
11Nov2019
13Nov2032
7Nov2039
7May2049
9Novr2052
10May2062
11Nov2065
14Nov2078
7Nov2085
8May2095
10Nov2098
12May2108
TransitofMercury–9May2016
•  Transitsoccuraround8Mayand10Nov,datesthatthe
EarthispassingthroughtheknotlineofMercury
•  8May:atthedescendingnode
•  10Nov:attheascendingnode
•  TherearemoretransitsinNovthaninMay
•  NovemberTransitsoccurwithintervalsof7,13,33
years
•  MayTransitsoccurwithintervalsof13or33years
•  13or14percentury
TransitofMercury–9May2016
•  Novembertransit:Mercurynearperhelium,apparent
diameterof10”,1/194oftheSun’sdiameter.
•  Maytransit:Mercurynearaphelium,apparentdiameter
of12”,1/157oftheSun’sdiameter
•  Mercuryhasaveryexcentricorbit:e=0.2056
à OrbitalvelocityofMercuryinitsperheliumis50%faster
ascomparedtoaphelium
à LikelihoodtocrossthenodesisbiggerinNovember
TransitofMercury–9May2016
ObservingthetransitofMercury:
-  Ingress:i1,i2orfirstandsecond
contact.Willlast3.5minutes
-  Thenextphasebetweeningressand
egresswilllast7.5hour
-  Egress:e1,e2orthirdandfourth
contact.Willlastmorethan3minutes
TransitofMercury–9May2016
ObservingthetransitofMercury:
-  Timesareforageocentricobserver
-  Differencesforanyobserveronearth:
lessthan1minute
-  ForpreciseMmesforyourgeographic
locaMon,useonlinecalculator
TransitofMercury–9May2016
TransitofMercury–9May2016
ObservingthetransitofMercury:
- 
- 
- 
YoucanmeasuretheMmesofthe4contactswith
errormargin,geocoordinates(GPSbased)and
sendresultsto:[email protected]
Not easy: first and last contact: black planet
agains black background -> H-alpha filter +
some chromosphere or prominences may
help
Second and third contact: black drop effect TransitofMercury–9May2016
TheBlackDropEffect:
LinkbetweendarkdiscMercuryandthedarksky
DistorMonformofdiskMercury
Causedby:
-ImageblurringduetoatmosphericalcondiMonsand telescopediffracMon
-Limbdarkening
TransitofMercury–9May2016
TransitofMercury–9May2016
ObservingthetransitofMercury:
-  Visiblefrombegintoend:EastUSA,
Canada,West-Europe,EastofSouth
America,West-Africa
-  MagnificaMonneeded(50Mmes)
-  Safeviewing:
-  Solarfilterinfrontoftelescopeor
-  ProjecMonmethod
TransitofMercury–9May2016
History:
-  1627,KepplerpredictedaMercury
transitinNov1631andaVenustransit
inDec1631
-  FirstobservedbyPierreGassendi(Fr)on
7-Nov-1631
TransitofMercury–9May2016
History:
-  1663, Scottish mathematician James
Gregory proposed a method to
determine Earth - Sun distance
-  Inconsistent results due to small
parallax and difficulties with
measuring
-  1716, Edmund Halley developed a
method based on measuring 2nd and
3d contact for Transit of Venus.
TransitofMercury–9May2016
Solarparallax
TransitofMercury–9May2016
History:
- 
Expeditions in 1761 and 1769 to observe
transit of Venus gave first good results of
AU.
- 
Urbain Le Verrier, French mathematician,
based on transits of Mercury from 1632 to
1848, found (1859) that the precession of
Mercury’s orbit could not be explained by
the laws of Newton.
TransitofMercury–9May2016
History:
à Possible explanations:
•  flattening Sun,
•  existence of an unknown planet (Vulcan)
à In 1915: could be perfectly explained with
Einstein’s theory of general relativity
TransitofMercury–9May2016
7-May-2003:
Swedish 1-m Solar Telescope (SST) of the Royal Swedish
Academy of Sciences. Observers: Mats Löfdahl and Peter Detto
TransitofMercury–9May2016
8-Nov-2006:KilPeakObservatory,McMath-Pierce
Telescope,10minutesamerC1
W. Livingston and NSO/AURA/NSF
TransitofMercury–9May2016
SimultaneousTransits
•  Mercurius and Venus:
• March 69163;
• April 224508
•  Mercury during a partial solar eclipse :
5 July 6757
•  Venus during a partial zoneclips: 5 April
15232
Source:JeanMeeusandA.Vitagliano,2004
TransitofMercury–9May2016
InteresMnglinks:
• EclipseWise(FredEspenak):
hlp://eclipsewise.com/oh/tm2016.html
• TransitofMercuryCalculator(XavierJubier)
hlp://xjubier.free.fr/en/site_pages/
MercuryTransitCalculator.html
• Eyesafety:RalphChou:
http://www.mreclipse.com/Special/filters.html.