| discov_num |
notes |
refcode |
| HEN 2 |
Delta-M is in K band. |
|
|
LSPM J0657+6219 = GJ 3417. Law et al (2008) derive a distance of |
Law2008 |
|
11.4 +/-0.3 pc and a projected separation of 17.5 +0.5/-0.5 au. |
|
|
Estimated spectral types are M4.5 and M6.5. |
|
|
GJ 3417 = LHS 1885. If taken at face value, the body of astrometric |
|
|
points that exists for this target does not make sense. Three epochs |
|
|
of astrometry exists: One from Henry et al. (1997) taken in 1996 (rho |
Hen1997 |
|
= 2.0" and theta = 220deg), one from Law et al. (2008) taken in 2005 |
Law2008 |
|
(rho = 1.5" and theta = 320deg), and our data point taken in 2012 (rho |
|
|
= 1.4" and theta = 240deg). Given that background objects can be |
|
|
firmly excluded, this would imply an enormously fast orbital motion |
|
|
since the binary would move from 220deg to 320deg and then back to |
|
|
240deg within 16 years, which is impossible for such a low-mass binary |
|
|
with a ∼17 au semi-major axis. However, the astometry becomes entirely |
|
|
sensible in an orbital motion framework if we impose a 90deg phase |
|
|
shift on the Law et al. (2008) position angle such that it is 230deg |
|
|
instead, giving a continous motion of 20deg in 16 years. In Janson et |
|
|
al. (2012), we suggested an equal phase shift for similar reasons for |
Jnn2012 |
|
the Law et al (2008) data point in the 15553178+3512028 binary system. |
Jnn2014 |
|
Estimated age 60-300 Myr; masses 0.30 +/- 0.14 and 0.15 +/- 0.08 Msun; |
|
|
a ~16.5 au. |
Jnn2014 |
| refcode |
metd |
author |
reference |
| Hen1997 |
Si - |
Henry, T.J., Ianna, P.A., Kirkpatrick, J.D., & Jahreiss, H. |
1997AJ....114..388H |
| Hen1997 |
|
AJ 114, 388, 1997 |
|
| Jnn2012 |
Cl j |
Janson, M., Hormuth, F., Bergfors, C., Brandner, W., Hippler, S., Daemgen, S., |
2012ApJ...754...44J |
| Jnn2012 |
+E2 |
Kudryavtseva, N., Schmalzl, E., Schnupp, C., & Henning, T. |
|
| Jnn2012 |
|
ApJ 754, 44, 2012 (some recalibrated measures published in Jnn2014b) |
2014ApJS..214...17J |
| Jnn2014 |
A - |
Janson, M., Bergfors, C., Brandner, W., Kudryavtseva, N., Hormuth, F., |
2014ApJ...789..102J |
| Jnn2014 |
+Cl |
Hippler, S., & Henning, T. |
|
| Jnn2014 |
|
ApJ 789, 102, 2014 |
|
| Law2008 |
Ss - |
Law, N.M., Hodgkin, S.T., & Mackay, C.D. |
2008MNRAS.384..150L |
| Law2008 |
|
MNRAS 384, 150, 2008 |
|
| Law2008 |
|
All measures of known pairs in Law2008 appear to be off by 90 (or 270) degrees. |
|
| Law2008 |
|
Corrected and N code code added to measure. |
|
