Central Bureau for Astronomical Telegrams
IAUC 8289: 2000 CQ_114; IRAS 05436-0007
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Circular No. 8289
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Mailstop 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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2000 CQ_114
D. C. Stephens and K. S. Noll, Space Telescope Science
Institute; and W. Grundy, Lowell Observatory, report the detection
of a binary companion to the transneptunian object (TNO) 2000
CQ_114 (cf. MPEC 2000-J45, MPO 27660), from observations made on
2003 June 6.003-6.031 UT with camera 2 (NIC2) of the Near-Infrared
Camera Multi-Object Spectrometer on the Hubble Space Telescope
(HST). The TNO was observed in the F110W and F160W filters
(yielding approximately J and H bands), with two exposures in each
filter. The two components are well resolved in all four images.
PSF fitting was used to determine a separation between the two
components of 0".178 +/- 0".005 at p.a. 255.6 +/- 6 deg; this
corresponds to a separation of approximately 2.4 pixels at the NIC2
pixel scale (0".075 per pixel). The spacecraft tracked the motion
of 2000 CQ_114 as it moved > 0".25, and the relative position of
the two components remained the same during that time. As 2000
CQ_114 was then 45.544 AU from the earth, the projected separation
of the objects in the plane of the sky is 5880 +/- 200 km.
Magnitudes for the components: primary, [F110W] = 22.243 +/- 0.020,
[F160W] = 21.787 +/- 0.015; secondary, [F110W] = 22.849 +/- 0.031,
[F160W] = 22.086 +/- 0.017. Earlier observations of 2000 CQ_114
with the HST Wide Field Planetary Camera 3 (scale 0".1 per pixel)
on 2002 Jan. 6.112-6.139 show no conclusive evidence for a binary,
though the data are possibly consistent with an unresolved pair at
a separation of less than or equal to 0".12; magnitudes for the
combined system in these images are: V = 23.86 +/- 0.12; R_c =
23.16 +/- 0.08; I_c = 22.53 +/- 0.08.
IRAS 05436-0007
C. Aspin, Gemini Observatory; and B. Reipurth, University of
Hawaii, report on observations made at the Gemini 8-m telescope on
Mauna Kea. The near-infrared counterpart to IRAS 05436-0007 (cf.
IAUC 8284) was as bright as J = 11.1, H = 9.0, and K_s = 7.4 on
2004 Feb. 3 UT in observations with the NIRI instrument. This is
3.6, 3.2, and 2.9 magnitudes brighter in these bands, respectively,
than the 2MASS values from 1998 Oct. 7. A K-band NIRI spectrum
from the same night shows strong CO band-head emission and the
Brackett_gamma line in emission. An optical spectrum obtained with
the GMOS instrument on 2004 Feb. 14 shows a prominent H_alpha
emission line with P-Cyg profile and a red continuum. These
characteristics are consistent with IRAS 05436-0007's currently
undergoing an 'EXor' eruption (Herbig 1977, Ap.J. 217, 693; Herbig
et al. 2001, PASP 113, 1547).
(C) Copyright 2004 CBAT
2004 February 16 (8289) Daniel W. E. Green
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