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[vsnet-campaign 280] Two long-term monitoring campaign NSV stars

Two long-term monitoring campaign NSV stars

   As reported in vsnet-chat, two NSV stars possibly identified with ROSAT
sources (possible dwarf novae) are introduced to our long-term campaign
program to look for the possible next outburst.  Look for recoveries!

   Two objects are NSV00907 and NSV01436.

Subject: [vsnet-chat 3317] NSV00907

  Another possible ROSAT identification.  Large-amplitude variable: possible
cataclysmic object??

  NSV00907:

024457.3 +273113 (2000.0) NSV00907 ? 12 (16 P -

  ROSAT:

024459.1 +273125 (2000.0) 1RXS-F_J024459.2+273126 0.024 0.99 0.62

  According to John Greaves in vsnet-chat 3319, the object is ROSS 182,
appearing in AJ 37, 155 (1927).

Subject: [vsnet-chat 3326] NSV01436

   Another large-amplitude NSV - ROSAT identification!

   NSV01436:

040238.3 +425035 (2000.0) NSV01436 ? 12 16 P -

   ROSAT:

040239.3 +425036 (2000.0) 1RXS_J040239.4+425037 0.136 0.92 0.31

Subject: [vsnet-chat 3328] re NSV 1436

This star is 4th in a list of candidate variables found serendipitously
by Frank E Ross in the 1920s whilst doing blink comparator work during
searches for large proper motion stars.

He used duplicate exposures with two instruments for a field to avoid
plate defects.

His comparison plates were ones made at an earlier date by E E Barnard.

There is no note as to whether Barnard's plates were single exposures or
not.  I assume not.

Thus if a star is uniquely present or brighter on Ross's plates than on
Barnard's, we have the likelihood of a variable.

If the star is uniquely present or brighter on Barnard's plates, I
suppose plate errors cannot be ruled out.

The tabular data suggests that both sets of plates went down to a
similar level of guesstimated mag 15.

ROSS 4 = NSV 1436 was mag 11 on Barnard's 1st Nov 1904 plate, and mag 15
on ROSS's 14th Jan 1925 plates.

Cheers

John

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