Skip to main content

Special Notice #178: Request for observations of NSV 99 (khi Peg)

AAVSO Special Notice #178

Request for observations of NSV 99 (khi Peg)
November 16, 2009

Further to AAVSO Alert Notice 405 (2009 October 2), Dr. Brian Espey, Trinity College, Dublin requests the AAVSO's assistance in monitoring the bright semi-regular variable NSV 99 (= khi Peg) in conjunction with observations by the Hubble Space Telescope.  HST is scheduled to perform ultraviolet spectroscopy on 2009 November 26 (JD 2455161 - 162), and nightly V-band photometry is requested to measure the optical brightness and correlate it with the UV spectral features.  Observations are requested to begin now (2009 November 16, JD 2455152) and to continue through the end of November 2009.

The following information was given in Alert Notice 405, and is repeated here for convenience:

Photoelectric observers are asked to obtain nightly V-band photometry of NSV 99 using the following comparison and check stars:

Comparison:     HR 22 (SAO 91734, "87 Peg")
                RA/Dec(J2000): 00:09:02.4247 ,  18:12:43.067
                V=5.532, (B-V)=1.038 (Mermilliod and Mermilliod 1998)

Check:          HR 131 (SAO 74084, "52 Psc")
                RA/Dec(J2000): 00:32:35.4859 ,  20:17:39.539
                V=5.367, (B-V)=1.069 (Mermilliod and Mermilliod 1998)

Note that these stars will not appear on VSP-generated charts smaller than A scale.  Both comparison and check stars are several degrees away, so please try to observe as close to the meridian as possible.  DSLR observers and wide-field CCD observers should use the same comparison and check stars as above.  There are few suitable near-field comparison stars, so standard CCD imaging is not recommended.

When submitting CCD or DSLR data, please be clear as to what comparison stars you use.

NSV 99 (= khi Peg) is located at the following (J2000) coordinates:

RA,Dec: 00:14:36.20 , +20:12:24.0

Finder charts for NSV 99 may be plotted using VSP:

Note that NSV 99 is itself a comparison star used for visual observing, so the chart will have a "48" label next to the star.

Please submit observations to the AAVSO using either of "NSV 99" or "KHI PEG".

This AAVSO Special Notice was prepared by M. Templeton.

Information on submitting observations to the AAVSO may be found at:


A Special Notice archive is available at the following URL:

Subscribing and Unsubscribing may be done at the following URL:
AAVSO 49 Bay State Rd. Cambridge, MA 02138 617-354-0484