The New Milky Way

a wide-field survey of optical transients near the Galactic plane

The NMW survey

The New Milky Way survey aims to detect bright (V<13.5) optical transients near the Galactic plane using an automated wide-field (8x6 deg.) system capable of surveying the whole Milky Way area visible from the observing site in one night. The system is built using low-cost mass-produced components. The transient detection pipeline is based on the open source VaST software. The first results of the survey include the discovery of Nova Sagittarii 2012 No. 1 as well as two X-ray emitting cataclysmic variables 1RXS J063214.8+25362 and XMMSL1 J014956.7+533504. The rapid detection of Nova Sagittarii 2012 No. 1 enabled us to conduct its X-ray and UV observations with Swift 22 hours after discovery (~31 hour after the outburst onset). All images obtained during the transient search survey are available online (please use the image archive access form). The survey parameters are summarized in the table below. A more detailed description may be found in this arXiv e-print.

**The New Milky Way survey parameters**
Optics:	Canon 135 mm f/2.0	Accuracy at V~11:	0.1m (absolute)
CCD camera:	SBIG ST-8300M		0.05m (internal)
	(blue-sensitive chip)	Images per field:	2 or 3 per night
Image size:	3352 x 2532 pix		(dithering)
Optical filter:	none	Stars per frame:	~20000
Equatorial mount:	HEQ-5 Pro	Images per night:	~200
Field of view:	8 x 6 deg.	Milky Way imaging time:	5 hr (January)
Pixel scale:	8.4"/pix		10 hr (April)
Exposure time:	20-40 sec	Processing time:	up to 7 hr/night
Limiting magnitude:	V ~ 14.5	Results inspection time:	up to 4 hr/night
Transient detection limit:	V < 13.5

Unfortunately, at present the NMW survey is not run continuously. Instead, it consists of individual observing sessions of varying length separated by large gaps. The current time distribution of the observations is presented in the plot:

The users should be warned that time stamps of observations obtained before 2013 are accurate to only within 2 minutes. The later observations have a sub-second accuracy of their time stamps.

The sky distribution of image centers:

Image Archive

You may use this form to access the NMW images of a given sky region. It may take a minute or two to extract the requested images. Please click just once and wait for results.
You may also access the full images directly. (It takes a while to load the image list.)

If you use data from the NMW archive in a scientific publication, please cite the e-print describing the survey.

Gallery

The NMW camera.

A star field in Sagittarius imaged with the NMW camera (full frame).

An overall view of the observing site.

The NMW observing site marked on Google Maps.

External links

The VaST software for variable star search. The NMW processing pipeline is based on VaST.
Web-based lightcurve analysis tool - allows one to perform a period search using Lafler & Kinman (1965, ApJS, 11, 216) and Deeming (1975, Ap&SS, 36,137) methods.
Times of minima calculator - a simple web-based tool to calculate times of minima from light elements.
TIFF2FITS - a simple C program (based on CFITSIO and libtiff) which converts TIFF images to 16-bit FITS format. May be useful for processing scanned photographic plates.
OMC2ASCII - a C program (based on CFITSIO) which converts INTEGRAL/OMC lightcurves from FITS table to simple ASCII table. May be useful if you don't want to install the Off-line Science Analysis (OSA) software just to get to INTEGRAL/OMC data.
Online FITS-to-ASCII lightcurve converters are available for INTEGRAL/OMC and SuperWASP data. The converters are based on the OMC2ASCII code.

If you have any questions or suggestions, please fell free to contact the authors via e-mail kirx[at]scan.sai.msu.ru

NMW survey team, 2011-2015