The description is written for those who are interested in using this data for solar system minor bodies discovery/follow-up or other scientific purposes.
This document was last updated on 2006 December 21.
The Lulin Sky Survey (LUSS) is maintained at Lulin Observatory, one of the best site for astronomical observing purpose in southeast Asia. The facilities include a 16-inch Ritchey-Chrétien made by RC Optical System, and a back-illuminated CCD made by Apogee, so it produces high quality data which can reach R~21.2mg. As the data may be useful for other researching purpose besides solar system minor bodies, the Graduate Institute of Astronomy, National Central University in Taiwan, host of Lulin Observatory, permitted LUSS to share its data onto the Internet. The data will be placed on the server of World Data Center for Astronomy, which host by National Astronomical Observatories of mainland China. The data for public will be in FITS format, each image is ~8Mbytes. They will be reduced by USNO-A 2.0 and with flat/dark applied.
Some detailed information will be listed here:
- Telescope: 0.41-m (16-inch) f/8.8 Ritchey-Chrétien reflector + f/6.25 focal reducer
- CCD: Back-illuminated Apogee Alas U42, 2098 x 2048 pixels
- Field of view: 27'x27'(no focal reducer); 38'x38'(focal reducer installed)
- Pixel scale: 0.8"/pixel (no focal reducer); 1.1"/pixel (focal reducer installed)
Currently there are five observing modes in LUSS (announced in LUSS Electronic Circular 78).
- Normal Scan Field (NS): Image names start with "SF" and follow field number (1, 2, 3, ... or a1, a2, a3, ...). Each field contained several smaller "blocks" (now is 9 blocks), each block covered 38'x38' (27'x27' before focal reducer installed), the block number will follow field number. (e.g. SF14 = Field 1, Block 4) Each block will be visited three times, with about 20 minutes interval. Exposure for NS is 60 or 90 seconds (can be seen in FITS head -- but is 240 seconds before July 4, 2006). These images can reach R~21.2mg under decent sky conditions.
- Quick Scan Field (QS): Image names the same with NS, each field also contained nine blocks, but most of them are under 4-pass mode (each block visited four times), with ~5 minutes interval. Exposure for QS is 20 seconds, with limiting magnitude down to ~19.3 R. It can covered ~100 arcdeg^2 per night.
- Follow-up Field (FU): Usually the name will started with the target's designation or observer-assigned codes.
- Vulcanoids Field (VUL) and Kreutz Field (KRZ): Rarely used mode, it uses 20-second exposure to cover very small elong. regions, the limiting magnitude is various, typically from R~14 to R~18.
- Others include NEO confirmations or photometry targets. Usually the name started with the target's designation or observer-assigned codes.
We strongly encourage users to use NS and/or QS as they are "standard" observations. Please do not use other modes if not necessary.
As LUSS is a non-professional project, it's not yet fund by governments or any organizations. We are unable to take time to write an index and query tool for data users. However, we do have a plan for evaluating such a program in future. We will put news here if have any progress on this topic.
Now the users may have two ways to look up data other than viewing one image after one:
- Look up the observing list instead. The investigators will customize the list for then-night before observing, these lists have been put on line and can be viewed. Please note that in many occasion, some part of the list is not done due to bad weather or telescope problem, so not all the coordinates have been imaged.
- Use the MPC Sky Coverage. It can print the coverage information of LUSS in half a year.
After July 4, 2006, all data under "Scan Field" mode is proceed by automatic program, so bad reduced or 2-pass images only would not get proceed. It means there should be many undetected targets in the images. Some of them are known, but quite a number of them are new. To make it more convenient for potential asteroid hunters, we try to visit the same region several days apart, for an easier multi-night linkage.
Here are config files for Astrometrica: No focal reducer version or focal reducer installed version. For new comers, here is a guide written by Marco Langbroak about how to recover and discover new asteroids in SkyMorph database, which is quite similar to LUSS archive besides a powerful query tool.
But different from SkyMorph, we do give the credit to the volunteer if he or she could managed to discover new minor bodies in LUSS archive. That is, if his/her discoveries become numbered, the volunteer has the "naming right". In such case, the discoverer should sent the citation to us and we will forward it to CSBN.
If you have used our data for serious work, please let us know, and acknowledge the data is produced by Lulin Sky Survey, which is supported by Graduate Institute of Astronomy, National Central University in Taiwan.
If you have questions and/or suggestions on LUSS data archive, feel free to contact our Principal Investigator, Quanzhi Ye at [email protected]. More information will be put on this page if necessary, keep on checking.
(c) Copyright 2006-2008 Lulin Sky Survey