5. White Dwarf WD 1145+017 Photometric Monitoring Observations by an Amateur Observer
B. L. Gary, 5 of 5 web pages, Last updated 2018.11.27 03 UT

1 of 6 - 2015.11.01 to 2016.01.21:  LC Observations  - 1st  set of LCs, for 2015/16 observing season   
2 of 6 - 2016.01.17 to 2016.07.13:  LC Observations  - 2nd set of LCs, for 2015/16 observing season    
3 of 6 - 2015.11.01 to 2016.07.13:  LC Observations  - 3rd set of LCs, for 2015/16 observing season  (N = 158) + Overview, Results & Model Speculations 
4 of 6 - 2016.10.25 to 2017.06.18:  LC Observations  - 4th set of LCs, for 2016/17 observing season 
5 of 6 - 2017.10.23 to 2018.06.18:  LC Observations  - 5th set of LCs, for 2017/18 observing season  (YOU ARE HERE)
6 of 6 - 2018.11.09 to present         LC Observations  -  6th set of LCs, for 2018/19 observing season
 
Status Update: 

The following are recent phase-folded LCs.





Trends can be seen in the following plot of model fits for recent phase-folded LCS;


Figure 2. Model fits to the last four phase-folded LCs.


Figure 3. "Activity level" for past 3.5 years.


Figure 4a. Waterfall plot for 2017/18 observing season.

Links on this web page:
    Appeal for observations with telescopes of size 1- to 2-meters
    List of observing sessions 
    Observing session observations   
    Finder image 
    Data exchange files
    References & related links  
    My collaboration policy 

Appeal for "Sweet Spot" Telescope Observations (1- to 2-meters)

We need better photometric monitoring than I can provide with an amateur 14-inch telescope. I'm limited to 1-minute exposures with SNR that is only sufficient for characterizing 5% dips (that last for 10 minutes or longer). Brief observations with large telescopes reveal the presence of 1% dip structure with 10-second temporal variations. There's a "sweet spot" for telescope size that will allow good SNR while permitting full orbit (4.5-hour) observing sessions at weekly intervals. I think that sweet spot aperture is 1 to 2 meters. This is an appeal for someone to take the lead in obtaining telescope time with a 1 to 2-meter telescope for weekly 5-hour observing sessions for the duration of the 2017/18 observing season (now to June). 

List of observing sessions   

Data file for 2017/18 observing season: link
2018.06.18-BG  
2018.06.13-BG  
2018.06.01-JH  
2018.05.18-BG  
2018.05.13-BG   
2018.05.08-BG  
2018.05.04-JH  
2018.05.01-JH  
2018.04.30-JH  
2018.04.24-JH  
2018.04.23-BG  
2018.04.21-BG  
2018.04.16-BG  
2018.04.10-BG  
2018.04.06/07-JH  
2018.04.05/06-JH  
2018.04.04/05-JH  
2018.04.02/03-JH  
2018.03.27-BG     
2018.03.16-BG  
2018.03.15-BG  
2018.03.12-BG  
2018.03.10-BG  
2018.03.08-JH  
2018.03.06-BG  
2018.02.26-JH  
2018.02.25-JH 
2018.02.24-JH 
2018.02.23-TK/BG  
2018.02.23-JH  
2018.02.23-BG  
2018.02.22-JH  
2018.02.21-JH  
2018.02.10-TK  
2018.02.09-TK  
2018.02.08-TK  
2018.02.08-BG  
2018.02.05-BG  
2018.01.25-BG  
2018.01.11-BG 
2018.01.05/06-JH  
2018.01.05-BG  
2018.01.01-JH  
2017.12.31-JH  
2017.12.30-JH 
2017.12.29 
2017.12.28-JH 
2017.12.27-JH
2017.12.23 
2017.12.20  
2017.12.08  
2017.11.20  
2017.11.16  
2017.11.12 
2017.11.10 
2017.10.23

Observing Sessions  

2018.06.18-BG



LCb 




2018.06.13-BG  





 LCb 

2018.06.01-JH  





2018.05.18-BG  





LCb

2018.05.13-BG  





LCa  LCb 

2018.05.08-BG  





LCa  LCb 

2018.05.04-JH  





2018.05.01-JH  



2018.04.30-JH  



2018.04.24-JH  



2018.04.23-BG  



LCa  LCb 

2018.04.21-BG 



LCa  LCb 

2018.04.16-BG 



LCb 

2018.04.10-BG  



LCa  LCb 

2018.04.06/07-JH  



2018.04.05/06-JH  



2018.04.04/5-JH



2018.04.02/03-JH  



2018.03.27-BG  



LCa  LCb 

2018.03.16-BG  

Changed optics: inserted Optec focal reducer lens. Wind degraded seeing for most of the observing session.



LCa  LCb 

2018.03.15-BG  



LCa  LCb 

2018.03.12-BG   clouds



LCb 

2018.03.10-BG   clouds



LCa   LCb 

2018.03.08-JH  



2018.03.06-BG  



LCa  LCb 

2018.02.26-JH  



2018.02.25-JH 



2018.02.24-JH 



2018.02.23-TK/BG




Zoom of pohase region with "wiggles" showing repeat of pattern one orbit apart.

LCa  LCb  

2018.02.23-JH  



2018.02.23-BG  



2018.02.22-JH  







2018.02.21-JH  



2018.02.10-TK  



LCa  LCb 

2018.02.09-TK  


Note: 40-sec exposures

LCa  LCb 

2018.02.08-TK  



LCa  LCb 

2018.02.08-BG  




FWHM = 3.2 minutes.

LCa  LCb 

2018.02.05-BG  



LC_b   LC_a 

2018.01.25-BG    



LC_b  

2018.01.11-BG  



LC_mag  

2018.01.15/06-JH  



2018.01.15-BG



LC_mag_a   LC_mag_b  

2018.01.01-JH  



2017.12.31-JH 



2017.12.30-JH



2017.12.29-BG 



17.12.29-BG(a) and 17.12.29-BG(b)

2017.12.28-JH 



2017.12.27-JH



2017.12.23-BG 



17.12.23-BG(a) and 17.12.23-BG(b) 

2017.12.20-BG  DataExchangeFile  



17.12.20-BG(a) and 17.12.20-BG(b)

2017.12.08-BG   DataExchangeFile  







2017.11.20-BG 



2017.11.16-BG



2017.11.12-BG

Thin cirrus overcast makes data dubious. I've concluded that this data should be "rejected."



2017.11.10-BG



2017.10.23-BG  

This is the first observation of the season. All data is at hgh air mass and the session is short.



Finder Image


WD1145 is at 11:48:33.59 +01:28:59.3 (J2000). FOV = 27 x 18 'arc, northeast at upper left.

My Collaboration Policy

Please don't ask me to co-author a paper! At my age of 77 I'm entitled to have fun and avoid work. Observing and figuring things out is fun. Writing papers is work. Besides, most people really don't care about what others have done. (Google "WD 1145+017" and among the several pages of lame links none point to my web pages.)

My light curve observations will be "in the public domain" for this observing season (2017/18). This includes a download of all LC observations, which I invite anyone to use. If my data is essential to any publication just mention this in the acknowledgement section (no co-authorship, please).

Data Exchange Files

Data exchange files are available in two formats: light curve details (normalized flux for each image) and dip statistics (asymmetric hypersecant model fits for each dip). The first of these is available for download here, but I recommend that anyone using these data check with me for updates (since I sometimes find errors and post the corrected files here). Data exchange files of the second format (dip stat's) will be available here in due time.

    Light curve data exchange file for 2016.01.27 to 2016.07.13 download:  Link (fluxes for every exposure)
    Light curve data exchange file for 2016.10.25 to 2017.04.30 download:  Link (fluxes for every exposure)  

References

    Vanderburg, Andrew and Saul A. Rappaport, 2018, "Transiting Disintegrating Debris around WD 1145+017," arXiv 
    Rappaport, S. B. L. Gary, A. Vanderburg, S. Xu, D. Pooley & K. Mukai, "WD 1145+017: Optical Activity During 2016-2017 and Limits on the X-Ray Flux," MNRAS, arXiv 
    Xu, S., S. Rappaport, R. van Lieshout & 35 others, "A dearth of small particles in the transiting material around the white dwarf WD 1145+017," MNRAS link, preprint arXiv: 1711.06960 
    Vanderburg et al, 2015, "A Disintegrating Minor Planet Transiting a White Dwarf," Nature, 2015 Oct 22, arXiv:1510.063387
    Croll et al, 2105, "Multiwavelength Transit Observations of the Candidate Disintegrating Planetesimal Orbiting WD 1145+017," ApJ, arXiv:1510.06434 
    Gaensicke et al, 2015, "High-Speed Photometry of the Disintegrating Planetesimal at WD 1145+017: Evidence for Rapid Dynamical Evolution," arXiv :1512.09150
    Rappaport, S., B. L. Gary, T. Kaye, A. Vanderburg, B. Croll, P. Benni & J. Foote, 2016, "Drifting Asteroid Fragments Around WD 1145+017," MNRAS, arXiv:1602.00740
    Alonso, R., S. Rappaport, H. J. Deeg and E. Palle, 2016, "Gray Transits of WD 1145+017 Over the Visible Band," Astron. & Astrophys., arXiv:1603.08823
    Petit, J.-M and M. Henon, 1986, Icarus, 66, 536-555 (link)
    Veras, Dimitri, Philip J. Carter, Zoe M. Leinhardt and Boris T. Gansicke, 2016, arXiv 
    Gary, B. L., S. Rappaport, T. G. Kaye, R. Alonso and F.-J. Hamsch, "WD 1145+017 Photometric Observations During Eight Months of High Activity," 2017, MNRAS, 465, 3267-3280. PDF  or arXiv  
    Hallakoun, N., S. Xu, D. Maoz, T.R. Marsh, V. D. Ivanov, V. S. Dhillon, M. C. P. Bours, S. G. Parsons, P. Kerry, S. Sharma, K. Su, S. Rengaswamy, P. Pravec, P. Kusnirak, H. Kucakova, J. D. Armstrong, C. Arnold, N. Gerard, L. Vanzi, 2017, Earth and Planetary Astrophysics, arXiv 1702.05486
    Farihi, J., L. Fossati, P. J. Wheatley, B. D. Metzger, J. Mauerhan, S. Bachman, B. T. Gansicke, S. Redfield, P. W. Cauley, O. Kochukhov, N. Achilleos & N. Stone, "Magnetism, X-ras, and Accretion Rates in WD 1145+017 and other Polluted White Dwarf Systems, MNRAS, arXiv
    Tom Kaye presentation at 2016 Society for Astronomical Science meeting: link   

Related Links  
    Mukremin Kilic's pro/am search of dusty WDs for dips:  https://www.nhn.ou.edu/%7Ekilic/Docs/dusty.html
    Some observing "good practices" for amateurs (book): Exoplanet Observing for Amateurs
    Hereford Arizona Observatory (HAO):  http://www.brucegary.net/HAO/
    Tutorial for faint object observing techniques using amateur hardware: http://brucegary.net/asteroids/  
    Master list of my web pages & Resume

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WebMaster:   Nothing on this web page is copyrighted. This site opened:  2017 November 12