1. Symbiotic or planetary nebulae? Miguel Santander-García Romano L. M. Corradi Antonio Mampaso Asymmetrical Planetary Nebulae IV, Los Cancajos, La Palma, June 21, 2007

2. “Symbiotic Miras can do it” (APN II) Symbiotic nebulae are not planetary nebulae:  PPN/PN → A star ejecting its envelope and (later) ionizing it Symbiotic nebula → A hot star ionizing another star’s (mostly a Mira) envelope “Symbiotic Miras are wide binary systems with P orb ~ tens - hundreds years which strongly interact and produce large aespherical nebulae”

3. High density nebular cores with complex spectra similar to those of symbiotic Miras H α line profiles with broad wings similar to those of symbiotic Miras But some objects classified as PPN/PN show: NIR colors similar to those of symbiotic Miras

4. DENIS NIR dereddened diagram Schmeja & Kimeswenger 2001 A&A 377, L18 + 9 PPN

5. How could we distinguish them? PPN/PNSymbiotic Mira Morphology Ionised mass~0.1-1 M ⊙ (PN)~0.01 M ⊙ indistinguishable ! NGC 6537

6. Hen 2-104: Ionised mass estimate By assuming a distance of 800 pc (Schwarz 1989) and determining a density of n e = 300-1000 cm -3 for the Outer and Inner Lobes, Corradi & Schwarz (1993) estimated an ionised mass of ~0.02 M ⊙ for the nebula

7. D Jets = 3.5 ± 0.7 kpc Hen 2-104: Ionised mass estimate II VLT+ARGUS [SII] 6716 Å + [SII] 6731 Å Ionised mass of the nebula... ~0.2-1.7 M ⊙ !!! Santander-García et al. (in preparation)

8. Looking for the Mira in the NIR spectrum NIR spectrum dominated by the Mira Hen 2- 147 NTT+SOFI

9. Looking for the Mira in the NIR spectrum in the NIR photometric monitoring Hen 2- 147 P pulsation = 373 days

10. Quite strong dust continuum component, some features from the Mira Hen 2- 104 NTT+SOFI Looking for the Mira

11. Hora et al. 1999 ApJS 124, 195 Strong dust continuum component, no evidence of a cool companion Looking for the Mira

12. Smith 2005 MNRAS 342, 383 Strong dust continuum component, no evidence of a cool companion Looking for the Mira

13. M2-9: 4 records, no variability Photometric variability Mz 3: 6 records, small variabilty

14. M2-9: The Light House

15. Summary and conclusions So far we have found no evidence of a Mira in suspected symbiotics like Mz 3 or M2-9 The ionised mass of the nebula around Hen 2-104 is much larger than previously estimated From the observational point of view, it is sometimes difficult to distinguish symbiotic from genuine PPN/PN

16. Thank you!