The Effective temperature scale of M dwarfs from spectral synthesis

We present a comparison of low-resolution spectra of 60 stars covering the whole M-dwarf sequence. Using the most recent PHOENIX BT-Settl stellar model atmospheres (see paper by F. Allard, in this book) we do a first quantitative compari- son to our observed spectra in the wavelength range 550-950 nm. We perform a first confrontation between models and observations and we assign an effective tempera- tures to the observed M-dwarfs. Teff-spectral type relations are then compared with the published ones. This comparison also aims at improving the models' opacities.Comment: To be published in the on-line version of the Proceedings of Cool Stars 16 (ASP Conference Series) New version with bibliography correcte

Progress in Modeling Very Low Mass Stars, Brown Dwarfs, and Planetary Mass Objects

We review recent advancements in modeling the stellar to substellar transition. The revised molecular opacities, solar oxygen abundances and cloud models allow to reproduce the photometric and spectroscopic properties of this transition to a degree never achieved before, but problems remain in the important M-L transition characteristic of the effective temperature range of characterizable exoplanets. We discuss of the validity of these classical models. We also present new preliminary global Radiation HydroDynamical M dwarfs simulations.Comment: Submitted to Mem. S. A. It. Supp

Ageing effect on grooming activity in langur male bands (Semnopithecus entellus) in and around Jodhpur (India)

The study is based on grooming activity in different age class members of Semnopithecus entellus entellus all-male bands (AMB). All males seem to reach a peak in grooming frequency during and immediately following puberty and it is suggested that this peak corresponds to a period of establishing coalition bonds. High grooming rates may also be found in young adults who are actively and assertively challenging higher-ranking individuals. Finally, some old males exhibit paternalistic behavior toward young (generally pre-pubertal) males, which includes grooming, co-feeding and active defense by the older male. These observations are consistent with the hypothesis than grooming is an instrumental behaviour analogous to human gift exchange, which can be “used” by an individual for his ultimate benefit

Ecology and conservation of golden jackal (Canis aureus) in Jodhpur, Rajasthan

At north-west of India there is dry, semi arid region called as The Great Indian Thar desert. It lies between 24o and 35o 5’ N latitude and 70o 7’ and 76o 2’ E. Mammals of Thar desert includes the wolf (Canis lupus), the stripped hyaena (Hyaena hyaena), golden Jackal (Canis aureus), the Indian desert fox (Vulpes v. pusilla), wild bore (Susscrofaspc.), black buck (Antilo pecervicapra), blue bull (Boselaphus tragocamelus), chinkara (Gazella benneti), Hanuman langur (Semenopithecus entellus) etc. Golden Jackal is unique in distribution, occurrence, and survives at different environmental conditions in India including the hot desert. Present study has been carried out at Phitkasni village, situated south-east of Jodhpur city. Large population of golden Jackal has observed and data of their homerange, territory, inter-specific relation, conflict with human and mortality has been studied. It is concluded that regular monitoring and proper conservation management is needed in this area so Jackal and other carnivore like wolf, desert fox and hyena can also be conserved

Detection and characterisation of two VLM binaries: LP 1033-31 and LP 877-72

Using the high-resolution near-infrared adaptive optics imaging from the NaCo instrument at the Very Large Telescope, we report the discovery of a new binary companion to the M-dwarf LP 1033-31 and also confirm the binarity of LP 877-72. We have characterised both the stellar systems and estimated the properties of their individual components. We have found that LP 1033-31 AB with the spectral type of M4.5+M4.5 has a projected separation of 6.7$\pm$1.3 AU. Whereas with the spectral type of M1+M4, the projected separation of LP 877-72 AB is estimated to be 45.8$\pm$0.3 AU. The binary companions of LP 1033-31 AB are found to have similar masses, radii, effective temperatures, and log $g$ with the estimated values of 0.20$\pm$0.04 $\rm{M}_{\odot}$, 0.22$\pm$0.03 $\rm{R}_{\odot}$, 3200 K, 5.06$\pm$0.04. However, the primary of LP 877-72 AB is found to be twice as massive as the secondary with the derived mass of 0.520$\pm$0.006 $\rm{M}_{\odot}$. The radius and log $g$ for the primary of LP 877-72 AB are found to be 1.8 and 0.95 times that of the secondary component with the estimated values of 0.492$\pm$0.011 $\rm{R}_{\odot}$ and 4.768$\pm$0.005, respectively. With an effective temperature of 3750$\pm$15 K, the primary of LP 877-72 AB is also estimated to be $\sim$400 K hotter than the secondary component. We have also estimated the orbital period of LP 1033-31 and LP 877-72 to be $\sim$28 and $\sim$349 yr, respectively. The binding energies for both systems are found to be $\gt$10$^{43}$ erg, which signifies both systems are stable.Comment: 14 pages, 6 figures, accepted for publication in MNRA

Study of the impact of tourists and local visitors / feeders on free-ranging Hanuman langur population in and around Jodhpur, Rajasthan (India)

The Jodhpur city of Rajasthan has many tourist places where Hanuman langurs habitually feed on the food given by the visitors to them. The interactions were studied between Hanuman langurs and the visitors in and around Jodhpur by means of interviewing the visitors and direct observations of the behaviour of Hanuman langurs and visitors. Most (82.2%) of the observed interactions involved the presence of food; only in 17.8% of the interactions we observed langurs threatening or chasing the visitors. Some differences, however, emerged between what the visitors reported in the interviews and what we observed. Most respondents (76.1%) reported in the interviews that hostile interactions were started by monkeys, whereas analysis of the direct interactions showed that 47.3% of such interactions were initiated by visitors and only 39.6% by Hanuman langurs. Moreover, 83.9% of the visitors affirm them to feed Hanuman langurs, while 70.2% of them report having seen other visitors feeding them. On the basis of the above results, it would be beneficial to establish an educational program, providing information about the behaviour of Hanuman langurs and the consequences that feeding them could have on their behaviour and on their interactions with visitors

Latitudinal Pigmentation Variation Contradicts Ultraviolet Radiation Exposure: A Case Study in Tropical Indian Drosophila melanogaster

The effects of ultraviolet radiation (UV) on the animal body have been reported in many studies, and melanin has emerged as a protective mechanism. In smaller insects such as Drosophila, replicated patterns of geographical variation in pigmentation have been observed on multiple continents. Such patterns are particularly pronounced on the Indian subcontinent where several species show a parallel cline in pigmentation traits. However, the potential role of UV exposure in generating the observed patterns of pigmentation variation has not been addressed. Here, we examine the association between UV intensity and body pigmentation in D. melanogaster natural populations collected along the latitudinal gradient of the Indian subcontinent. A strong negative relationship was observed between UV intensity and body pigmentation. This analysis clearly indicates that, in the sampled populations, pigmentation variation is independent of UV exposure and related selection pressures. Patterns of pigmentation in natural populations from the Indian subcontinent are better predicted by latitude itself and temperature-related climatic variables

The Effective Temperature Scale of M dwarfs

Despite their large number in the Galaxy, M dwarfs remain elusive objects and the modeling of their photospheres has long remained a challenge (molecular opacities, dust cloud formation). Our objectives are to validate the BT-Settl model atmospheres, update the M dwarf T eff -spectral type relation, and find the atmospheric parameters of the stars in our sample. We compare two samples of optical spectra covering the whole M dwarf sequence with the most recent BT-Settl synthetic spectra and use a \c{hi}2 minimization technique to determine Teff . The first sample consists of 97 low-resolution spectra obtained with NTT at La Silla Observatory. The second sample contains 55 mid-resolution spectra obtained at the Siding Spring Observatory (SSO). The spectral typing is realized by comparison with already classified M dwarfs. We show that the BT-Settl synthetic spectra reproduce the slope of the spectral energy distribution and most of its features. Only the CaOH band at 5570{\AA} and AlH and NaH hydrides in the blue part of the spectra are still missing in the models. The Teff-scale obtained with the higher resolved SSO 2.3 m spectra is consistent with that obtained with the NTT spectra. We compare our Teff scale with those of other authors and to published isochrones using the BT-Settl colors. We also present relations between effective temperature, spectral type and colors of the M dwarfs.Comment: 16 pages, 6 figures, accepted for publication in A&