.: Astronomy Research - Photographic Musings - Timeless Recordings - Contact Info :.

3/24/2024: My former graduate cosupervisor (Dr. David J. Lane) passed away, and in all actions he was an individual of profound kindness, and together with his lovely partner Michelle they continue supporting Nova Scotia's Community College (the Lane Family Endowment).

My primary research interests pertain to improving the cosmic distance scale and characterizing the interstellar medium. That helps foster determinations of the expansion rate of the Universe, and facilitates efforts to delineate the spiral structure of the Milky Way and constrain astrochemistry (e.g., celestial molecules). I conduct research in part as a member of ESO's VVV Survey and SMU/MSVU, while helping run a college astronomy program abroad (WCC). Regarding the Galaxy, maps of its spiral structure are uncertain and exhibit striking differences. Indeed, some 150+ years after Alexander suggested the Milky Way was spiral in nature there lacks consensus on its morphology (e.g., number of spiral arms, central bar(s)). Certain research indicates that perfect spiral patterns ineptly describe features near the Sun, and the possible scenario of the Sun residing within a spur implies that such features are not unique. Our work on the astronomical distance scale likewise aims to provide improved distances to galaxies and star clusters, such as the famed Pleiades and Andrews-Lindsay 1 (also known as ESO 96-4 and VdBH 144). Andrews-Lindsay 1 is a rare open cluster granted it hosts a planetary nebula, designated PHR J1315-6555 or PN G305.3-03.1 (Parker et al. 2006 & 2011, Majaess et al. 2007 & 2014, Frew 2008). The planetary nebula phase is a later evolutionary stage for stars exhibiting a mass approximately 1-8 times that of the Sun, and thus provides a tantalizing glimpse into the Sun's future.

For example, the cosmic distance scale can be anchored in part via deep near-infrared main-sequence fits to star clusters (e.g., Majaess et al. 2011), and thereafter applied to those clusters hosting a class of pulsating stars designated classical Cepheids (see Turner 2012). The scale can be tied to numerous open clusters exhibiting matching near-infrared and revised Hipparcos distances (the Hyades, α Per, Praesepe, Coma Ber, IC 2391, IC 2609, and NGC 2451). An objective is to avoid deriving distances to Cepheid-hosting clusters using a discrepant benchmark (e.g., the Pleiades and Blanco 1), namely to avoid propagating ambiguity into a Cepheid calibration employed to characterize the Universe's expansion. The revised Hipparcos parallax for the Pleiades star cluster implied a distance of 120.2±1.9 pc, whereas the near-infrared analysis yielded a further distance of 138±6 pc. The latter result was recently supported by the Gaia parallax mission, although incessant vetting is likewise required for that space probe. The multi-cluster near-infrared approach was applied to determine distances to various clusters, such as the (dissolving) one hosting Delta Cephei (de Zeeuw et al. 1999, Turner & Burke 2002, Majaess et al. 2012), which is the namesake for the class of Cepheid stars. Interestingly, Fragkou et al. 2019 recently discovered that the planetary nebula BMP J1613-5406 is a member of the star cluster NGC 6067, which also hosts two Cepheids (e.g., Coulson & Caldwell 1985, Majaess et al. 2013), thereby providing a lucrative opportunity to constrain stellar evolution. Additional information on Cepheids in star clusters can be found at astronomer David Turner's website, and for a comprehensive review on the broader topic of Cepheids see Turner 2012.

Below is an abbreviated list of published work carried out in concert with a team of research collaborators, and a more comprehensive listing of our work is indexed in NASA's astrophysics data system, ResearchGate, Google Scholar, and ORCID.

A view of the Galaxy as traced by planetary nebulae (black dots) and globular clusters (blue dots), from Figure 1 in Majaess 2010.




Figure 1 from Majaess et al. 2012, who investigated a new star cluster at coordinates J2000 02:54:31.4 +69:20:32.5 which is absent in optical light (left panel) owing to significant obscuring dust, but is apparent in a mid-infrared image from NASA's Wide-field Infrared Survey Explorer (right panel, ~3.4 microns). Numerous class I young stellar objects were discovered using WISE data, and the host star cluster was also cataloged as object 230 in Majaess 2013. Indeed, Issac et al. 2020 subsequently hypothesized that the cluster emerged from the collision of interstellar clouds (see their Figure 10), and is linked to an adjacent longer-wavelength Planck cold clump source (G133.50+9.01).


Below are articles contributed to the Universe Today astronomy e-magazine for a broad audience, and they are less formal than the academic publications above:




Figure 2 in Majaess 2013 highlights a subset of the (sub)clusters replete with protostars.


Curious students stumble across various star clusters, and desire additional information. They were for the most part identified as younger embedded (sub)clusters in the work designated Discovering protostars and their host clusters via WISE (the digitized CDS catalog is here), which relied largely on observations from NASA's WISE spacecraft. Essentially a first-order hybrid near and mid-infrared relation (JHKs-W1W2W3W4) was constructed to identify (sub)clusters replete with class I/f protostars. Such targets can possess diverse designations say when surveyed in separate portions of the electromagnetic spectrum, and (inevitably) cross-matched upon subsequent dedicated investigations adopting a holistic multiwavelength examination. For example, Mohr-Smith et al. 2017 examined the region surrounding the extreme O-supergiant LSS 2063, and they noted, "Dutra et al. 2003 did catalogue an NIR cluster essentially coincident with LSS 2063 and, more recently, Majaess 2013 has noted this location as a plausible clustering of young stars based on raised mid-IR emission (Majaess 133, in the associated catalogue). ... Avedisova 2002, in her list of star-forming regions, also notes a coincidence between radio emission in this location and RAFGL 4120 (an earlier mid-IR detection effectively). So here, finally, the optical has caught up and the very much larger group of ionizing stars, helping LSS 2063 shape this environment, has emerged." Maiz-Apellaniz et al. 2020 returned to this intriguing region and noted, "Villafranca O-006 = Gum 35 = Majaess 133 ... This is the most overlooked object in our sample, with only a few significant references in the literature. ... It is close to NGC 3603 in position in the sky (2 deg away) and extinction (Av~5), and the two distance error bars overlap, so it is possible the two objects are physically associated, as suggested by Mohr-Smith et al. 2017." Camargo et al. 2015 & 2016 surveyed Majaess 24 and substructure therein, 30, 45, and 78. Regarding the latter, Camargo et al. 2015 conveyed that, "Majaess 78: our analyses suggest that this embedded cluster lies in the Perseus spiral arm at a distance of 3.2±0.5 kpc and presents an age of approximately 3 Myr (million years)." Issac et al. 2020 hypothesized that the newly formed star cluster identified by Majaess et al. 2012 using mid-infrared WISE data at coordinates J2000 02:54:31.4 +69:20:32.5 emerged from "a bona fide cloud-cloud collision" (see their Figure 10). That cluster hosts numerous class I young stellar objects (YSOs), and was also cataloged as object 230 in Majaess 2013. An image displayed above conveys the region sampled in the optical portion of the electromagnetic spectrum, and the mid-infrared WISE image (~3.4 microns). The cluster is absent in the optical owing to sizable extinction by interstellar dust, and Issac et al. 2020 connected it to a proximal longer-wavelength Planck cold clump source (G133.50+9.01). Chen et al. 2016 hinted that the pulsating star ASASJ160125-5150.3 (a Cepheid) could be a member of Majaess 170, and they noted, "Majaess 170 is a small open cluster with a size of 5' (Dias et al. 2002). ASAS J160125−5150.3 is located 7' from the cluster centre. This cluster has not been studied previously. The distance modulus, colour excess, and age we determined are μ0=11.30±0.28 mag (d=1.8±0.3 kpc), E(J-H)=0.38±0.03 mag, and log(t)=8.1±0.2, respectively. ... The Cepheid’s proper-motion and distance-modulus measurements imply that it is a high-probability cluster member. The age of ASAS J160125−5150.3, derived from its period, is approximately log(t)=7.8±0.1, which implies a difference with respect to the host cluster of less than 0.3 dex." An alternate possibility to consider is that the cluster (Majaess 170) is significantly younger than the Cepheid (ASAS J160125−5150.3), which would negate a connection, and further research is desirable. Below is an image compiled by Ferreira et al. 2019 of the broader field hosting NGC5999 and Majaess 166 (see their Figure 3), and they indicated that, "Majaess 166 was identified as a very young cluster with a size of 4' (Majaess 2013), and it is easily distinguished from UFMG 3 in DSS images for its nebulous nature, the cluster being still embedded in the progenitor gas cloud. Being probably distant clusters projected in the direction of UFMG 3, Teutsch 81, and Majaess 166 could be better investigated using near-infrared bands, possibly allowing their stellar content to be distinguished from field stars."

Diverse researchers are mobilizing to advance humanity's celestial knowledge in a pyramid-like fashion, each adding a block in a broad collaboration.



Figure 3 from Ferreira et al. 2019 displaying NGC5999, Majaess 166, and other star clusters (see also T. Nowakowski's phys.org article on the broader Ferreira et al. 2019 results).


Lastly, curious students likewise often stumble upon astronomer David Balam's discovery of the main-belt asteroid 304233 Majaess, and inquire about the object. The asteroid exhibits a slightly inclined orbit as shown below (i~12.6 deg), and lies in the main asteroid belt between Mars and Jupiter. The full suite of parameters for the asteroid can be viewed at NASA's JPL Small-body Database Browser, and it adheres to an average distance of 2.9 AU and features an orbital period of 4.8 years. The asteroids linked to my former graduate supervisors are 27810 Daveturner and 117032 Davidlane. Warner et al. 2011 concluded that, "the Hungaria asteroid 27810 Daveturner ... (has a) synodic rotation period of P = 540 ± 20 h".

Orbit of main-belt asteroid 304233 Majaess from NASA's JPL Small-body Database Browser, and it features orbital parameters of a~2.9 AU, i~12.6 deg, and P~4.8 years. The asteroid was discovered by astronomer David Balam.