For a certain project I had created a number of photometric catalogs, each one corresponding to a specific observing field. I would like to construct the final (merged) one but for this I needed to add a unique source identifier at the beginning of each row. I decided to create a F#-**** tag for each […]
Astronomy Archive
Merging catalogs and creating unique identifier in bash
By grigoris | Filed in AstronomyAn amazing drawing of Saturn
By grigoris | Filed in AstronomyIn the era of imaging even from our cell phones making a drawing of a planet seems redundant. However, this is certainly a different perspective of a direct experience at the eyepiece of a telescope. And the final result can be fascinating, such as this drawing from Paul G. Abel, using the Clark telescope (a […]
Building an observatory in Syria
By grigoris | Filed in AstronomyAt the last issue of CAP journal (No. 23, Feb 2018) we find the article “The World at a Glance: Highlights from IAU National Outreach Contacts” that provides short news from the IAU National Outreach Contacts. And for Syria we read: “Mohamad AlAssiry: Despite the political situation, the Syrian Astronomical Association was building an observatory […]
New paper on the circumstellar environment of galactic B[e] supergiants
By grigoris | Filed in AstronomyFinally, after some years of work, it has been accepted for publication in MNRAS. Resolving the kinematics of the disks around Galactic B[e] supergiants Grigoris Maravelias, Michaela Kraus, Lydia S. Cidale, Marcelo Borges Fernandes, Maria L. Arias, Michel Curé, Georgios Vasilopoulos B[e] Supergiants are luminous evolved massive stars. The mass-loss during this phase creates a […]
Catching a supernova just before it happens
By grigoris | Filed in AstronomyVictor Buso is a really very lucky man! On September 20, 2016 we wanted to test his new camera mounted on a 40-cm Newtonian telescope. He pointed to the spiral galaxy NGC 613 because it was at that time located near the zenith. He took a series of 20s exposures spanning approximately an hour and […]
Skinakas return!
By grigoris | Filed in AstronomyYesterday was the first night that I found myself at Skinakas Observatory. Even though some years have passed, there are really minor changes. The mountain welcomed us with great weather (scarce clouds, humidity close to 50%, and almost no wind at all!), while the seeing proved to be really good (~1″).
Mixing a transient object with … Mars!
By grigoris | Filed in AstronomyIn the Astronomer’s Telegram #11448 [1] it is announced that a very bright (almost 1st magnitude) transient object is found between the Lagoon and the Trifid nebulae. No other object has been found in the region and the source itself was not visible some days earlier. Within less than an hour later a second follow […]
Seminar talk at NOA
By grigoris | Filed in AstronomyAs I am waiting my flight to Heraklion, I thought that I should post the talk that I gave earlier today at the National Observatory of Athens, Greece: “B[e] Supergiants: a missing part from the massive star puzzle?” Abstract: Massive stars affect strongly the insterstellar medium through their intense stellar winds and their rich chemically […]
Proposal brainstorming …
By grigoris | Filed in AstronomyFrom our previous meeting.
IRAF’s identify error – center not found
By grigoris | Filed in AstronomyDuring the last few days I have struggled a bit with the wavelength calibration of some long-slit spectra. When using the identify task of IRAF I found that I could select (“m”ark) only some of the lines, without any clear indication why the rest were not recognized (some were indeed stronger but others were equal […]
