There was quite a bit of "Venus Transit Fever" on the Internet during the few days leading up to the transit as well as several days afterwards. The plethora of pictures, videos and articles was quite impressive. However there are 2 videos that stand out in my mind....
First a video complied by a friend and fellow Raleigh Astronomy Club member, Chris Cole. All footage was obtained with his own equipment while he was visiting New Mexico:
The second video is from NASA and the footage was obtained from the Solar Dynamics Observatory in space:
On the afternoon of June 5th, 2012 (the morning of June 6th on other parts of the planet) the black silhouette of Venus was observed crossing the face of the sun. This passing in front of the sun is what astronomers call a transit. The next time Venus will transit the Sun, from the Earth’s vantage point, will be December of 2117. Yes, 2117; that’s 105 years from now!
I coordinated a viewing event for Raleigh Astronomy Club members and their guests hosted by the Prairie Ridge Ecostation (near the PNC Arena, formerly the RBC Center). Over 70 people, including my parents and my 2 oldest children attended the event and more than 24 members’ telescopes were on hand to provide excellent views of the transit.
Most of Tuesday afternoon was rather cloudy and the possibility of the viewing the transit from the Raleigh area was in doubt. Thankfully by around 5:30pm the Western horizon began to clear up. Around 6:04pm a friend of mine, Doug, called out, “We have first contact!” That is when the leading edge of Venus began to cross the face of the sun. At that point everyone turned their gaze to the nearest telescope or viewing device.
There were various methods used for safe viewing from Eclipse Glasses, welder’s glass (#14), commercially made white light solar filters, home-made white light solar filters, H-Alpha Solar telescopes, and a few different types of projection methods including a Sun Funnel design and Solar Projector. I had a commercial solar filter on my 8" Celestron SCT, my son's dob had a homemade white light filter and I had made a Sun Funnel for a small refractor I have.
Not only where there lots of people observing, we also had quite a few imagers with dedicated telescopes and cameras taking pictures of this rare event. Additionally smart phones were a popular accessory for observers at the eyepiece snapping mementos of the transit. Below are a few images from some Raleigh Astronomy Club imagers that were at the event.
While clouds did occasionally block the view of the transiting Venus, most of the viewing event was not interrupted by clouds. Although the transit event would take more than 6 ½ hours to complete, once the sun set, you could no longer observe the transit from your local vantage point. At around 7:45pm the sun began to be obscured by clouds low on the horizon. With the sun at only 3 degrees or so above the horizon, that spelled the end of our views from Prairie Ridge.
Overall it was a great event with tremendous turnout, a fantastic venue and a once in a lifetime transit. For more information about the Transit of Venus, check out the following link http://www.transitolfvenus.org/.
Below are a video and a few more photos taken of the observing event:
On my list of objects to view from my own telescope (a 1994
Celestron 8” SCT), has been Quasar 3C 273.
Aesthetically speaking, this object has zero value, it looks like a very
faint star. However what makes this
object so interesting is its origin and its distance.
Quasars are the compact, central region of a massive galaxy
surrounding its super-massive black hole.
What powers these quasars are the accretion discs around the
super-massive black holes. As the theory
goes, quasars were more common in the earlier universe which is why most are so
far away from us (i.e. – the further away an object we see from Earth with
further back in time we are seeing the object).
While 3C 273 is visually unimpressive, the fact that what you see the
super hot, luminous accretion disc of material spinning around a super-massive
back hole makes the observing of this object pretty cool in my book.
The other amazing aspect of this observation is the
distance. Various sources differ on the
distance of this object, anywhere from 1.918 billion light years out to 2.5
billion light years. The fascinating aspect
of this, at least for me, is that photons that I observed, that interacted with
my telescope and my eye’s retina were emitted from 3C 273 and had be traveling through
space for over 2 billion years! Put
another way, that’s a little more than 14.5% of the history of our universe (13.7
billion years old) or about 44% of the history of our Earth (4.5 billion years
old). 2 billion years ago here on Earth
there was no life on land, only simple organisms in the oceans; Oxygen was
starting to replace CO2 in our atmosphere.
Finding 3C 273 was a bit tricky due to how dim it is, it
varies from 11.7 to 13.2 but averages about 12.8. I found the following web site very helpful
in locating and observing 3C 273, http://washedoutastronomy.com/content/3c-273-quasars-are-easy. The coordinates of 3C 273 (J2000 are RA: 12 :
29.1 DEC: +02 : 03.1)
Once I was in the general area, it was difficult to isolate which faint object was 3C 273. Using the
finder charts that are include in the link above made it a bit easier. Below is a photo that will approximate the
view. I looked for a “W” shape and based
on the charts I knew the top center of the “W” was the quasar. It is the brightest of the objects that make
up the central part of the “W.”
Here is an excerpt from one of the charts. 3C 273 is about 12.8 magnitude and therefore should be brighter than 13.5 mag. star off to the right (just outside the red circle in the chart below).
It took a little going back and forth but I was finally able
to nail down the orientation of the stars and patterns on my charts/printed materials with the flipped view from my 8" SCT. This was a great
hunt!
Thursday night I spent some time with fellow RAC members Mark L.and Ian H. (separately) while at the Staunton River Star Party. We were looking through my 8” SCT for the super nova SN2012aw that had been detected last week in the Leo galaxy, M95. After much back and forth on Stellarium, star charts and printed aids, we confirmed the bright object that looked like a foreground star was indeed the supernova SN2012aw.
I read a comment online from someone doing photometry work on SN2012aw that they measured it at 12.67 mag. which might be why we were able to see it with my 8” scope (although the skies were pretty dark – measured at 6.2 mag. by fellow RAC member Phyllis L).
Lastly, check out the blog post of Astronomer Phil Plait. His March 23, 2012 blog post is around the progenitor of SN2012aw that has been found in previous Hubble Space Telescope pictures. Check out the blog post and video >> HERE.
On Tuesday November 8th, 2011 asteroid 2005 YU55 which is about the size of an aircraft carrier buzzed the Earth within 201,700 miles (324,600 kilometers). As a point of reference, our moon is 238,000 miles away! Even though asteroids of this size pass by Earth frequently, the last time a space rock this large came as close to Earth was in 1976, although astronomers did not know about the flyby at the time. The next such close flyby will take place in 2028, when an asteroid called 2001 WN5 will pass about halfway between the Moon and Earth.
The path of Asteroid 2005 YU55, when it was visible in the skies above North America, took it thru the constellation of Pegasus. Although there was an almost full moon washing out the sky, conditions were clear.
Several Raleigh Astronomy Club members and I attempted to capture a view of this asteroid either visually or via a camera. I captured the asteroid visually from the club’s viewing site near Jordan Lake. I was finally able to track this sucker down at around 9:35 when it flew thru an asterism of a backwards 7, this was one of the intercept points I had calculated.
There were times I could make out the asteroid very clearly in my 8" and others when I had to use averted vision. I thought it could have been the seeing causing this variability but then noticed the surrounding stars of similar brightness were not fading, so it must have been varying in brightness (the asteroid’s rotation perhaps?). The asteroid was moving quite fast thru my field of view. It took perhaps a minute to move from edge to edge in my eyepiece, which is about ¾ of a degree (or 42”). I tracked it visually until almost 11:45pm, occasionally losing it and having to calculate new intercept plots based on the data points gathered from the IAU Minor Planet Center.
This was my first time observing an asteroid; half the fun was the hunt! It was truly a great observing opportunity!
As experienced amateur astronomers we are often asked, “What telescope should I buy?” However that question would be better phrased as follows, “What telescope should I buy that meets my needs and budget?” The key words are “Needs” and “Budget.”
You can certainly find a lot of information on the internet about buying a telescope, especially a beginner telescope. Not all of it is necessarily in your best interest, though. I started out in 2004 as a complete beginner and have slowly worked up to a level of experience and knowledge where I am able to teach others how to get started by running the Raleigh Astronomy Club’s ‘Telescope Tune Up Clinics’ for the past several years. Let me share my own experience with you in hopes of saving you a lot of time, money and frustration.
A FEW KEY POINTS:
I would be remiss if I did not at least try to convince to you start out in astronomy with just a good set of binoculars. This was the advice I was given and I promptly ignored; I just wanted a telescope! I find a lot of beginners also feel like I did, they really want a telescope and do not see any value in using binoculars to start. By the way, I eventually bought two pairs of binoculars and really enjoy sometimes just observing with them and not using a telescope.
If you follow in my foot steps and jump right into buying a telescope, be sure you understand aperture. Aperture is the size of the main mirror or lens, this is usually the diameter of the opening or clear part of the telescope. The larger the aperture the more light a telescope collects. Contrary to popular belief, an astronomical telescope’s main purpose is to gather light not magnify. So the more light your scope gathers, the dimmer the object you can see in your telescope. You will want to maximize the aperture for your given needs, budget and portability/storage requirements.
For more great advice on getting your first telescope, here is a great video on purchasing tips for you to view. Our own Raleigh Astronomy Club member, Doug Lively, was interviewed for this segment on a local Raleigh TV show, http://www.mycarolinatoday.com/2010/08/telescope-101/.
QUESTIONS TO ASK YOURSELF:
Which is the best type of telescope to get? That is a lot like asking, “I want to buy a screwdriver, what is the best kind?” The correct answer is “that all depends on what screws you will be using, Phillips, Slottled, Allen, etc.” Below are some questions you need to ask yourself in order to guide you to the best telescope for your individual needs:
How much should I spend? The sky can be the limit here so you need to set a realistic budget. There are good scopes available even for modest budgets. However you should devote at least 25% of your budget for accessories like eyepieces, reference material (charts, books, planispheres, etc.). You can always purchase additional accessories later but you will need a few eyepieces and other basics to start.
What do I want to look at? Do I want to get into astrophotography? The rationale behind this question is that certain types of telescopes are better for viewing certain objects than others. Also, certain equipment is better suited for astrophotography.
Where will I use my telescope? Will I use my telescope in overly light polluted skies, suburban skies or very dark skies? Even the biggest aperture telescope cannot compensate for light polluted skies. On the other hand even a small aperture telescope under really dark skies will amaze you.
How portable does my telescope need to be? Do you live in an apartment on the 3rd floor or in a house with a good sized garage for storage? Carrying an 8” Dobsonian scope up and down several flights of stairs will get very tiring very quickly. Does your telescope (and gear) need to fit in your car for transportation to other sites?
How much “help” do I want from my telescope? Some telescopes automatically calibrate themselves and with very little input from you and align themselves quite accurately. These fully automated scopes are almost fool proof and will find objects for you and track them as the Earth rotates. However this may not be the best way to learn the night sky. Other telescopes have motors that once you find the object through the telescope, the motors will keep up with the rotation of Earth. Still other scopes are completely manual and you must do all the finding and tracking. Naturally, the more automation, generally the more money you will spend.
ANSWERS:
Budget:
The first question addresses how much you want to spend. If you set your budget too low, you get into a price point where the quality of telescopes is just plain poor. You’ll be hard pressed to find quality telescopes on the used marked for less than $150.00 and brand new under $250. Don’t be afraid to buy used, just make sure it’s coming from someone who knows about the telescope and astronomy, took care of the telescope and is reputable. Sites like www.cloudynights.com and www.astromart.com are great sites for buying used equipment. In a nutshell, be prepared to spend at least $200 for a used telescope and accessories and at least $300 if you by new.
On the otherhand, it is possible to over spend. The last thing you want to do is spend $2,400 on a full featured telescope only to realize astronomy is not your cup of tea.
Remember to earmark about 25% for accessories like eyepieces, barlows, charts/planispheres and dew prevention.
Types of Telescopes:
The second question is targeting what type of telescope will best fit your needs. There are 3 main types of telescopes: Refractor, Reflector and Compound or Catadioptric. Rather than go into the differences here, here is great 4 minute video from YouTube posted by Orion that best explains the differences between the types.
Each type of telescope has its’ pros and cons. Some telescopes excel at planetary observation while others are more suited to deep sky work. However since many beginners will not know what objects they will prefer to view, it’s hard to try and make the decision to by which telescope. Therefore I recommend not even worrying about that just yet. Instead, focus on the portability and ease of set up. Certain scopes are more portable than others and certain mounts are easier to set up than others. Dobsonian reflectors are the easiest to set up but tend to be the biggest of the scopes but also offer the most bang for your buck.. Catadioptrics are the most compact type of telescope and are considered the “jack of all trades” telescope but they are more expensive. Refractors offer some of the best contrasts and are great for imaging but are the most expensive per aperture. One recommendation I feel very strongly about is for beginners to stay away from equatorial mounts for your first scope. While there are great for tracking, they are complex and are not beginner friendly to set-up and use.
If astrophotography is something you want to pursue, I recommend that you study up and learn the basics first. Equipment specific to taking images can be very costly.
Size Telescope:
What size scope is best for you? If you plan to go observing from several different locations then you need a portable telescope but one that will offer at least a decent amount of aperture. A 6” telescope or 150mm is the minimum aperture I would recommend that you start with. Storage of your astronomy equipment is another consideration. If you can spare a corner in your garage or in a closet, a 6” to 8” dob will store nicely in a spot like that.
Beware of the idea that bigger is better. A wise man once told me that the best size telescope is the one you will use. If the scope is too much of a hassle to carry out and set up because it’s too bulky, it won’t get used. A 10” or 12” scope will provide some great views of dim objects but these size telescopes are heavier and take longer to set up and will also require more trips back and forth from where you store them to where you observe.
To GOTO or Not To GOTO:
The night sky is a vast and wondrous sight to behold, but how much do you want to know about it? Are you looking to only observe but not necessarily learn the night sky or understand celestial movements? It used to be the case that scopes with computers (GOTO or Push –to-go) were more complicated and required a fair amount of knowledge to calibrate. This is no longer the case. An board computer or locator aid can greatly improve the productivity of your observing sessions as well as remove a fair amount of frustration in locating objects. However, there is still something to be said about first learning the basics first (i.e. – learning the constellations, how to locate objects, how to star hop). In school, you don’t give children calculators and let them skip learning basic mathematical skills. Again, it just depends on your goals.
GOTO and Push-to-go features cost money. If you are on a modest budget, you’ll want more of your purchasing dollars to be invested in the optics of the telescope and less to the mount and gadgets. Stay away from low priced GOTO/Push-to-go scopes (under $300 for new); the quality is just not there. Consider Orion’s Intelliscope line of dobsonians with Push-to-go (aka – digital setting circles), they start at the 6” range and go to 12”. Another very good line of GOTO telescopes is Celestron’s NexStar telescopes.
SPECIFIC TELESCOPE RECOMMENDATIONS:
Higher End (Over $1,200) - Celestron NexStar 8:
This 8” catadioptric, specifically a Schmidt Cassegrain telescope (or SCT) is actually quite portable, easy to set up and easy to use. As this telescope is a full GOTO scope, it will track objects as they move through the sky once the telescope has found them. If you want a telescope that will break down nicely and fit in your trunk, this is it. Smaller aperture (less expensive) models are available but 8” is a really nice size and will allow you to “go deep” with regards to astronomical objects. However with an SCT you’ll need a few extras such as a dew shield or dew heater. Also consider a portable 12v battery to power the scope (and dew heater, if you use one) as those 8 on board AA batteries will go very quickly and can only power scope motors and the computer. If you have to navigate several flights of stairs, this might not be an ideal scope as you’ll have to carry the scope, tripod, dew shield, eyepiece case and anything else (charts, reference items, red flashlight, etc. It’s easily 2 or 3 trips to carry everything.
Mid Range Dobsonian ($500 to $1,000) - Orion’s 6” or 8” IntelliScope:
You will be hard pressed to find a better manufacture of telescopes for beginners and intermediate astronomers than Orion (www.telescope.com). Orion’s IntelliScope line is one of their best and is very well respected in the amateur astronomy field. The computer locator is fairly easy to set up and works quite well. Plus Dobs by nature are easy to set up and use. If you are looking for some good aperture, some help in locating objects and have the room to store a dob, then the IntelliScope line is for you. To align the computer you do need to be able to identify and center in your scope’s eye piece 2 bright stars. The 8” version is about 6 to 7 pounds heavier and a bit more bulky. However the 8” scope comes with a focuser that accommodates 2” sized eyepieces as well as 1.25”. The 6” will only accommodate 1.25” eyepieces.
Modest Range ($300 to $500):The Orion Classic Dobs or Zhumell:
XT8 is part of its ‘Classic’ dob line. This is a pretty basic dob but it does everything it’s supposed to do, it does it well, it’s fairly affordable and it is built quite well. The 8” dob is a bit bulkier than a 6” but the tube will still fit across the back seats of your car or even your trunk. If your trunk is big enough, it might also fit the base. However if portability and a small storage foot print are critical for you, an 8” dob might not be the ideal choice for you.
The Orion XT6 is small enough to fit in the truck or hatch of most cars but still has enough aperture that will allow you to view deep space objects. I was treated to a very nice surprise a few months after buying my 6 year old son an XT6. Using it, M106 (the Sombrero Galaxy) was nicely visible from rural/suburban skies. As with the XT8, the XT6 has a handle on the base which allows you to carry the scope and base in one hand and an eyepiece case in the other. If you are looking for a scope that you can carry everything in one trip and set up quickly, you’ll be hard pressed for find anything better than the Orion XT6.
In the 8” range, Zhumell also makes a good scope. I have heard good things about these telescopes, but I have only seen one once during the day; the build quality of the scope was very nice. Also for the money, the Zhumell scopes include more than the same sized Orion scopes. Zhumell scopes can be purchased through telescopes.com.
SOME CLOSING POINTS:
If you really want to do more research, check out this Report from CloudyNights:
One last piece of advice, join a local astronomy club! The amateur astronomy community as a whole wants to share their knowledge and experience with the public. You’ll see evidence of this on just about any astronomy club’s website in their outreach section. This outreach not only extends to the general public but more so to new members. You’ll find experienced members are more than happy to answer questions and offer advice; all you have to do is ask. Remember, they were once beginners too.
This blog post is intended to help parents, grandparents, aunts, uncles, etc. looking to purchase a telescope for that special little child that is fascinated by the night sky. As an amateur astronomer, active member in local astronomy club and facilitator of astronomy clinics, I believe I am well qualified to discuss telescopes for beginners.
Be Careful When Buying A Telescope: Please be very careful when purchasing a telescope as a gift! I make this plea as I'm certain you do not want that special little person to be frustrated and unhappy with the gift you give them. Most inexpensive (less than $200.00 retail) telescopes that you can purchase at Toys-R-Us, Wal-mart, department stores, camera stores, etc. will fall into a category that many of us in the astronomy hobby reference as "trash" scopes. You can always spot these telescopes because they usually advertise their magnification power on the box (i.e. – 575x, etc.). As a point of clarification, the main purpose of a telescope is not to magnify but rather collect light. Tasco, Jason, National Geographic, Vivitar, Bushnell, Cstar, Galileo and Edu Science are brands that sell in this cheap scope price point. Even the big boys like Meade and Celestron (that sell high end telescopes) sell in this cheap market area.
There are 3 major problems with these cheap telescopes.
First: Wobbly, Poor Quality Tripods/Mounts With a wobbly tripod, even the slightest breeze or gentle nudge may cause the telescope to move even a little bit causing the object you are looking at to move out of the field of view. Also these poor quality tripods/mounts lack the ability to make small, minor movements in order to keep the object in the field of view so you can track it as the earth rotates. With these mounts/tripods, you end up jerking the scope around losing the objects from your field of view and having to find/center it again. Just as a point of reference, Jupiter, at medium or high magnification, will move out of the field of view within 30 seconds.
Second: Horrible Finders A finder, which is mounted to main telescope tube, is a mini telescope with a much wider view of the sky that helps the user point the telescope to the spot in the sky you want to observe. Most finders on these cheap telescopes have lenses made of plastic and cannot be focused. When looking through the finder, the image is blurred and of almost no use. It's very, very difficult to point a telescope to an object in the sky just using the view from the telescope eyepiece. Typically the widest view you can get from one of these telescopes is around 1 degree. Now do the math with 180 degrees of sky in each direction, you're only looking at a very small patch of sky through the main telescope. If you don't have a good finder you will quickly give up in frustration trying to point the telescope.
Third: Poor Eyepieces and/or Diagonals More often than not, these cheaper telescopes come with 0.965" diameter eyepieces. Often they'll be marked with a prefix of R, SR or H depending on the design. These designs are some of the oldest around, dating back to the 17th & 18th centuries and introduce a lot of optical problems that more modern designs have corrected. The diagonal is a mirror that attaches to the back end of the telescope that creates a 90-degree shift in the light path so you don't have to strain your neck/back hunching over check out an image. Most poorly made diagonals scatter a lot of the light that you are trying to capture causing ghost images and difficulty achieving focus.
In summary, these cheaper telescopes will result not in a child that is inspired by the night sky but rather one that is frustrated with astronomy and that gift that ends up in the closet/garage collecting dust.
For more information, check out following good resources about telescopes on the Internet.
Purchasing a Telescope:
Cloudy Nights is one of the best resources for amateur astronomers out on the internet. There is a very helpful 3-part article titled "Starting Off Right in Astronomy" available: Part 1, Part 2, and Part 3.
Advice from the Raleigh Astronomy Club on purchasing a telescope is available in the article Purchasing a Telescope.
Already Have A Difficult To Use Telescope? So what if you have one of these telescopes already? Don't lose hope, you can make the most of what you have:
And finally, my own experience with a my first telescope, a cheap trash scope: http://home.earthlink.net/~sirius_star_gazer/ (click on the New To Astronomy link on the left hand side).
