Auburn Astronomical Society
In this Issue
It’s an excellent year for the Perseids.
The Perseid meteor shower, due to peak on the morning of Wednesday, August
12th, should put on a nice show – and may display a surprising new component.
This month’s meeting will be on Friday,
August 13, at 8:00PM in room 215 of the Aerospace
Engineering Building. Riders from the Montgomery area are welcome
to meet at the home of Russell Whigham, 518
Seminole Dr., and carpool over to Auburn. Plan to be ready to
leave for Auburn at 7:00PM.
Our star party this month will be the following
evening, Saturday, August 14 at Cliff
The Coronado PST Hydrogen-Alpha Solar telescope
and accessories that were ordered from Orion Telescopes have arrived and
will be on display at Friday’s meeting. Here’s what we have:
|24606 Coronado PST with EQ-1 Mount/Tripod
|07812 AstroTrack Drive for EQ-1
|08636 Electronic Color Imaging Eyepiece
|(5% Normal Shipping)
The decision was made to include the tripod and equatorial
mount with clock drive to make it a complete package for those who don’t
already have a driven scope on which to mount the PST.
The color electronic eyepiece was ordered at the
same time but is not dedicated to the solar scope and can be with any 1.25-inch
focuser. It has a RCA video output jack to be used with a TV monitor,
VHS tape, or other video medium to be supplied by the user. The sensitivity
is such that it will only be useful on solar system objects.
As we discussed at our June and July meetings,
the use of this scope will be primarily for official AAS events such as
Astronomy Day and our other public star parties. When not in use
at said events, it will be available to AAS members as a privilege of membership,
just as our 8-inch scope is now. Members should be familiar with
the use of German equatorial mount, and all safety concerns associated
with solar observing. Submit your request for a week or so, (based
on the number of members requesting loan of the scope), to Rhon Jenkins,
AAS, president. You can download a copy of the instructions at: http://www.coronadofilters.com/instructions/pstinstructionscopy.pdf
From one of the local observatories in
It appears that the STIS instrument on HST has
suffered a failure which leads the instrument inoperable. Details are provided
below. Although STIS was 7 years old (and well past its 5-year design life),
this loss will significantly affect the scientific output of Hubble. STIS
is the only spectrograph onboard HST, and about 30% of Hubble time went
to STIS observations. There are now no UV spectrographs in orbit that operate
in the 1200-3000 Angstrom range except for the low spectral resolution
prism on GALEX (FUSE operates from 900-1185A). In recent years, STIS
was the instrument used to (1) obtain the exquisite observations of the
transiting planet (HD209458), (2) make coronagraphic observations of proto-planetary
disks, (3) discover the hot intergalactic medium at low redshift, and (4)
carry out high spectral and spatial resolution observations of Eta Car
to in a Treasury program.
From Dr Glenn Schneider, NICMOS Team Scientist
It is indeed true - we have lost a - now - irreplaceable
resource in astronomy: STIS on HST. STIS is NICMOS's neighbor in
the Hubble Space Telescope's aft shroud. As NICMOS gives Hubble its infrared
eyes, the Space Telescope Imaging Spectrograph gives (gave) it its UV sight
with imaging, polarimetry, but it's real strength spectroscopy. Note
that there is no other high resolution spectrograph with access to the
vacuum ultraviolet. FUSE is complementary, but will not fill the
void with the loss of STIS. STIS was born along side of NICMOS at Ball
Aerospace in Boulder, Colorado, and rode together with NICMOS to HST where
they were installed during SM2. The Cosmic Origins Spectrograph,
slated for SM4 (built and now resting on the ground) would have aprox 20
times the sensitivity as STIS - but without an SM4 astronomy has been really
a real blow. Let us not take our space astronomy resources for granted.
No hardware lasts forever. Without servicing
HST's premature demise will soon be felt by astronomers worldwide - sooner
than some may have feared.
Here are some details.
Manager, HST Operations Project
Space Telescope, HST Operations Project/Code 441
DATE OF INCIDENT:
August 3, 2004 @ 16:38 GMT (12:38 PM EDT)
LOCATION OF INCIDENT: HST Space Telescope Imaging
DESCRIPTION OF INCIDENT - Updated 8-6-04:
On August 3, 2004 @ 16:38 GMT (12:38 PM EDT)
the Space Telescope ImagingSpectrograph (STIS) suspended after suffering
a failed command echo check between the Control Section (CS) of the STIS
Main Electronics Box (MEB) and the Multi-Anode Micro-channel Array (MAMA)
Control Electronics (MCE).
Accompanying the Suspend was an anomalous rapid
rise in the STIS input current of approximately 1A just prior to the Suspend
entry. Additionally, a voltage dropout of the
Main Electronics Box (MEB)/Support Electronics
+5 Volt power converter occurred approximately 43 minutes prior to the
Suspend. Further investigation has now revealed a probable failure
mechanism linking these anomaly signatures. Accordingly, it is now
believed that STIS's mechanism functions are inoperable and unrecoverable.
has been single-string in its electronics since
May 2001, it can no longer be used for science observations.
With support from the +5 Volt power converter
manufacturer (Interpoint), investigators have duplicated the power converter
failure under loading conditions nearlyidentical to that seen on-orbit.
The incipient failure is believed to have been in an inductor within the
power converter, which failed during the orbit night preceding the Suspend.
The inductor failure caused the power converter +5 volt output to drop
to zero volts, as seen in telemetry. Following this dropout the converter
remained relatively stable until entry into orbit day, after which slight
(and nominal) increases in its input voltage caused its current draw to
The large and rapid current draw resulted in the
1A increase in STIS input current noted in telemetry just prior to the
Suspend. Additionally, current limiter logic within the
electronics card housing the power converter
responded by reducing the supply voltage, which in turn caused a reduction
in voltage to the MAMA Control Electronics(MCE). This,
in turn, is believed to have caused the interface
communications failure with the Control Section and the subsequent Suspend
action. The MAMA detectors are believed to have been unharmed by
this sequence of events since they were not active (no high voltage on)
when the anomaly occurred.
The highly probable consequence of this scenario
is the total failure of the MEB/Support Electronics +5V power converter.
Since this component is essential to the operation of all
of the 8 mechanisms within the instrument (including
shutters), its demise renders those mechanisms inoperable. A re-configuration
to the Side 1 electronics (current operations are on Side 2) is not possible.
(The Side 1 electronics failed in May 2001.)
The instrument remains in Suspend mode. The Project
will convene a follow-up meeting on August 6, 2004 to continue the review
and analysis of data and to discuss a forward plan.
IMPACT ON PROGRAM/PROJECT AND SCHEDULE:
The STIS science program timeline was interrupted
when Suspend mode was entered. The Project and Space Telescope Science
Institute will cease scheduling STIS science. Alternate observations
from other instruments will replace STIS observations. All other
HST science instruments are functioning nominally.
The corrective actions to be taken are as follows:
Continue investigations and develop a plan to
confirm the proposed failure mechanism. Ball Aerospace, GSFC AETD,
Interpoint, ST ScI, and HST Program personnel are actively participating
in the investigation.
Assess the pros and cons of leaving the STIS
in Suspend mode versus Safe Mode, pending performance of possible tests.
Form a Failure Review Board to perform a thorough
investigation of the anomaly.
REPORT FILED BY:
John Gainsborough/Operations Manager/Code 441
Mike Prior/Observatory Systems Manager/Code 441
Deep South Regional
Star Gaze 2004
Thanks to the efforts of Len Philpot, the DSRSG
now has a website. It is really more of a one page road sign that
will direct people to this [DSRSG] group. The dates for this year’s
DSRSG are October 13 - 17, 2004, at Percy Quin State Park, McComb, Mississippi.
The web address is: http://www.stargazing.net/dsrsg/
. Once in the DSRSG Yahoo Group, go to files, and DSRSG 2004 Registration
and Liability Form.
by Eddie Kirkland
From Sunday through Thursday, July 18-22,
John Tatarchuk and I attended the Nebraska Star Party held in the Sandhills
of Nebraska near the town of Valentine. After almost 22 hours of
driving straight-through, we arrived at Merritt Reservoir, the site of
the star party and proceeded to unload and set up camp and scopes.
The observing field was much different than what we Easterners are familiar;
everyone was spread out over maybe 40-60 acres, our nearest neighbor was
about 50 yards away. Each observing site tended to be atop the rounded
grass-covered sand hills. Overall there were 300+ attendees.
Star Party – 2004
While waiting for darkness to arrive (at 10:30
!!), we had to endure 100 degree heat; to escape, we did some sightseeing
from the comfort of the air-conditioned truck. This was repeated
the next two days, while on the last two we enjoyed the much more moderate
The first night was very nice, living up to the
advertised 7.0+ magnitude skies (one guy reported 7.5 that night); I could
actually see shadows from the Milky Way, which was breathtaking.
We mainly viewed eye-candy objects that night such as the Veil, Lagoon,
Swan, Trifid, and Eagle nebulae, and the brighter galaxies such as M51,
M101, M33, and M31. Each of these objects revealed more detail than
I had ever seen; spirals were easily seen in M51, 101, and 33. John
also cataloged some of his illusive Abel planetaries. The central
star could be seen in moments of good seeing in the Ring Nebula.
Suffering from our drive out, I called it a night at 3:00; John made it
Monday and Tuesday nights were overcast with no
observing. Tuesday near dusk we enjoyed a nice lightning display
in the northwest until the storm got a little too close. All of a
sudden the canopy I was sitting under decided to go airborne, narrowly
missing our two scopes. As the wind increased John had to hold
onto his scope after his tarp started flapping wildly, while I sat inside
the truck and watched my tent get trashed. Luckily the storm skirted
us and John had an extra tent. Other than the tent, we survived;
others were not so lucky. We heard reports of scopes blown over and
one 18” dob lifted out of its rocker box. Several other tents were
sent tumbling or were trashed like mine. The next morning we saw
a beautifully constructed and finished homemade dob with wooden tube that
had been mangled.
Thursday night was another good one, only a little
less transparent than Sunday’s skies. However, it was quite windy
early on and we dob drivers were having a hard time keeping things steady.
For an hour or so, John and I had a couple youngsters and their grandparents
to show off some of the night sky’s wonders. Later on the winds died
down and we enjoyed a full night until nearly dawn. Friday night
had great promise but gave way to scattered clouds at times. One
thing we had to endure was an interruption of our observing by some pesky
aurora messing up our northern skies. For an hour or so we sat in
chairs and enjoyed the show. As we were heading back home the next
morning, I turned in a little early, while John stayed with it.
Overall we had the majority of three nights out
of five of good viewing under some really dark skies. There were
days that were miserably hot, but we survived. I was somewhat disappointed
in not having all nights clear, but that is just “one of those things”
that we can’t control. If (when?) I go back, it will be in a camper
with air conditioning at the nearby campground or in a motel.
by Eddie Kirkland
This year’s Fall Star Party at the Chiefland
Astronomy Village in Chiefland, FL will be held November 7-14. Anyone
interested attending may visit the website at http://www.chiefland.org/
. Please note that the event is now “Pre-registration only” and
registration forms must be in by October 1. Hope to see you there!!
Hoping to see everyone at the meeting,