Holmes history

Interesting details from the BAA Circular about Holmes -

In 1892, at its discovery, it reached 4th magnitude, and was visible
to the naked eye for several weeks. At that time it grew to about 30'
diam, and there was a second outburst a few months later which brought
it back to naked eye visibility.

I read somewhere that it will be in N hemisphere skies for the next 2
years .... could be interesting times ahead!

I got my first look through the telescope tonight (rather aged
Celestron C8) .... without the benefit of Pete's Registax, it's like a
translucent bubble, less distinct at one edge than the other -
presumably that's where the tail is, if anything. What I find awesome
is the sheer size of the thing, when you consider how far away it is,
compared say to the size of the Martian disc at opposition. BAA says
it's roughly a million Km in diameter just now!

Paul
Leigh
Lancs

here is some more history from the web site at
http://cometography.com:80/pcomets/017p.html

nice to know the history of things

enjoy eveyone, I think it's great, I even pointed people to the correct
location to find it in in the planetarium today!

--
StarDome - Astronomy - Astronautics - Planetarium
Mr Andrew R Green BSc(Hons) FRAS.
Fellow Royal Astronomical Society
Director & Resident Astronomer StarDome,
Director Anglo-Australian Astro Education Partnership

Discovery
E. Holmes (London, England) was a regular observer of the Andromeda galaxy
(M31), so he knew the region very well. On the evening of 1892 November 6,
with skies that were not very favorable, he finished making a few
observations of Jupiter and some double stars with his 32-cm reflector, and
then decided to take a quick look at the faint companions of Mu Andromedae
and the nearby galaxy M31 before quitting for the night. Upon turning the
reflector toward that region, he saw what he thought was M31 enter the field
of the finder, but when he looked through the eyepiece he saw something
different. Holmes said he "called out involuntarily, 'What is the matter?
There is something strange here.' My wife heard me and thought something had
happened to the instrument and came to see." The object in the field of
Holmes' telescope was a comet with a coma about 5 arc minutes across and
with a bright nucleus. The date was then November 6.98. Holmes was able to
determine a rough positon on November 7.03, before clouds moved in. He
immediately wrote to E. W. Maunder (Royal Observatory, Greenwich, England),
W. H. Maw (England), and Kidd (Bramley, England). Kidd immediately expressed
some skepticism about Holmes' find because of its nearness to M31; however,
on November 7.75, Kidd and Bartlett (Bramley) spotted the comet with the
naked eye. The comet was independently discovered by T. D. Anderson
(Edinburgh, Scotland) on November 8.9 and by J. E. Davidson (Mackay,
Queensland, Australia) on November 9.5.

Historical Highlights

· The comet's perihelion distance of over 2 AU made the initial orbits
somewhat discordant, especially in the perihelion date. The first orbit was
calculated by H. C. F. Kreutz using positions from November 9, 10, and 11.
The resulting perihelion date was 1892 August 16.24. During the next several
days, the perihelion date was given as April 19.92 by E. Weiss and April
20.04 by A. Berberich. Using positions obtained through November 17, Kreutz
demonstrated the difficulty in determining the orbit, as he gave four
parabolic orbits with perihelion dates ranging from February 28.82 to June
7.30 that each fit the available positions in a similar fashion. Prominent
astronomers on both sides of the Atlantic Ocean noted something particularly
interesting about the orbit of this comet around mid-November. Berberich
reported in a November 11 Circular issued by the Astronomische Nachrichten
and Boss reported in the November 18 issue of the Astronomical Journal that
this comet might be the lost comet 3D/Biela. The perihelion date was given
as December 28 by Berberich and December 27 by Boss.

· The first elliptical orbits were independently calculated by Kreutz and
Searle using positions spanning the period of November 9 to 17. Kreutz gave
the perihelion date as June 10.46 and the period as 7.09 years. Searle gave
the perihelion date as October 12.48 and the period as 6.14 years.
Additional orbits by L. Boss, L. Schulhof, Berberich, V. Cerulli, and J. R.
Hind eventually established the perihelion date as June 13 and the period as
6.9 years. These orbits proved that this comet was not a return of 3D/Biela.

· The comet had passed perihelion nearly five months before discovery and
had passed closest to Earth just a month before. As astronomers would later
realize, it was discovered during an apparent outburst in brightness. Nearly
every astronomer reported the comet was visible to the naked eye through the
first half of November, but few made actual total magnitude estimates. E. E.
Barnard (Lick Observatory, California, USA) said the comet "was easily
visible to the naked eye, as a small hazy star, and almost exactly as bright
as the brightest part" of the galaxy M31 on the 9th. The comet faded
throughout the second half of November, but it was still a naked-eye object
until the last days of this period. Although no actual total magnitude
estimates were made, a couple of astronomers made observations that give
clues to the comet's brightness. G. Gruss (Prague, Czech Republic) said it
was very easy to see in the 5-cm finder on the 23rd and he said it seemed
brighter on the 24th, while M. Updegraff (State University of Missouri) said
it was barely visible to the naked eye after the moon had set on the 26th.
Moonlight blocked the comet from view as December began. On the December 6,
H. A. Kobold (Strasbourg, France) described the comet as a shapeless
nebulosity, without a distinct condensation. F. Ristenpart (Karlsruhe,
Germany) said the comet could barely be seen by averted vision in the 15-cm
refractor on the 7th. J. Tebbutt (Windsor, New South Wales, Australia) said
the comet was "of the last degree of faintness" in the 11-cm refractor on
the 7th and 8th. On 1893 January 5, Barnard viewed the comet at low power in
the 30-cm refractor and said the comet appeared very large and very faint,
while Kobold said the 46-cm refractor revealed a faint spot of nebulosity
about 2 arc minutes across which was only visible with great effort. Kobold
noted the comet was next to a star of magnitude 10 on the 12th and was very
difficult to see. The coma was about 30 arc seconds across.

· The comet experienced another outburst in brightness around January 16.
Kobold noted the comet was visible to the naked eye on January 16.81 and
said a telescope revealed a nucleus of magnitude 8 and a coma 41 arc seconds
across. At about the same time, J. Palisa (Vienna, Austria) also found the
comet shining like a star of magnitude 8, and gave the coma diameter as 20
arc seconds. Observations made on the 17th indicated the comet had not
changed in brightness, but exhibited a larger coma than on the previous
night. A 30-minute exposure by I. Roberts (England) revealed "a very dense
circular nucleus surrounded by symmetrical nebulosity, which gave the comet
the appearance of a nebulous star." He measured the coma as 39 arc seconds
across and the nuclear condensation as 14 arc seconds across.

· The comet steadily faded after the mid-January outburst. Its position was
measured for the final time on March 13.79, when Palisa found it with the
69-cm refractor and described it as extremely faint. The final observations
of the comet were made by H. C. Wilson (Goodsell Observatory, Northfield,
Minnesota) on April 4 and Kobold on April 6.9. Wilson observed with a 41-cm
refractor and described the comet as "exceedingly faint" with a coma about 2
arc minutes across and "very slight" central condensation. Kobold said it as
"extremely faint" and added that it was impossible to measure the position
"on this and on several following evenings." Wilson again looked for the
comet in the 41-cm refractor on August 16 and September 14, but no trace was
found. He took a photograph of the region where the comet was expected to be
on 1894 January 12. The exposure was made with the 15-cm camera and the
exposure was one hour in duration. Although a slightly oval stain about 20
arc minutes across and with no condensation was seen at the correct spot, He
noted it was "so suspiciously like a dirty water stain that we hesitate to
say anything about it without verification."

· Predictions for the 1899 return came from E. Kohlschütter (1896) and H.
J. Zwiers (1895, 1897, 1899). Both astronomers made careful investigations
of the comet's discovery apparition of 1892-3, but where Kohlschütter did
not apply perturbations between that apparition and 1899, Zwiers carefully
determined the effects Jupiter and Saturn would have on the comet's motion.
The ultimate result was that Kohlschütter predicted a perihelion date of
1899 May 8.51, while Zwiers ultimately predicted it as April 28.17. Zwiers
(1899) wrote that the comet would have been favorably situated for recovery
during the Spring of 1898 for observers in the Southern Hemisphere though it
could have been just out of range of their telescopes. The failure to find
the comet made a recovery during the autumn of 1899 very important. The
comet was recovered by C. D. Perrine (Lick Observatory, California) with a
91-cm refractor on 1899 June 11.46. His measured position indicated Zwiers'
perihelion date required a correction of only +0.43 day. Perrine said the
comet was not brighter than magnitude 16. He described it as a "round
nebulous mass about 30" in diameter, with only a slight brightening at the
center." The comet was only observed at Lick Observatory and Yerkes
Observatory (Wisconsin) using large refractors of 91-cm and 102-cm,
respectively. Although the magnitude estimates seem to jump around a bit,
their sparse distribution and lack of confirming observations makes it
difficult to determine if the variations were because the comet was still
experiencing outbursts or because of other factors. The comet's brightest
reported magnitude was 13 by E. E. Barnard (Yerkes Observatory) on August
16. The comet was last detected on 1900 January 21.26 by Perrine. The
observation was made with the 91-cm refractor and he described the comet as
very faint, with a magnitude of 16.

· Zwiers (1906) took 21 positions from the 1899 apparition and determined a
refined orbit. He than applied perturbations from Jupiter for the period of
1899 January to 1906 April and predicted the comet would next pass
perihelion on 1906 March 14.68.

· The comet was lost after the 1906 apparition, despite predictions at
virtually every return thereafter. By the time of the 1942 return, a rough
prediction by J. T. Foxell and K. Pollock noted that recovery seemed
doubtful.

· In the December 1963 issue of the Astronomical Journal B. G. Marsden
integrated the motion of comet Holmes from 1899 to 1975 using a high-speed
computer. He found that between the comet's last observed appearance in 1906
and the upcoming apparition of 1964, the orbital period should have
increased from 6.86 years to 7.35 years, and the perihelion distance should
have increased from 2.121 AU to 2.347 AU. The resulting prediction for the
comet's next perihelion date was 1964 November 15.36. The comet was
recovered by E. Roemer (U. S. Naval Observatory, Flagstaff station, Arizona)
on 1964 July 16.31. She determined the magnitude as 19.2 and described the
comet as very sharply condensed, with only a trace of coma. Additional
plates were obtained on July 17.33, which revealed the same physical
characteristics. Due to the weakness of the July images, additional
confirmation was needed, and Roemer obtained this on September 11.23. The
magnitude was determined as 18.7, and the comet was again described as very
sharply condensed, with only a trace of coma. The precise positions
indicated Marsden's prediction needed to be corrected by only +0.7 day. The
comet has been observed at every return since 1964.

· Apparition of 2007: OUTBURST The comet was observed at about magnitude
14.5 since July and had showed signs of a slow fading; however, very early
on the morning of October 24, Juan Antonio HenrÂ'quez Santana (Spain)
reported that the comet was much brighter than expected. This was all
rapidly confirmed. One comet observer, Bob King (Minnesota, USA), made one
of the confirming observations on October 24.17 and gave the magnitude as
7.1. He described it as appearing like a yellowish star. Interestingly, he
reobserved the comet on October 24.47 and gave the magnitude as 4.0 with the
naked eye!! Seiichi Yoshida (Japan) observed the comet on October 24.55 and
gave the naked-eye magnitude as 3.5. Further observations by Yoshida gave
the naked-eye magnitude as 3.0 on October 24.63 and 2.8 on October 24.72.
Through the end of October, most observers were reporting the comet holding
at magnitude 2.6-2.8.






"Paul Richardson" wrote in message
news
Interesting details from the BAA Circular about Holmes -

In 1892, at its discovery, it reached 4th magnitude, and was visible
to the naked eye for several weeks. At that time it grew to about 30'
diam, and there was a second outburst a few months later which brought
it back to naked eye visibility.

I read somewhere that it will be in N hemisphere skies for the next 2
years .... could be interesting times ahead!

I got my first look through the telescope tonight (rather aged
Celestron C8) .... without the benefit of Pete's Registax, it's like a
translucent bubble, less distinct at one edge than the other -
presumably that's where the tail is, if anything. What I find awesome
is the sheer size of the thing, when you consider how far away it is,
compared say to the size of the Martian disc at opposition. BAA says
it's roughly a million Km in diameter just now!

Paul
Leigh
Lancs